fix: define a correct zero value for an not initialized interface{}

.github/ISSUE_TEMPLATE/bug_report.md

@@ -17,11 +17,11 @@ func main() {
 Expected result:
 ```console
 $ go run ./sample.go
-// ouput
+// output
 ```
 
 Got:
 ```console
 $ yaegi ./sample.go
-// ouput
+// output
 ```

.golangci.toml

@@ -5,7 +5,7 @@
 [linters-settings]
 
   [linters-settings.govet]
-    check-shadowing = true
+    check-shadowing = false
 
   [linters-settings.gocyclo]
     min-complexity = 12.0
@@ -32,7 +32,11 @@
     "gocyclo",
     "gochecknoinits",
     "gochecknoglobals",
-    "typecheck", # v1.17.1 and Go1.13 => bug
+    "wsl",
+    "godox",
+    "funlen",
+    "gocognit",
+    "stylecheck",
   ]
 
 [issues]
@@ -41,10 +45,13 @@
   max-same-issues = 0
   exclude = []
 
-  [[issues.exclude-rules]]
-    path = "cmd/goexports/goexports.go"
-    text = "SA1019: importer.For is deprecated: use ForCompiler, which populates a FileSet with the positions of objects created by the importer."
-
   [[issues.exclude-rules]]
     path = "interp/.+_test\\.go"
     linters = ["goconst"]
+
+  [[issues.exclude-rules]]
+    path = "interp/interp.go"
+    text = "`in` can be `io.Reader`"
+  [[issues.exclude-rules]]
+    path = "interp/interp.go"
+    text = "`out` can be `io.Writer`"

.travis.yml

@@ -19,7 +19,6 @@ cache:
 matrix:
   fast_finish: true
   include:
-    - go: 1.11.x
     - go: 1.12.x
     - go: 1.13.x
       env: STABLE=true

CONTRIBUTING.md

@@ -13,7 +13,12 @@ discussions.
 Once the proposal is approved, a Pull Request can be opened. If you want
 to provide early visibility to reviewers, create a [Draft Pull Request].
 
+We will also require you to sign the [Containous Contributor License Agreement]
+after you submit your first pull request to this project. The link to sign the
+agreement will be presented to you in the web interface of the pull request.
+
 [Issues]: https://github.com/containous/yaegi/issues
 [Pull Requests]: https://github.com/containous/yaegi/issues
 [Feature Request]: https://github.com/containous/yaegi/issues/new?template=feature_request.md
 [Draft Pull Request]: https://github.blog/2019-02-14-introducing-draft-pull-requests/
+[Containous Contributor License Agreement]: https://cla-assistant.io/containous/yaegi

Makefile

@@ -18,5 +18,6 @@ generate: gen_all_syscall
 
 tests:
 	GO111MODULE=off go test -v ./...
+	GO111MODULE=off go test -race ./interp
 
 .PHONY: check gen_all_syscall gen_tests

README.md

@@ -129,6 +129,24 @@ $ yaegi cmd/yaegi/yaegi.go
 >
 ```
 
+Or for Go scripting in the shebang line:
+
+```console
+$ cat /tmp/test
+#!/usr/bin/env yaegi
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("test")
+}
+$ ls -la /tmp/test
+-rwxr-xr-x 1 dow184 dow184 93 Jan  6 13:38 /tmp/test
+$ /tmp/test
+test
+```
+
 ## Documentation
 
 Documentation about Yaegi commands and libraries can be found at usual [godoc.org][docs].

_test/a33.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]int{1, 2, 3}
+	b := a
+	fmt.Println(b)
+}
+
+// Output:
+// [1 2 3]

_test/a34.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]int{1, 2, 3}
+	var b [3]int = a
+	fmt.Println(b)
+}
+
+// Output:
+// [1 2 3]

_test/a35.go

@@ -0,0 +1,13 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]int{1, 2, 3}
+	b := a
+	b[0] = -1
+	fmt.Println(a)
+}
+
+// Output:
+// [1 2 3]

_test/a36.go

@@ -0,0 +1,13 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]int{1, 2, 3}
+	var b [3]int = a
+	b[0] = -1
+	fmt.Println(a)
+}
+
+// Output:
+// [1 2 3]

_test/a37.go

@@ -0,0 +1,11 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]int{1, 2, 3}
+	fmt.Println(a)
+}
+
+// Output:
+// [1 2 3]

_test/a38.go

@@ -0,0 +1,11 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]byte{}
+	fmt.Printf("%T\n", a)
+}
+
+// Output:
+// [0]uint8

_test/a39.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]byte{}
+	b := a
+	fmt.Printf("%T %T\n", a, b)
+}
+
+// Output:
+// [0]uint8 [0]uint8

_test/assign10.go

@@ -0,0 +1,10 @@
+package main
+
+func main() {
+	var a uint
+	a = 1 + 2
+	println(a)
+}
+
+// Output:
+// 3

_test/b1/foo/foo.go

@@ -0,0 +1,7 @@
+package foo
+
+import bar "github.com/containous/yaegi/_test/b2/foo"
+
+var Desc = "in b1/foo"
+
+var Desc2 = Desc + bar.Desc

_test/b2/foo/foo.go

@@ -0,0 +1,3 @@
+package foo
+
+var Desc = "in b2/foo"

_test/bin2.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func main() {
+	fmt.Println(math.Abs(-5))
+}
+
+// Output:
+// 5

_test/closure8.go

@@ -0,0 +1,10 @@
+package main
+
+var f = func(a int) int { return 2 + a }
+
+func main() {
+	println(f(3))
+}
+
+// Output:
+// 5

_test/complex1.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	var c complex128
+	c = 1
+	fmt.Printf("%T %v\n", c, c)
+}
+
+// Output:
+// complex128 (1+0i)

_test/complex2.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	c := complex(1, 0)
+	c += 1
+	fmt.Printf("%T %v\n", c, c)
+}
+
+// Output:
+// complex128 (2+0i)

_test/complex3.go

@@ -0,0 +1,11 @@
+package main
+
+import "fmt"
+
+func main() {
+	var s int = 1 + complex(1, 0)
+	fmt.Printf("%T %v\n", s, s)
+}
+
+// Output
+// int 2

_test/composite3.go

@@ -0,0 +1,12 @@
+package main
+
+func main() {
+	var err error
+	var ok bool
+
+	_, ok = err.(interface{ IsSet() bool })
+	println(ok)
+}
+
+// Output:
+// false

_test/composite4.go

@@ -0,0 +1,11 @@
+package main
+
+func main() {
+	var err error
+
+	_, ok := err.(interface{ IsSet() bool })
+	println(ok)
+}
+
+// Output:
+// false

_test/ct/ct1.go

@@ -0,0 +1,3 @@
+package ct
+
+func init() { println("hello from ct1") }

_test/ct/ct2.go

@@ -0,0 +1,5 @@
+// +build !dummy
+
+package ct
+
+func init() { println("hello from ct2") }

_test/ct/ct3.go

@@ -0,0 +1,5 @@
+// +build dummy
+
+package ct
+
+func init() { println("hello from ct3") }

_test/foo-bar/foo-bar.go

@@ -0,0 +1,3 @@
+package bar
+
+var Name = "foo-bar"

_test/for7.go

@@ -0,0 +1,9 @@
+package main
+
+func main() {
+	for i := 0; i; {
+	}
+}
+
+// Error:
+// 4:14: non-bool used as for condition

_test/for8.go

@@ -0,0 +1,18 @@
+package main
+
+func main() {
+	for i := 0; i < 4; i++ {
+		for {
+			break
+		}
+		if i == 1 {
+			continue
+		}
+		println(i)
+	}
+}
+
+// Output:
+// 0
+// 2
+// 3

_test/fun10.go

@@ -0,0 +1,19 @@
+package main
+
+import "fmt"
+
+func f() func() {
+	return nil
+}
+
+func main() {
+	g := f()
+	fmt.Printf("%T %v\n", g, g)
+	if g == nil {
+		fmt.Println("nil func")
+	}
+}
+
+// Output:
+// func() <nil>
+// nil func

_test/fun11.go

@@ -0,0 +1,12 @@
+package main
+
+var f F
+
+type F func(int)
+
+func main() {
+	println("ok")
+}
+
+// Output:
+// ok

_test/if2.go

@@ -0,0 +1,13 @@
+package main
+
+import "fmt"
+
+func main() {
+	var i int
+	if i % 1000000 {
+		fmt.Println("oops")
+	}
+}
+
+// Error:
+// 7:5: non-bool used as if condition

_test/import7.go

@@ -0,0 +1,10 @@
+package main
+
+import "github.com/containous/yaegi/_test/foo-bar"
+
+func main() {
+	println(bar.Name)
+}
+
+// Output:
+// foo-bar

_test/import8.go

@@ -0,0 +1,10 @@
+package main
+
+import "github.com/containous/yaegi/_test/b1/foo"
+
+func main() {
+	println(foo.Desc)
+}
+
+// Output:
+// in b1/foo

_test/interface12.go

@@ -0,0 +1,18 @@
+package main
+
+type I1 interface {
+	Truc()
+}
+
+type T1 struct{}
+
+func (T1) Truc() { println("in T1 truc") }
+
+var x I1 = T1{}
+
+func main() {
+	x.Truc()
+}
+
+// Output:
+// in T1 truc

_test/interface13.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+)
+
+type X struct{}
+
+func (X) Foo() int {
+	return 1
+}
+func (X) Bar() int {
+	return 2
+}
+
+type Foo interface {
+	Foo() int
+}
+type Bar interface {
+	Bar() int
+}
+
+func main() {
+	var x X
+	var i Foo = x
+	j := i.(Bar)
+
+	fmt.Println(j.Bar())
+}
+
+// Output:
+// 2

_test/interface14.go

@@ -0,0 +1,17 @@
+package main
+
+type T struct{}
+
+func (t *T) Error() string { return "T: error" }
+
+var invalidT = &T{}
+
+func main() {
+	var err error
+	if err != invalidT {
+		println("ok")
+	}
+}
+
+// Output:
+// ok

_test/interface15.go

@@ -0,0 +1,28 @@
+package main
+
+type Fooer interface {
+	Foo() string
+}
+
+type Barer interface {
+	//fmt.Stringer
+	Fooer
+	Bar()
+}
+
+type T struct{}
+
+func (t *T) Foo() string { return "T: foo" }
+func (*T) Bar()          { println("in bar") }
+
+var t = &T{}
+
+func main() {
+	var f Barer
+	if f != t {
+		println("ok")
+	}
+}
+
+// Output:
+// ok

_test/interface16.go

@@ -0,0 +1,25 @@
+package main
+
+import "fmt"
+
+type Barer interface {
+	fmt.Stringer
+	Bar()
+}
+
+type T struct{}
+
+func (*T) String() string { return "T: nothing" }
+func (*T) Bar()           { println("in bar") }
+
+var t = &T{}
+
+func main() {
+	var f Barer
+	if f != t {
+		println("ok")
+	}
+}
+
+// Output:
+// ok

_test/interface17.go

@@ -0,0 +1,17 @@
+package main
+
+type T struct{}
+
+func (t T) Error() string { return "T: error" }
+
+var invalidT = T{}
+
+func main() {
+	var err error
+	if err != invalidT {
+		println("ok")
+	}
+}
+
+// Output:
+// ok

_test/interface18.go

@@ -0,0 +1,18 @@
+package main
+
+type T struct{}
+
+func (t *T) Error() string { return "T: error" }
+func (*T) Foo()            { println("foo") }
+
+var invalidT = &T{}
+
+func main() {
+	var err error
+	if err != invalidT {
+		println("ok")
+	}
+}
+
+// Output:
+// ok

_test/interface19.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+var I interface{}
+
+func main() {
+	fmt.Printf("%T %v\n", I, I)
+}
+
+// Output:
+// <nil> <nil>

_test/map19.go

@@ -0,0 +1,16 @@
+package main
+
+import "fmt"
+
+type cmap struct {
+	servers map[int64]*server
+}
+
+type server struct {
+	cm *cmap
+}
+
+func main() {
+	m := cmap{}
+	fmt.Println(m)
+}

_test/math1.go

@@ -0,0 +1,13 @@
+package main
+
+import "math"
+
+func main() {
+	var f float32
+	if f < math.MaxFloat32 {
+		println("ok")
+	}
+}
+
+// Output:
+// ok

_test/method28.go

@@ -0,0 +1,18 @@
+package main
+
+import "fmt"
+
+type T struct {
+	Name string
+}
+
+func (T) create() *T {
+	return &T{"Hello"}
+}
+
+func main() {
+	fmt.Println(T{}.create())
+}
+
+// Output:
+// &{Hello}

_test/method29.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"context"
+	"net"
+)
+
+var lookupHost = net.DefaultResolver.LookupHost
+
+func main() {
+	res, err := lookupHost(context.Background(), "localhost")
+	println(len(res) > 0, err == nil)
+}
+
+// Output:
+// true true

_test/method30.go

@@ -0,0 +1,20 @@
+package main
+
+type T struct {
+	Name string
+}
+
+func (t *T) foo(a string) string {
+	return t.Name + a
+}
+
+var g = &T{"global"}
+
+var f = g.foo
+
+func main() {
+	println(f("-x"))
+}
+
+// Output:
+// global-x

_test/nil0.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func f() (host, port string, err error) {
+	return "", "", nil
+}
+
+func main() {
+	h, p, err := f()
+	fmt.Println(h, p, err)
+}
+
+// Output:
+//   <nil>

_test/nil1.go

@@ -0,0 +1,12 @@
+package main
+
+func main() {
+	var a error = nil
+
+	if a == nil || a.Error() == "nil" {
+		println("a is nil")
+	}
+}
+
+// Output:
+// a is nil

_test/op4.go

@@ -0,0 +1,9 @@
+package main
+
+func main() {
+	i := 100
+	println(i % 1e2)
+}
+
+// Output:
+// 0

_test/or0.go

@@ -0,0 +1,9 @@
+package main
+
+func main() {
+	c := false
+	println(c || !c)
+}
+
+// Output:
+// true

_test/or1.go

@@ -0,0 +1,9 @@
+package main
+
+func main() {
+	c := false
+	println(!c || c)
+}
+
+// Output:
+// true

_test/primes.go

@@ -0,0 +1,26 @@
+package main
+
+func Primes(n int) int {
+	var xs []int
+	for i := 2; len(xs) < n; i++ {
+		ok := true
+		for _, x := range xs {
+			if i%x == 0 {
+				ok = false
+				break
+			}
+		}
+		if !ok {
+			continue
+		}
+		xs = append(xs, i)
+	}
+	return xs[n-1]
+}
+
+func main() {
+	println(Primes(3))
+}
+
+// Output:
+// 5

_test/range0.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	v := []int{1, 2, 3}
+	for i := range v {
+		v = append(v, i)
+	}
+	fmt.Println(v)
+}
+
+// Output:
+// [1 2 3 0 1 2]

_test/range1.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]int{2, 1, 0}
+	for _, v := range a {
+		a[v] = v
+	}
+	fmt.Println(a)
+}
+
+// Output:
+// [0 1 2]

_test/range2.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := [...]int{2, 1, 0}
+	for _, v := range &a {
+		a[v] = v
+	}
+	fmt.Println(a)
+}
+
+// Output:
+// [2 1 2]

_test/range3.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	m := map[int]bool{1: true, 3: true, 5: true}
+	for k := range m {
+		m[k*2] = true
+	}
+	fmt.Println("ok")
+}
+
+// Output:
+// ok

_test/range4.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func main() {
+	m := map[int]bool{1: true, 3: true, 5: true}
+	for _, v := range m {
+		fmt.Println(v)
+	}
+}
+
+// Output:
+// true
+// true
+// true

_test/range5.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func main() {
+	m := map[int]bool{1: true, 3: true, 5: true}
+	var n int
+	for range m {
+		n++
+	}
+	fmt.Println(n)
+}
+
+// Output:
+// 3

_test/range6.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func main() {
+	m := map[float64]bool{math.NaN(): true, math.NaN(): true, math.NaN(): true}
+	for _, v := range m {
+		fmt.Println(v)
+	}
+}
+
+// Output:
+// true
+// true
+// true

_test/ret7.go

@@ -0,0 +1,11 @@
+package main
+
+func one() uint {
+	return 1
+}
+func main() {
+	println(one())
+}
+
+// Output:
+// 1

_test/str3.go

@@ -0,0 +1,11 @@
+package main
+
+import "strconv"
+
+func main() {
+	str := strconv.Itoa(101)
+	println(str[0] == '1')
+}
+
+// Output:
+// true

_test/str4.go

@@ -0,0 +1,11 @@
+package main
+
+import "unicode/utf8"
+
+func main() {
+	r, _ := utf8.DecodeRuneInString("Hello")
+	println(r < utf8.RuneSelf)
+}
+
+// Output:
+// true

_test/struct29.go

@@ -0,0 +1,19 @@
+package main
+
+type T1 struct {
+	A []T2
+	B []T2
+}
+
+type T2 struct {
+	name string
+}
+
+var t = T1{}
+
+func main() {
+	println("ok")
+}
+
+// Output:
+// ok

_test/struct30.go

@@ -0,0 +1,19 @@
+package main
+
+type T1 struct {
+	A []T2
+	M map[uint64]T2
+}
+
+type T2 struct {
+	name string
+}
+
+var t = T1{}
+
+func main() {
+	println("ok")
+}
+
+// Output:
+// ok

_test/switch21.go

@@ -0,0 +1,17 @@
+package main
+
+import "fmt"
+
+func main() {
+	var err error
+
+	switch v := err.(type) {
+	case fmt.Formatter:
+		println("formatter")
+	default:
+		fmt.Println(v)
+	}
+}
+
+// Output:
+// <nil>

_test/switch22.go

@@ -0,0 +1,21 @@
+package main
+
+type T struct {
+	Name string
+}
+
+func f(t interface{}) {
+	switch ext := t.(type) {
+	case *T:
+		println("*T", ext.Name)
+	default:
+		println("unknown")
+	}
+}
+
+func main() {
+	f(&T{"truc"})
+}
+
+// Output:
+// *T truc

_test/tag0.go

@@ -0,0 +1,15 @@
+// The following comment line has the same effect as 'go run -tags=dummy'
+//yaegi:tags dummy
+
+package main
+
+import _ "github.com/containous/yaegi/_test/ct"
+
+func main() {
+	println("bye")
+}
+
+// Output:
+// hello from ct1
+// hello from ct3
+// bye

_test/time10.go

@@ -0,0 +1,13 @@
+package main
+
+import "time"
+
+var UnixTime func(int64, int64) time.Time
+
+func main() {
+	UnixTime = time.Unix
+	println(UnixTime(1e9, 0).In(time.UTC).Minute())
+}
+
+// Output:
+// 46

_test/time11.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+const df = time.Minute * 30
+
+func main() {
+	fmt.Printf("df: %v %T\n", df, df)
+}
+
+// Output:
+// df: 30m0s time.Duration

_test/time9.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func main() {
+	fmt.Println((5 * time.Minute).Seconds())
+}
+
+// Output:
+// 300

_test/var10.go

@@ -0,0 +1,11 @@
+package main
+
+var _ = true
+var _ = "hello"
+
+func main() {
+	println("hello")
+}
+
+// Output:
+// hello

_test/var11.go

@@ -0,0 +1,10 @@
+package main
+
+var a, _, _, b = 1, true, "foo", 2
+
+func main() {
+	println(a, b)
+}
+
+// Output:
+// 1 2

_test/var9.go

@@ -0,0 +1,11 @@
+package main
+
+var a = "sdofjsdfj"
+var z = a[0:2]
+
+func main() {
+	println(z)
+}
+
+// Output:
+// sd

cmd/goexports/goexports.go

@@ -1,7 +1,7 @@
 //go:generate go build
 
 /*
-Goexports generates wrappers of package exported symbols
+Goexports generates wrappers of package exported symbols.
 
 Output files are written in the current directory, and prefixed with the go version.
 
@@ -26,6 +26,7 @@ import (
 	"go/constant"
 	"go/format"
 	"go/importer"
+	"go/token"
 	"go/types"
 	"io/ioutil"
 	"log"
@@ -114,7 +115,7 @@ type Wrap struct {
 }
 
 func genContent(dest, pkgName, license string) ([]byte, error) {
-	p, err := importer.For("source", nil).Import(pkgName)
+	p, err := importer.ForCompiler(token.NewFileSet(), "source", nil).Import(pkgName)
 	if err != nil {
 		return nil, err
 	}
@@ -147,7 +148,12 @@ func genContent(dest, pkgName, license string) ([]byte, error) {
 		pname := path.Base(pkgName) + "." + name
 		switch o := o.(type) {
 		case *types.Const:
-			val[name] = Val{fixConst(pname, o.Val()), false}
+			if b, ok := o.Type().(*types.Basic); ok && (b.Info()&types.IsUntyped) != 0 {
+				// convert untyped constant to right type to avoid overflow
+				val[name] = Val{fixConst(pname, o.Val()), false}
+			} else {
+				val[name] = Val{pname, false}
+			}
 		case *types.Func:
 			val[name] = Val{pname, false}
 		case *types.Var:
@@ -248,7 +254,14 @@ func genContent(dest, pkgName, license string) ([]byte, error) {
 
 // fixConst checks untyped constant value, converting it if necessary to avoid overflow
 func fixConst(name string, val constant.Value) string {
-	if val.Kind() == constant.Int {
+	switch val.Kind() {
+	case constant.Float:
+		str := val.ExactString()
+		if _, err := strconv.ParseFloat(str, 32); err == nil {
+			return "float32(" + name + ")"
+		}
+		return name
+	case constant.Int:
 		str := val.ExactString()
 		i, err := strconv.ParseInt(str, 0, 64)
 		if err == nil {
@@ -265,8 +278,10 @@ func fixConst(name string, val constant.Value) string {
 		if err == nil {
 			return "uint64(" + name + ")"
 		}
+		return name
+	default:
+		return name
 	}
-	return name
 }
 
 // genLicense generates the correct LICENSE header text from the provided

cmd/yaegi/yaegi.go

@@ -8,7 +8,7 @@ If invoked with no arguments, it processes the standard input
 in a Read-Eval-Print-Loop. A prompt is displayed if standard input
 is a terminal.
 
-Given a file, it operates on that file. if the first line starts with
+Given a file, it operates on that file. If the first line starts with
 "#!/usr/bin/env yaegi", and the file has exec permission, then the file
 can be invoked directly from the shell.
 
@@ -18,7 +18,10 @@ at global level in an implicit main package.
 
 Options:
     -i
-	   start an interactive REPL after file execution
+	   start an interactive REPL after file execution.
+	-tags tag,list
+	   a comma-separated list of build tags to consider satisfied during
+	   the interpretation.
 
 Debugging support (may be removed at any time):
   YAEGI_AST_DOT=1
@@ -43,7 +46,9 @@ import (
 
 func main() {
 	var interactive bool
+	var tags string
 	flag.BoolVar(&interactive, "i", false, "start an interactive REPL")
+	flag.StringVar(&tags, "tags", "", "set a list of build tags")
 	flag.Usage = func() {
 		fmt.Println("Usage:", os.Args[0], "[options] [script] [args]")
 		fmt.Println("Options:")
@@ -53,7 +58,7 @@ func main() {
 	args := flag.Args()
 	log.SetFlags(log.Lshortfile)
 
-	i := interp.New(interp.Options{GoPath: build.Default.GOPATH})
+	i := interp.New(interp.Options{GoPath: build.Default.GOPATH, BuildTags: strings.Split(tags, ",")})
 	i.Use(stdlib.Symbols)
 	i.Use(interp.Symbols)
 
@@ -79,9 +84,9 @@ func main() {
 		}
 
 		if interactive {
-			i.Repl(os.Stdin, os.Stdout)
+			i.REPL(os.Stdin, os.Stdout)
 		}
 	} else {
-		i.Repl(os.Stdin, os.Stdout)
+		i.REPL(os.Stdin, os.Stdout)
 	}
 }

cmd/yaegi/yaegi_test.go

@@ -0,0 +1,91 @@
+package main
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestYaegiCmdCancel(t *testing.T) {
+	tmp, err := ioutil.TempDir("", "yaegi-")
+	if err != nil {
+		t.Fatalf("failed to create tmp directory: %v", err)
+	}
+	defer func() {
+		err = os.RemoveAll(tmp)
+		if err != nil {
+			t.Errorf("failed to clean up %v: %v", tmp, err)
+		}
+	}()
+
+	yaegi := filepath.Join(tmp, "yaegi")
+	build := exec.Command("go", "build", "-race", "-o", yaegi, ".")
+	err = build.Run()
+	if err != nil {
+		t.Fatalf("failed to build yaegi command: %v", err)
+	}
+
+	// Test src must be terminated by a single newline.
+	tests := []string{
+		"for {}\n",
+		"select {}\n",
+	}
+	for _, src := range tests {
+		cmd := exec.Command(yaegi)
+		in, err := cmd.StdinPipe()
+		if err != nil {
+			t.Errorf("failed to get stdin pipe to yaegi command: %v", err)
+		}
+		var outBuf, errBuf bytes.Buffer
+		cmd.Stdout = &outBuf
+		cmd.Stderr = &errBuf
+
+		// https://golang.org/doc/articles/race_detector.html#Options
+		cmd.Env = []string{`GORACE="halt_on_error=1"`}
+
+		err = cmd.Start()
+		if err != nil {
+			t.Fatalf("failed to start yaegi command: %v", err)
+		}
+
+		_, err = in.Write([]byte(src))
+		if err != nil {
+			t.Errorf("failed pipe test source to yaegi command: %v", err)
+		}
+		time.Sleep(100 * time.Millisecond)
+		err = cmd.Process.Signal(os.Interrupt)
+		if err != nil {
+			t.Errorf("failed to send os.Interrupt to yaegi command: %v", err)
+		}
+
+		_, err = in.Write([]byte("1+1\n"))
+		if err != nil {
+			t.Errorf("failed to probe race: %v", err)
+		}
+		err = in.Close()
+		if err != nil {
+			t.Errorf("failed to close stdin pipe: %v", err)
+		}
+
+		err = cmd.Wait()
+		if err != nil {
+			if cmd.ProcessState.ExitCode() == 66 { // See race_detector.html article.
+				t.Errorf("race detected running yaegi command canceling %q: %v", src, err)
+				if testing.Verbose() {
+					t.Log(&errBuf)
+				}
+			} else {
+				t.Errorf("error running yaegi command for %q: %v", src, err)
+			}
+			continue
+		}
+
+		if outBuf.String() != "context canceled\n2\n" {
+			t.Errorf("unexpected output: %q", &outBuf)
+		}
+	}
+}

example/pkg/pkg_test.go

@@ -69,7 +69,6 @@ func TestPackages(t *testing.T) {
 	for _, test := range testCases {
 		test := test
 		t.Run(test.desc, func(t *testing.T) {
-
 			goPath, err := filepath.Abs(test.goPath)
 			if err != nil {
 				t.Fatal(err)
@@ -116,7 +115,6 @@ func TestPackagesError(t *testing.T) {
 	for _, test := range testCases {
 		test := test
 		t.Run(test.desc, func(t *testing.T) {
-
 			// Init go interpreter
 			i := interp.New(interp.Options{GoPath: test.goPath})
 			i.Use(stdlib.Symbols) // Use binary standard library

go.mod

@@ -1,3 +1,3 @@
 module github.com/containous/yaegi
 
-go 1.11
+go 1.12

internal/genop/genop.go

@@ -10,7 +10,7 @@ import (
 
 const model = `package interp
 
-// Code generated by 'go run ../cmd/genop/genop.go'. DO NOT EDIT.
+// Code generated by 'go run ../internal/genop/genop.go'. DO NOT EDIT.
 
 import "reflect"
 
@@ -352,6 +352,30 @@ func {{$name}}(n *node) {
 	}
 }
 {{end}}
+{{range $name, $op := .Unary}}
+func {{$name}}Const(n *node) {
+	t := n.typ.rtype
+	v := n.child[0].rval
+	n.rval = reflect.New(t).Elem()
+
+	{{- if $op.Bool}}
+	n.rval.SetBool({{$op.Name}} v.Bool())
+	{{- else}}
+	switch t.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		n.rval.SetInt({{$op.Name}} v.Int())
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		n.rval.SetUint({{$op.Name}} v.Uint())
+	{{- if $op.Float}}
+	case reflect.Float32, reflect.Float64:
+		n.rval.SetFloat({{$op.Name}} v.Float())
+	case reflect.Complex64, reflect.Complex128:
+		n.rval.SetComplex({{$op.Name}} v.Complex())
+	{{- end}}
+	}
+	{{- end}}
+}
+{{end}}
 {{range $name, $op := .Comparison}}
 func {{$name}}(n *node) {
 	tnext := getExec(n.tnext)
@@ -427,148 +451,6 @@ func {{$name}}(n *node) {
 				}
 			}
 		}
-	{{- if $op.Complex}}
-	case isComplex(t0) || isComplex(t1):
-		switch {
-		case c0.rval.IsValid():
-			s0 := vComplex(c0.rval)
-			v1 := genValueComplex(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s1 := v1(f)
-					if s0 {{$op.Name}} s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				n.exec = func(f *frame) bltn {
-					_, s1 := v1(f)
-					dest(f).SetBool(s0 {{$op.Name}} s1)
-					return tnext
-				}
-			}
-		case c1.rval.IsValid():
-			s1 := vComplex(c1.rval)
-			v0 := genValueComplex(c0)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					if s0 {{$op.Name}} s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					dest(f).SetBool(s0 {{$op.Name}} s1)
-					return tnext
-				}
-			}
-		default:
-			v0 := genValueComplex(n.child[0])
-			v1 := genValueComplex(n.child[1])
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					_, s1 := v1(f)
-					if s0 {{$op.Name}} s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					_, s1 := v1(f)
-					dest(f).SetBool(s0 {{$op.Name}} s1)
-					return tnext
-				}
-			}
-		}
-	default:
-		switch {
-		case c0.rval.IsValid():
-			i0 := c0.rval.Interface()
-			v1 := genValue(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i1 := v1(f).Interface()
-					if i0 {{$op.Name}} i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i1 := v1(f).Interface()
-					dest(f).SetBool(i0 {{$op.Name}} i1)
-					return tnext
-				}
-			}
-		case c1.rval.IsValid():
-			i1 := c1.rval.Interface()
-			v0 := genValue(c0)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					if i0 {{$op.Name}} i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					dest(f).SetBool(i0 {{$op.Name}} i1)
-					return tnext
-				}
-			}
-		default:
-			v0 := genValue(c0)
-			v1 := genValue(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					i1 := v1(f).Interface()
-					if i0 {{$op.Name}} i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					i1 := v1(f).Interface()
-					dest(f).SetBool(i0 {{$op.Name}} i1)
-					return tnext
-				}
-			}
-		}
-	{{- end}}
 	case isFloat(t0) || isFloat(t1):
 		switch {
 		case c0.rval.IsValid():
@@ -781,6 +663,148 @@ func {{$name}}(n *node) {
 				}
 			}
 		}
+	{{- if $op.Complex}}
+	case isComplex(t0) || isComplex(t1):
+		switch {
+		case c0.rval.IsValid():
+			s0 := vComplex(c0.rval)
+			v1 := genComplex(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s1 := v1(f)
+					if s0 {{$op.Name}} s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				n.exec = func(f *frame) bltn {
+					s1 := v1(f)
+					dest(f).SetBool(s0 {{$op.Name}} s1)
+					return tnext
+				}
+			}
+		case c1.rval.IsValid():
+			s1 := vComplex(c1.rval)
+			v0 := genComplex(c0)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					if s0 {{$op.Name}} s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					dest(f).SetBool(s0 {{$op.Name}} s1)
+					return tnext
+				}
+			}
+		default:
+			v0 := genComplex(n.child[0])
+			v1 := genComplex(n.child[1])
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					s1 := v1(f)
+					if s0 {{$op.Name}} s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					s1 := v1(f)
+					dest(f).SetBool(s0 {{$op.Name}} s1)
+					return tnext
+				}
+			}
+		}
+	default:
+		switch {
+		case c0.rval.IsValid():
+			i0 := c0.rval.Interface()
+			v1 := genValue(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i1 := v1(f).Interface()
+					if i0 {{$op.Name}} i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i1 := v1(f).Interface()
+					dest(f).SetBool(i0 {{$op.Name}} i1)
+					return tnext
+				}
+			}
+		case c1.rval.IsValid():
+			i1 := c1.rval.Interface()
+			v0 := genValue(c0)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					if i0 {{$op.Name}} i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					dest(f).SetBool(i0 {{$op.Name}} i1)
+					return tnext
+				}
+			}
+		default:
+			v0 := genValue(c0)
+			v1 := genValue(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					i1 := v1(f).Interface()
+					if i0 {{$op.Name}} i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					i1 := v1(f).Interface()
+					dest(f).SetBool(i0 {{$op.Name}} i1)
+					return tnext
+				}
+			}
+		}
+	{{- end}}
 	}
 }
 {{end}}
@@ -793,6 +817,7 @@ type Op struct {
 	Float   bool   // true if operator applies to float
 	Complex bool   // true if operator applies to complex
 	Shift   bool   // true if operator is a shift operation
+	Bool    bool   // true if operator applies to bool
 }
 
 func main() {
@@ -805,17 +830,17 @@ func main() {
 	b := &bytes.Buffer{}
 	data := map[string]interface{}{
 		"Arithmetic": map[string]Op{
-			"add":    {"+", true, true, true, false},
-			"sub":    {"-", false, true, true, false},
-			"mul":    {"*", false, true, true, false},
-			"quo":    {"/", false, true, true, false},
-			"rem":    {"%", false, false, false, false},
-			"shl":    {"<<", false, false, false, true},
-			"shr":    {">>", false, false, false, true},
-			"and":    {"&", false, false, false, false},
-			"or":     {"|", false, false, false, false},
-			"xor":    {"^", false, false, false, false},
-			"andNot": {"&^", false, false, false, false},
+			"add":    {"+", true, true, true, false, false},
+			"sub":    {"-", false, true, true, false, false},
+			"mul":    {"*", false, true, true, false, false},
+			"quo":    {"/", false, true, true, false, false},
+			"rem":    {"%", false, false, false, false, false},
+			"shl":    {"<<", false, false, false, true, false},
+			"shr":    {">>", false, false, false, true, false},
+			"and":    {"&", false, false, false, false, false},
+			"or":     {"|", false, false, false, false, false},
+			"xor":    {"^", false, false, false, false, false},
+			"andNot": {"&^", false, false, false, false, false},
 		},
 		"IncDec": map[string]Op{
 			"inc": {Name: "+"},
@@ -829,6 +854,12 @@ func main() {
 			"lowerEqual":   {Name: "<=", Complex: false},
 			"notEqual":     {Name: "!=", Complex: true},
 		},
+		"Unary": map[string]Op{
+			"not":    {Name: "!", Float: false, Bool: true},
+			"neg":    {Name: "-", Float: true, Bool: false},
+			"pos":    {Name: "+", Float: true, Bool: false},
+			"bitNot": {Name: "^", Float: false, Bool: false},
+		},
 	}
 	if err = parse.Execute(b, data); err != nil {
 		log.Fatal(err)

interp/ast.go

@@ -6,8 +6,10 @@ import (
 	"go/parser"
 	"go/scanner"
 	"go/token"
+	"math"
 	"reflect"
 	"strconv"
+	"sync/atomic"
 )
 
 // nkind defines the kind of AST, i.e. the grammar category
@@ -197,6 +199,7 @@ const (
 	aAndAssign
 	aAndNot
 	aAndNotAssign
+	aBitNot
 	aCall
 	aCase
 	aCompositeLit
@@ -215,11 +218,12 @@ const (
 	aMethod
 	aMul
 	aMulAssign
-	aNegate
+	aNeg
 	aNot
 	aNotEqual
 	aOr
 	aOrAssign
+	aPos
 	aQuo
 	aQuoAssign
 	aRange
@@ -253,6 +257,7 @@ var actions = [...]string{
 	aAndAssign:    "&=",
 	aAndNot:       "&^",
 	aAndNotAssign: "&^=",
+	aBitNot:       "^",
 	aCall:         "call",
 	aCase:         "case",
 	aCompositeLit: "compositeLit",
@@ -269,11 +274,12 @@ var actions = [...]string{
 	aMethod:       "Method",
 	aMul:          "*",
 	aMulAssign:    "*=",
-	aNegate:       "-",
+	aNeg:          "-",
 	aNot:          "!",
 	aNotEqual:     "!=",
 	aOr:           "|",
 	aOrAssign:     "|=",
+	aPos:          "+",
 	aQuo:          "/",
 	aQuoAssign:    "/=",
 	aRange:        "range",
@@ -320,6 +326,7 @@ func (interp *Interpreter) firstToken(src string) token.Token {
 func (interp *Interpreter) ast(src, name string) (string, *node, error) {
 	inRepl := name == ""
 	var inFunc bool
+	var mode parser.Mode
 
 	// Allow incremental parsing of declarations or statements, by inserting
 	// them in a pseudo file package or function. Those statements or
@@ -334,26 +341,30 @@ func (interp *Interpreter) ast(src, name string) (string, *node, error) {
 			inFunc = true
 			src = "package main; func main() {" + src + "}"
 		}
+		// Parse comments in REPL mode, to allow tag setting
+		mode |= parser.ParseComments
 	}
 
-	if ok, err := interp.buildOk(interp.context, name, src); !ok || err != nil {
+	if ok, err := interp.buildOk(&interp.context, name, src); !ok || err != nil {
 		return "", nil, err // skip source not matching build constraints
 	}
 
-	f, err := parser.ParseFile(interp.fset, name, src, 0)
+	f, err := parser.ParseFile(interp.fset, name, src, mode)
 	if err != nil {
 		return "", nil, err
 	}
 
+	setYaegiTags(&interp.context, f.Comments)
+
 	var root *node
 	var anc astNode
 	var st nodestack
 	var pkgName string
 
 	addChild := func(root **node, anc astNode, pos token.Pos, kind nkind, act action) *node {
-		interp.nindex++
 		var i interface{}
-		n := &node{anc: anc.node, interp: interp, index: interp.nindex, pos: pos, kind: kind, action: act, val: &i, gen: builtin[act]}
+		nindex := atomic.AddInt64(&interp.nindex, 1)
+		n := &node{anc: anc.node, interp: interp, index: nindex, pos: pos, kind: kind, action: act, val: &i, gen: builtin[act]}
 		n.start = n
 		if anc.node == nil {
 			*root = n
@@ -364,15 +375,15 @@ func (interp *Interpreter) ast(src, name string) (string, *node, error) {
 				if len(ancAst.List)+len(ancAst.Body) == len(anc.node.child) {
 					// All case clause children are collected.
 					// Split children in condition and body nodes to desambiguify the AST.
-					interp.nindex++
-					body := &node{anc: anc.node, interp: interp, index: interp.nindex, pos: pos, kind: caseBody, action: aNop, val: &i, gen: nop}
+					nindex = atomic.AddInt64(&interp.nindex, 1)
+					body := &node{anc: anc.node, interp: interp, index: nindex, pos: pos, kind: caseBody, action: aNop, val: &i, gen: nop}
 
 					if ts := anc.node.anc.anc; ts.kind == typeSwitch && ts.child[1].action == aAssign {
 						// In type switch clause, if a switch guard is assigned, duplicate the switch guard symbol
 						// in each clause body, so a different guard type can be set in each clause
 						name := ts.child[1].child[0].ident
-						interp.nindex++
-						gn := &node{anc: body, interp: interp, ident: name, index: interp.nindex, pos: pos, kind: identExpr, action: aNop, val: &i, gen: nop}
+						nindex = atomic.AddInt64(&interp.nindex, 1)
+						gn := &node{anc: body, interp: interp, ident: name, index: nindex, pos: pos, kind: identExpr, action: aNop, val: &i, gen: nop}
 						body.child = append(body.child, gn)
 					}
 
@@ -459,7 +470,11 @@ func (interp *Interpreter) ast(src, name string) (string, *node, error) {
 				n.rval = reflect.ValueOf(v)
 			case token.FLOAT:
 				v, _ := strconv.ParseFloat(a.Value, 64)
-				n.rval = reflect.ValueOf(v)
+				if math.Trunc(v) == v {
+					n.rval = reflect.ValueOf(int(v))
+				} else {
+					n.rval = reflect.ValueOf(v)
+				}
 			case token.IMAG:
 				v, _ := strconv.ParseFloat(a.Value[:len(a.Value)-1], 64)
 				n.rval = reflect.ValueOf(complex(0, v))
@@ -548,6 +563,9 @@ func (interp *Interpreter) ast(src, name string) (string, *node, error) {
 		case *ast.CommClause:
 			st.push(addChild(&root, anc, pos, commClause, aNop), nod)
 
+		case *ast.CommentGroup:
+			return false
+
 		case *ast.CompositeLit:
 			st.push(addChild(&root, anc, pos, compositeLitExpr, aCompositeLit), nod)
 
@@ -757,6 +775,8 @@ func (interp *Interpreter) ast(src, name string) (string, *node, error) {
 			var kind = unaryExpr
 			var act action
 			switch a.Op {
+			case token.ADD:
+				act = aPos
 			case token.AND:
 				kind = addressExpr
 				act = aAddr
@@ -765,7 +785,9 @@ func (interp *Interpreter) ast(src, name string) (string, *node, error) {
 			case token.NOT:
 				act = aNot
 			case token.SUB:
-				act = aNegate
+				act = aNeg
+			case token.XOR:
+				act = aBitNot
 			}
 			st.push(addChild(&root, anc, pos, kind, act), nod)
 
@@ -839,9 +861,9 @@ func (s *nodestack) top() astNode {
 
 // dup returns a duplicated node subtree
 func (interp *Interpreter) dup(nod, anc *node) *node {
-	interp.nindex++
+	nindex := atomic.AddInt64(&interp.nindex, 1)
 	n := *nod
-	n.index = interp.nindex
+	n.index = nindex
 	n.anc = anc
 	n.start = &n
 	n.pos = anc.pos

interp/build.go

@@ -1,6 +1,7 @@
 package interp
 
 import (
+	"go/ast"
 	"go/build"
 	"go/parser"
 	"path"
@@ -11,7 +12,7 @@ import (
 // buildOk returns true if a file or script matches build constraints
 // as specified in https://golang.org/pkg/go/build/#hdr-Build_Constraints.
 // An error from parser is returned as well.
-func (interp *Interpreter) buildOk(ctx build.Context, name, src string) (bool, error) {
+func (interp *Interpreter) buildOk(ctx *build.Context, name, src string) (bool, error) {
 	// Extract comments before the first clause
 	f, err := parser.ParseFile(interp.fset, name, src, parser.PackageClauseOnly|parser.ParseComments)
 	if err != nil {
@@ -25,12 +26,13 @@ func (interp *Interpreter) buildOk(ctx build.Context, name, src string) (bool, e
 			}
 		}
 	}
+	setYaegiTags(ctx, f.Comments)
 	return true, nil
 }
 
 // buildLineOk returns true if line is not a build constraint or
 // if build constraint is satisfied
-func buildLineOk(ctx build.Context, line string) (ok bool) {
+func buildLineOk(ctx *build.Context, line string) (ok bool) {
 	if len(line) < 7 || line[:7] != "+build " {
 		return true
 	}
@@ -45,7 +47,7 @@ func buildLineOk(ctx build.Context, line string) (ok bool) {
 }
 
 // buildOptionOk return true if all comma separated tags match, false otherwise
-func buildOptionOk(ctx build.Context, tag string) bool {
+func buildOptionOk(ctx *build.Context, tag string) bool {
 	// in option, evaluate the AND of individual tags
 	for _, t := range strings.Split(tag, ",") {
 		if !buildTagOk(ctx, t) {
@@ -57,7 +59,7 @@ func buildOptionOk(ctx build.Context, tag string) bool {
 
 // buildTagOk returns true if a build tag matches, false otherwise
 // if first character is !, result is negated
-func buildTagOk(ctx build.Context, s string) (r bool) {
+func buildTagOk(ctx *build.Context, s string) (r bool) {
 	not := s[0] == '!'
 	if not {
 		s = s[1:]
@@ -82,6 +84,25 @@ func buildTagOk(ctx build.Context, s string) (r bool) {
 	return
 }
 
+// setYaegiTags scans a comment group for "yaegi:tags tag1 tag2 ..." lines
+// and adds the corresponding tags to the interpreter build tags.
+func setYaegiTags(ctx *build.Context, comments []*ast.CommentGroup) {
+	for _, g := range comments {
+		for _, line := range strings.Split(strings.TrimSpace(g.Text()), "\n") {
+			if len(line) < 11 || line[:11] != "yaegi:tags " {
+				continue
+			}
+
+			tags := strings.Split(strings.TrimSpace(line[10:]), " ")
+			for _, tag := range tags {
+				if !contains(ctx.BuildTags, tag) {
+					ctx.BuildTags = append(ctx.BuildTags, tag)
+				}
+			}
+		}
+	}
+}
+
 func contains(tags []string, tag string) bool {
 	for _, t := range tags {
 		if t == tag {
@@ -92,7 +113,7 @@ func contains(tags []string, tag string) bool {
 }
 
 // goMinorVersion returns the go minor version number
-func goMinorVersion(ctx build.Context) int {
+func goMinorVersion(ctx *build.Context) int {
 	current := ctx.ReleaseTags[len(ctx.ReleaseTags)-1]
 
 	v := strings.Split(current, ".")
@@ -108,7 +129,7 @@ func goMinorVersion(ctx build.Context) int {
 }
 
 // skipFile returns true if file should be skipped
-func skipFile(ctx build.Context, p string) bool {
+func skipFile(ctx *build.Context, p string) bool {
 	if !strings.HasSuffix(p, ".go") {
 		return true
 	}

interp/build_test.go

@@ -44,7 +44,7 @@ func TestBuildTag(t *testing.T) {
 		test := test
 		src := test.src + "\npackage x"
 		t.Run(test.src, func(t *testing.T) {
-			if r, _ := i.buildOk(ctx, "", src); r != test.res {
+			if r, _ := i.buildOk(&ctx, "", src); r != test.res {
 				t.Errorf("got %v, want %v", r, test.res)
 			}
 		})
@@ -74,7 +74,7 @@ func TestBuildFile(t *testing.T) {
 	for _, test := range tests {
 		test := test
 		t.Run(test.src, func(t *testing.T) {
-			if r := skipFile(ctx, test.src); r != test.res {
+			if r := skipFile(&ctx, test.src); r != test.res {
 				t.Errorf("got %v, want %v", r, test.res)
 			}
 		})
@@ -106,7 +106,7 @@ func Test_goMinorVersion(t *testing.T) {
 	for _, test := range tests {
 		test := test
 		t.Run(test.desc, func(t *testing.T) {
-			minor := goMinorVersion(test.context)
+			minor := goMinorVersion(&test.context)
 
 			if minor != test.expected {
 				t.Errorf("got %v, want %v", minor, test.expected)

interp/cfg.go

@@ -4,8 +4,8 @@ import (
 	"fmt"
 	"log"
 	"math"
-	"path"
 	"reflect"
+	"regexp"
 	"unicode"
 )
 
@@ -24,15 +24,26 @@ var constOp = map[action]func(*node){
 	aShr:    shrConst,
 	aAndNot: andNotConst,
 	aXor:    xorConst,
+	aNot:    notConst,
+	aBitNot: bitNotConst,
+	aNeg:    negConst,
+	aPos:    posConst,
 }
 
+var constBltn = map[string]func(*node){
+	"complex": complexConst,
+	"imag":    imagConst,
+	"real":    realConst,
+}
+
+var identifier = regexp.MustCompile(`([\pL_][\pL_\d]*)$`)
+
 // cfg generates a control flow graph (CFG) from AST (wiring successors in AST)
 // and pre-compute frame sizes and indexes for all un-named (temporary) and named
 // variables. A list of nodes of init functions is returned.
 // Following this pass, the CFG is ready to run
-func (interp *Interpreter) cfg(root *node) ([]*node, error) {
-	sc, pkgName := interp.initScopePkg(root)
-	var loop, loopRestart *node
+func (interp *Interpreter) cfg(root *node, pkgID string) ([]*node, error) {
+	sc := interp.initScopePkg(pkgID)
 	var initNodes []*node
 	var iotaValue int
 	var err error
@@ -77,14 +88,18 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 							ktyp = &itype{cat: valueT, rtype: typ.Key()}
 							vtyp = &itype{cat: valueT, rtype: typ.Elem()}
 						case reflect.String:
+							sc.add(sc.getType("int")) // Add a dummy type to store array shallow copy for range
 							ktyp = sc.getType("int")
 							vtyp = sc.getType("rune")
 						case reflect.Array, reflect.Slice:
+							sc.add(sc.getType("int")) // Add a dummy type to store array shallow copy for range
 							ktyp = sc.getType("int")
 							vtyp = &itype{cat: valueT, rtype: typ.Elem()}
 						}
 					case mapT:
 						n.anc.gen = rangeMap
+						ityp := &itype{cat: valueT, rtype: reflect.TypeOf((*reflect.MapIter)(nil))}
+						sc.add(ityp)
 						ktyp = o.typ.key
 						vtyp = o.typ.val
 					case ptrT:
@@ -96,9 +111,11 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 							vtyp = vtyp.val
 						}
 					case stringT:
+						sc.add(sc.getType("int")) // Add a dummy type to store array shallow copy for range
 						ktyp = sc.getType("int")
 						vtyp = sc.getType("rune")
 					case arrayT, variadicT:
+						sc.add(sc.getType("int")) // Add a dummy type to store array shallow copy for range
 						ktyp = sc.getType("int")
 						vtyp = o.typ.val
 					}
@@ -158,19 +175,21 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				var typ *itype
 				if len(n.child) == 2 {
 					// 1 type in clause: define the var with this type in the case clause scope
-					switch sym, _, ok := sc.lookup(n.child[0].ident); {
-					case ok && sym.kind == typeSym:
-						typ = sym.typ
+					switch {
 					case n.child[0].ident == "nil":
 						typ = sc.getType("interface{}")
-					default:
+					case !n.child[0].isType(sc):
 						err = n.cfgErrorf("%s is not a type", n.child[0].ident)
-						return false
+					default:
+						typ, err = nodeType(interp, sc, n.child[0])
 					}
 				} else {
 					// define the var with the type in the switch guard expression
 					typ = sn.child[1].child[1].child[0].typ
 				}
+				if err != nil {
+					return false
+				}
 				nod := n.lastChild().child[0]
 				index := sc.add(typ)
 				sc.sym[nod.ident] = &symbol{index: index, kind: varSym, typ: typ}
@@ -216,12 +235,12 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			}
 
 		case forStmt0, forRangeStmt:
-			loop, loopRestart = n, n.child[0]
 			sc = sc.pushBloc()
+			sc.loop, sc.loopRestart = n, n.child[0]
 
 		case forStmt1, forStmt2, forStmt3, forStmt3a, forStmt4:
-			loop, loopRestart = n, n.lastChild()
 			sc = sc.pushBloc()
+			sc.loop, sc.loopRestart = n, n.lastChild()
 
 		case funcLit:
 			n.typ = nil // to force nodeType to recompute the type
@@ -258,13 +277,16 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			if len(n.child[0].child) > 0 {
 				// define receiver symbol
 				var typ *itype
-				recvName := n.child[0].child[0].child[0].ident
-				recvTypeNode := n.child[0].child[0].lastChild()
+				fr := n.child[0].child[0]
+				recvTypeNode := fr.lastChild()
 				if typ, err = nodeType(interp, sc, recvTypeNode); err != nil {
 					return false
 				}
 				recvTypeNode.typ = typ
-				sc.sym[recvName] = &symbol{index: sc.add(typ), kind: varSym, typ: typ}
+				index := sc.add(typ)
+				if len(fr.child) > 1 {
+					sc.sym[fr.child[0].ident] = &symbol{index: index, kind: varSym, typ: typ}
+				}
 			}
 			for _, c := range n.child[2].child[0].child {
 				// define input parameter symbols
@@ -290,7 +312,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				c[i], c[l] = c[l], c[i]
 			}
 			sc = sc.pushBloc()
-			loop = n
+			sc.loop = n
 
 		case importSpec:
 			var name, ipath string
@@ -299,7 +321,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				name = n.child[0].ident
 			} else {
 				ipath = n.child[0].rval.String()
-				name = path.Base(ipath)
+				name = identifier.FindString(ipath)
 			}
 			if interp.binPkg[ipath] != nil && name != "." {
 				sc.sym[name] = &symbol{kind: pkgSym, typ: &itype{cat: binPkgT, path: ipath}}
@@ -388,14 +410,18 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 						if src.typ, err = nodeType(interp, sc, src); err != nil {
 							return
 						}
-						dest.typ = src.typ
+						if src.typ.isBinMethod {
+							dest.typ = &itype{cat: valueT, rtype: src.typ.methodCallType()}
+						} else {
+							dest.typ = src.typ
+						}
 					}
 					if dest.typ.sizedef {
-						dest.typ.size = compositeArrayLen(src)
+						dest.typ.size = arrayTypeLen(src)
 						dest.typ.rtype = nil
 					}
 					if sc.global {
-						// Do not overload existings symbols (defined in GTA) in global scope
+						// Do not overload existing symbols (defined in GTA) in global scope
 						sym, _, _ = sc.lookup(dest.ident)
 					} else {
 						sym = &symbol{index: sc.add(dest.typ), kind: varSym, typ: dest.typ}
@@ -441,11 +467,14 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 					n.gen = nop
 					src.level = level
 					src.findex = dest.findex
+					if src.typ.untyped && !dest.typ.untyped {
+						src.typ = dest.typ
+					}
 				case n.action == aAssign && src.action == aRecv:
 					// Assign by reading from a receiving channel
 					n.gen = nop
 					src.findex = dest.findex // Set recv address to LHS
-					dest.typ = src.typ.val
+					dest.typ = src.typ
 				case n.action == aAssign && src.action == aCompositeLit:
 					n.gen = nop
 					src.findex = dest.findex
@@ -454,6 +483,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 					// TODO: perform constant folding and propagation here
 					switch {
 					case dest.typ.cat == interfaceT:
+					case isComplex(dest.typ.TypeOf()):
 						// value set in genValue
 					case !src.rval.IsValid():
 						// Assign to nil
@@ -498,7 +528,11 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				n.child[l].gen = getIndexMap2
 				n.gen = nop
 			case typeAssertExpr:
-				n.child[l].gen = typeAssert2
+				if n.child[0].ident == "_" {
+					n.child[l].gen = typeAssertStatus
+				} else {
+					n.child[l].gen = typeAssert2
+				}
 				n.gen = nop
 			case unaryExpr:
 				if n.child[l].action == aRecv {
@@ -522,7 +556,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			t0, t1 := c0.typ.TypeOf(), c1.typ.TypeOf()
 			// Shift operator type is inherited from first parameter only
 			// All other binary operators require both parameter types to be the same
-			if !isShiftNode(n) && !c0.typ.untyped && !c1.typ.untyped && c0.typ.id() != c1.typ.id() {
+			if !isShiftNode(n) && !c0.typ.untyped && !c1.typ.untyped && !c0.typ.equals(c1.typ) {
 				err = n.cfgErrorf("mismatched types %s and %s", c0.typ.id(), c1.typ.id())
 				break
 			}
@@ -575,8 +609,6 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				constOp[n.action](n)
 			}
 			switch {
-			//case n.typ != nil && n.typ.cat == BoolT && isAncBranch(n):
-			//	n.findex = -1
 			case n.rval.IsValid():
 				n.gen = nop
 				n.findex = -1
@@ -611,7 +643,11 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			case stringT:
 				n.typ = sc.getType("byte")
 			case valueT:
-				n.typ = &itype{cat: valueT, rtype: t.rtype.Elem()}
+				if t.rtype.Kind() == reflect.String {
+					n.typ = sc.getType("byte")
+				} else {
+					n.typ = &itype{cat: valueT, rtype: t.rtype.Elem()}
+				}
 			default:
 				n.typ = t.val
 			}
@@ -665,14 +701,14 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			if len(n.child) > 0 {
 				gotoLabel(n.sym)
 			} else {
-				n.tnext = loop
+				n.tnext = sc.loop
 			}
 
 		case continueStmt:
 			if len(n.child) > 0 {
 				gotoLabel(n.sym)
 			} else {
-				n.tnext = loopRestart
+				n.tnext = sc.loopRestart
 			}
 
 		case gotoStmt:
@@ -698,6 +734,10 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				} else {
 					n.findex = sc.add(n.typ)
 				}
+				if op, ok := constBltn[n.child[0].ident]; ok && n.anc.action != aAssign {
+					op(n) // pre-compute non-assigned constant builtin calls
+				}
+
 			case n.child[0].isType(sc):
 				// Type conversion expression
 				if isInt(n.child[0].typ.TypeOf()) && n.child[1].kind == basicLit && isFloat(n.child[1].typ.TypeOf()) {
@@ -792,36 +832,41 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			body := n.child[0]
 			n.start = body.start
 			body.tnext = n.start
-			loop, loopRestart = nil, nil
 			sc = sc.pop()
 
 		case forStmt1: // for cond {}
 			cond, body := n.child[0], n.child[1]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as for condition")
+			}
 			n.start = cond.start
 			cond.tnext = body.start
 			cond.fnext = n
 			body.tnext = cond.start
-			loop, loopRestart = nil, nil
 			sc = sc.pop()
 
 		case forStmt2: // for init; cond; {}
 			init, cond, body := n.child[0], n.child[1], n.child[2]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as for condition")
+			}
 			n.start = init.start
 			init.tnext = cond.start
 			cond.tnext = body.start
 			cond.fnext = n
 			body.tnext = cond.start
-			loop, loopRestart = nil, nil
 			sc = sc.pop()
 
 		case forStmt3: // for ; cond; post {}
 			cond, post, body := n.child[0], n.child[1], n.child[2]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as for condition")
+			}
 			n.start = cond.start
 			cond.tnext = body.start
 			cond.fnext = n
 			body.tnext = post.start
 			post.tnext = cond.start
-			loop, loopRestart = nil, nil
 			sc = sc.pop()
 
 		case forStmt3a: // for int; ; post {}
@@ -830,22 +875,22 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			init.tnext = body.start
 			body.tnext = post.start
 			post.tnext = body.start
-			loop, loopRestart = nil, nil
 			sc = sc.pop()
 
 		case forStmt4: // for init; cond; post {}
 			init, cond, post, body := n.child[0], n.child[1], n.child[2], n.child[3]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as for condition")
+			}
 			n.start = init.start
 			init.tnext = cond.start
 			cond.tnext = body.start
 			cond.fnext = n
 			body.tnext = post.start
 			post.tnext = cond.start
-			loop, loopRestart = nil, nil
 			sc = sc.pop()
 
 		case forRangeStmt:
-			loop, loopRestart = nil, nil
 			n.start = n.child[0].start
 			n.child[0].fnext = n
 			sc = sc.pop()
@@ -856,15 +901,16 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			sc = sc.pop()
 			funcName := n.child[1].ident
 			if !isMethod(n) {
-				interp.scopes[pkgName].sym[funcName].index = -1 // to force value to n.val
-				interp.scopes[pkgName].sym[funcName].typ = n.typ
-				interp.scopes[pkgName].sym[funcName].kind = funcSym
-				interp.scopes[pkgName].sym[funcName].node = n
+				interp.scopes[pkgID].sym[funcName].index = -1 // to force value to n.val
+				interp.scopes[pkgID].sym[funcName].typ = n.typ
+				interp.scopes[pkgID].sym[funcName].kind = funcSym
+				interp.scopes[pkgID].sym[funcName].node = n
 			}
 
 		case funcLit:
 			n.types = sc.types
 			sc = sc.pop()
+			err = genRun(n)
 
 		case goStmt:
 			wireChild(n)
@@ -917,6 +963,9 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 
 		case ifStmt0: // if cond {}
 			cond, tbody := n.child[0], n.child[1]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as if condition")
+			}
 			n.start = cond.start
 			cond.tnext = tbody.start
 			cond.fnext = n
@@ -925,6 +974,9 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 
 		case ifStmt1: // if cond {} else {}
 			cond, tbody, fbody := n.child[0], n.child[1], n.child[2]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as if condition")
+			}
 			n.start = cond.start
 			cond.tnext = tbody.start
 			cond.fnext = fbody.start
@@ -934,6 +986,9 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 
 		case ifStmt2: // if init; cond {}
 			init, cond, tbody := n.child[0], n.child[1], n.child[2]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as if condition")
+			}
 			n.start = init.start
 			tbody.tnext = n
 			init.tnext = cond.start
@@ -943,6 +998,9 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 
 		case ifStmt3: // if init; cond {} else {}
 			init, cond, tbody, fbody := n.child[0], n.child[1], n.child[2], n.child[3]
+			if !isBool(cond.typ) {
+				err = cond.cfgErrorf("non-bool used as if condition")
+			}
 			n.start = init.start
 			init.tnext = cond.start
 			cond.tnext = tbody.start
@@ -961,6 +1019,9 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			n.child[1].tnext = n
 			n.typ = n.child[0].typ
 			n.findex = sc.add(n.typ)
+			if n.start.action == aNop {
+				n.start.gen = branch
+			}
 
 		case lorExpr:
 			n.start = n.child[0].start
@@ -969,6 +1030,9 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 			n.child[1].tnext = n
 			n.typ = n.child[0].typ
 			n.findex = sc.add(n.typ)
+			if n.start.action == aNop {
+				n.start.gen = branch
+			}
 
 		case parenExpr:
 			wireChild(n)
@@ -1008,10 +1072,15 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 					// nil: Set node value to zero of return type
 					f := sc.def
 					var typ *itype
-					if typ, err = nodeType(interp, sc, f.child[2].child[1].child[i].lastChild()); err != nil {
+					if typ, err = nodeType(interp, sc, f.child[2].child[1].fieldType(i)); err != nil {
 						return
 					}
-					c.rval = reflect.New(typ.TypeOf()).Elem()
+					if typ.cat == funcT {
+						// Wrap the typed nil value in a node, as per other interpreter functions
+						c.rval = reflect.ValueOf(&node{kind: basicLit, rval: reflect.New(typ.TypeOf()).Elem()})
+					} else {
+						c.rval = reflect.New(typ.TypeOf()).Elem()
+					}
 				}
 			}
 
@@ -1032,7 +1101,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 					n.val = method.Index
 					n.gen = getIndexBinMethod
 					n.recv = &receiver{node: n.child[0]}
-					n.typ = &itype{cat: valueT, rtype: method.Type}
+					n.typ = &itype{cat: valueT, rtype: method.Type, isBinMethod: true}
 				case n.typ.rtype.Kind() == reflect.Ptr:
 					if field, ok := n.typ.rtype.Elem().FieldByName(n.child[1].ident); ok {
 						n.typ = &itype{cat: valueT, rtype: field.Type}
@@ -1077,7 +1146,6 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 					n.typ = &itype{cat: valueT, rtype: field.Type}
 					n.val = field.Index
 					n.gen = getPtrIndexSeq
-
 				} else {
 					err = n.cfgErrorf("undefined selector: %s", n.child[1].ident)
 				}
@@ -1091,7 +1159,7 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 						n.typ = &itype{cat: valueT, rtype: s.Type().Elem()}
 					} else {
 						n.kind = rvalueExpr
-						n.typ = &itype{cat: valueT, rtype: s.Type()}
+						n.typ = &itype{cat: valueT, rtype: s.Type(), untyped: isValueUntyped(s)}
 						n.rval = s
 					}
 					n.gen = nop
@@ -1248,7 +1316,6 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				n.start = sbn.start
 			}
 			sc = sc.pop()
-			loop = nil
 
 		case switchIfStmt: // like an if-else chain
 			sbn := n.lastChild() // switch block node
@@ -1285,13 +1352,14 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				n.start = sbn.start
 			}
 			sc = sc.pop()
-			loop = nil
 
 		case typeAssertExpr:
 			if len(n.child) > 1 {
 				wireChild(n)
 				if n.child[1].typ == nil {
-					n.child[1].typ = sc.getType(n.child[1].ident)
+					if n.child[1].typ, err = nodeType(interp, sc, n.child[1]); err != nil {
+						return
+					}
 				}
 				if n.anc.action != aAssignX {
 					n.typ = n.child[1].typ
@@ -1303,26 +1371,68 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 
 		case sliceExpr:
 			wireChild(n)
-			ctyp := n.child[0].typ
-			if ctyp.cat == ptrT {
-				ctyp = ctyp.val
-			}
-			if ctyp.size != 0 {
-				// Create a slice type from an array type
-				n.typ = &itype{}
-				*n.typ = *ctyp
-				n.typ.size = 0
-				n.typ.rtype = nil
-			} else {
-				n.typ = ctyp
+			if n.typ, err = nodeType(interp, sc, n); err != nil {
+				return
 			}
 			n.findex = sc.add(n.typ)
 
 		case unaryExpr:
 			wireChild(n)
 			n.typ = n.child[0].typ
+			switch n.action {
+			case aRecv:
+				// Channel receive operation: set type to the channel data type
+				if n.typ.cat == valueT {
+					n.typ = &itype{cat: valueT, rtype: n.typ.rtype.Elem()}
+				} else {
+					n.typ = n.typ.val
+				}
+			case aBitNot:
+				if !isInt(n.typ.TypeOf()) {
+					err = n.cfgErrorf("illegal operand type for '^' operator")
+					return
+				}
+			case aNot:
+				if !isBool(n.typ) {
+					err = n.cfgErrorf("illegal operand type for '!' operator")
+					return
+				}
+			case aNeg, aPos:
+				if !isNumber(n.typ.TypeOf()) {
+					err = n.cfgErrorf("illegal operand type for '%v' operator", n.action)
+					return
+				}
+			}
 			// TODO: Optimisation: avoid allocation if boolean branch op (i.e. '!' in an 'if' expr)
-			n.findex = sc.add(n.typ)
+			if n.child[0].rval.IsValid() && constOp[n.action] != nil {
+				if n.typ == nil {
+					if n.typ, err = nodeType(interp, sc, n); err != nil {
+						return
+					}
+				}
+				n.typ.TypeOf() // init reflect type
+				constOp[n.action](n)
+			}
+			switch {
+			case n.rval.IsValid():
+				n.gen = nop
+				n.findex = -1
+			case n.anc.kind == assignStmt && n.anc.action == aAssign:
+				dest := n.anc.child[childPos(n)-n.anc.nright]
+				n.typ = dest.typ
+				n.findex = dest.findex
+			case n.anc.kind == returnStmt:
+				pos := childPos(n)
+				n.typ = sc.def.typ.ret[pos]
+				n.findex = pos
+			default:
+				if n.typ == nil {
+					if n.typ, err = nodeType(interp, sc, n); err != nil {
+						return
+					}
+				}
+				n.findex = sc.add(n.typ)
+			}
 
 		case valueSpec:
 			n.gen = reset
@@ -1333,8 +1443,14 @@ func (interp *Interpreter) cfg(root *node) ([]*node, error) {
 				}
 			}
 			for _, c := range n.child[:l] {
-				index := sc.add(n.typ)
-				sc.sym[c.ident] = &symbol{index: index, kind: varSym, typ: n.typ}
+				var index int
+				if sc.global {
+					// Global object allocation is already performed in GTA.
+					index = sc.sym[c.ident].index
+				} else {
+					index = sc.add(n.typ)
+					sc.sym[c.ident] = &symbol{index: index, kind: varSym, typ: n.typ}
+				}
 				c.typ = n.typ
 				c.findex = index
 			}
@@ -1351,9 +1467,9 @@ func compDefineX(sc *scope, n *node) error {
 	l := len(n.child) - 1
 	types := []*itype{}
 
-	switch n.child[l].kind {
+	switch src := n.child[l]; src.kind {
 	case callExpr:
-		funtype, err := nodeType(n.interp, sc, n.child[l].child[0])
+		funtype, err := nodeType(n.interp, sc, src.child[0])
 		if err != nil {
 			return err
 		}
@@ -1368,18 +1484,22 @@ func compDefineX(sc *scope, n *node) error {
 		n.gen = nop
 
 	case indexExpr:
-		types = append(types, n.child[l].child[0].typ.val, sc.getType("bool"))
+		types = append(types, src.typ, sc.getType("bool"))
 		n.child[l].gen = getIndexMap2
 		n.gen = nop
 
 	case typeAssertExpr:
+		if n.child[0].ident == "_" {
+			n.child[l].gen = typeAssertStatus
+		} else {
+			n.child[l].gen = typeAssert2
+		}
 		types = append(types, n.child[l].child[1].typ, sc.getType("bool"))
-		n.child[l].gen = typeAssert2
 		n.gen = nop
 
 	case unaryExpr:
 		if n.child[l].action == aRecv {
-			types = append(types, n.child[l].child[0].typ.val, sc.getType("bool"))
+			types = append(types, src.typ, sc.getType("bool"))
 			n.child[l].gen = recv2
 			n.gen = nop
 		}
@@ -1460,7 +1580,7 @@ func isBinType(v reflect.Value) bool { return v.IsValid() && v.Kind() == reflect
 // isType returns true if node refers to a type definition, false otherwise
 func (n *node) isType(sc *scope) bool {
 	switch n.kind {
-	case arrayType, chanType, funcType, mapType, structType, rtypeExpr:
+	case arrayType, chanType, funcType, interfaceType, mapType, structType, rtypeExpr:
 		return true
 	case parenExpr, starExpr:
 		if len(n.child) == 1 {
@@ -1468,7 +1588,7 @@ func (n *node) isType(sc *scope) bool {
 		}
 	case selectorExpr:
 		pkg, name := n.child[0].ident, n.child[1].ident
-		if sym, _, ok := sc.lookup(pkg); ok {
+		if sym, _, ok := sc.lookup(pkg); ok && sym.kind == pkgSym {
 			path := sym.typ.path
 			if p, ok := n.interp.binPkg[path]; ok && isBinType(p[name]) {
 				return true // Imported binary type
@@ -1538,7 +1658,7 @@ func (n *node) isInteger() bool {
 		if isFloat(t) {
 			// untyped float constant with null decimal part is ok
 			f := n.rval.Float()
-			if f == math.Round(f) {
+			if f == math.Trunc(f) {
 				n.rval = reflect.ValueOf(int(f))
 				n.typ.rtype = n.rval.Type()
 				return true
@@ -1565,7 +1685,7 @@ func (n *node) isNatural() bool {
 		if isFloat(t) {
 			// positive untyped float constant with null decimal part is ok
 			f := n.rval.Float()
-			if f == math.Round(f) && f >= 0 {
+			if f == math.Trunc(f) && f >= 0 {
 				n.rval = reflect.ValueOf(uint(f))
 				n.typ.rtype = n.rval.Type()
 				return true
@@ -1575,6 +1695,29 @@ func (n *node) isNatural() bool {
 	return false
 }
 
+// fieldType returns the nth parameter field node (type) of a fieldList node
+func (n *node) fieldType(m int) *node {
+	k := 0
+	l := len(n.child)
+	for i := 0; i < l; i++ {
+		cl := len(n.child[i].child)
+		if cl < 2 {
+			if k == m {
+				return n.child[i].lastChild()
+			}
+			k++
+			continue
+		}
+		for j := 0; j < cl-1; j++ {
+			if k == m {
+				return n.child[i].lastChild()
+			}
+			k++
+		}
+	}
+	return nil
+}
+
 // lastChild returns the last child of a node
 func (n *node) lastChild() *node { return n.child[len(n.child)-1] }
 
@@ -1582,7 +1725,8 @@ func isKey(n *node) bool {
 	return n.anc.kind == fileStmt ||
 		(n.anc.kind == selectorExpr && n.anc.child[0] != n) ||
 		(n.anc.kind == funcDecl && isMethod(n.anc)) ||
-		(n.anc.kind == keyValueExpr && isStruct(n.anc.typ) && n.anc.child[0] == n)
+		(n.anc.kind == keyValueExpr && isStruct(n.anc.typ) && n.anc.child[0] == n) ||
+		(n.anc.kind == fieldExpr && len(n.anc.child) > 1 && n.anc.child[0] == n)
 }
 
 // isNewDefine returns true if node refers to a new definition
@@ -1649,13 +1793,6 @@ func getExec(n *node) bltn {
 	return n.exec
 }
 
-func fileNode(n *node) *node {
-	if n == nil || n.kind == fileStmt {
-		return n
-	}
-	return fileNode(n.anc)
-}
-
 // setExec recursively sets the node exec builtin function by walking the CFG
 // from the entry point (first node to exec).
 func setExec(n *node) {
@@ -1735,13 +1872,20 @@ func compositeGenerator(n *node) (gen bltnGenerator) {
 	return
 }
 
-// compositeArrayLen return the litteral array length, computed from definition
-func compositeArrayLen(n *node) int {
+// arrayTypeLen returns the node's array length. If the expression is an
+// array variable it is determined from the value's type, otherwise it is
+// computed from the source definition.
+func arrayTypeLen(n *node) int {
+	if n.typ != nil && n.typ.sizedef {
+		return n.typ.size
+	}
 	max := -1
 	for i, c := range n.child[1:] {
 		r := i
 		if c.kind == keyValueExpr {
-			r = int(c.child[0].rval.Int())
+			if v := c.child[0].rval; v.IsValid() {
+				r = int(c.child[0].rval.Int())
+			}
 		}
 		if r > max {
 			max = r
@@ -1749,3 +1893,13 @@ func compositeArrayLen(n *node) int {
 	}
 	return max + 1
 }
+
+// isValueUntyped returns true if value is untyped
+func isValueUntyped(v reflect.Value) bool {
+	// Consider only constant values.
+	if v.CanSet() {
+		return false
+	}
+	t := v.Type()
+	return t.String() == t.Kind().String()
+}

interp/doc.go

@@ -1,10 +1,47 @@
 /*
-Package interp provides a complete Go interpreter
+Package interp provides a complete Go interpreter.
 
 For the Go language itself, refer to the official Go specification
 https://golang.org/ref/spec.
 
+Importing packages
+
+Packages can be imported in source or binary form, using the standard
+Go import statement. In source form, packages are searched first in the
+vendor directory, the preferred way to store source dependencies. If not
+found in vendor, sources modules will be searched in GOPATH. Go modules
+are not supported yet by yaegi.
+
+Binary form packages are compiled and linked with the interpreter
+executable, and exposed to scripts with the Use method. The goexports
+command can be used to generate package wrappers.
+
+Custom build tags
+
+Custom build tags allow to control which files in imported source
+packages are interpreted, in the same way as the "-tags" option of the
+"go build" command. Setting a custom build tag spans globally for all
+future imports of the session.
+
+A build tag is a line comment that begins
+
+	// yaegi:tags
+
+that lists the build constraints to be satisfied by the further
+imports of source packages.
+
+For example the following custom build tag
+
+	// yaegi:tags noasm
+
+Will ensure that an import of a package will exclude files containing
+
+	// +build !noasm
+
+And include files containing
+
+	// +build noasm
 */
 package interp
 
-// BUG(marc): Type checking is not implemented yet
+// BUG(marc): Type checking is not implemented yet.

interp/dot.go

@@ -38,7 +38,7 @@ func (n *node) astDot(out io.Writer, name string) {
 func (n *node) cfgDot(out io.Writer) {
 	fmt.Fprintf(out, "digraph cfg {\n")
 	n.Walk(nil, func(n *node) {
-		if n.kind == basicLit || n.kind == identExpr || n.tnext == nil {
+		if n.kind == basicLit || n.tnext == nil {
 			return
 		}
 		var label string

interp/gta.go

@@ -1,7 +1,6 @@
 package interp
 
 import (
-	"path"
 	"reflect"
 )
 
@@ -9,8 +8,8 @@ import (
 // variables and functions symbols at package level, prior to CFG.
 // All function bodies are skipped. GTA is necessary to handle out of
 // order declarations and multiple source files packages.
-func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
-	sc, _ := interp.initScopePkg(root)
+func (interp *Interpreter) gta(root *node, rpath, pkgID string) ([]*node, error) {
+	sc := interp.initScopePkg(pkgID)
 	var err error
 	var iotaValue int
 	var revisit []*node
@@ -31,6 +30,7 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 		case defineStmt:
 			var atyp *itype
 			if n.nleft+n.nright < len(n.child) {
+				// Type is declared explicitly in the assign expression.
 				if atyp, err = nodeType(interp, sc, n.child[n.nleft]); err != nil {
 					return false
 				}
@@ -52,7 +52,7 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 					val = src.rval
 				}
 				if typ.incomplete {
-					// Come back when type is known
+					// Come back when type is known.
 					revisit = append(revisit, n)
 					return false
 				}
@@ -60,6 +60,9 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 					err = n.cfgErrorf("use of untyped nil")
 					return false
 				}
+				if typ.isBinMethod {
+					typ = &itype{cat: valueT, rtype: typ.methodCallType(), isBinMethod: true}
+				}
 				sc.sym[dest.ident] = &symbol{kind: varSym, global: true, index: sc.add(typ), typ: typ, rval: val}
 				if n.anc.kind == constDecl {
 					sc.sym[dest.ident].kind = constSym
@@ -77,6 +80,11 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 				if n.typ, err = nodeType(interp, sc, n.child[l]); err != nil {
 					return false
 				}
+				if n.typ.incomplete {
+					// Come back when type is known.
+					revisit = append(revisit, n)
+					return false
+				}
 			}
 			for _, c := range n.child[:l] {
 				sc.sym[c.ident] = &symbol{index: sc.add(n.typ), kind: varSym, global: true, typ: n.typ}
@@ -126,7 +134,7 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 				name = n.child[0].ident
 			} else {
 				ipath = n.child[0].rval.String()
-				name = path.Base(ipath)
+				name = identifier.FindString(ipath)
 			}
 			// Try to import a binary package first, or a source package
 			if interp.binPkg[ipath] != nil {
@@ -143,7 +151,7 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 				default: // import symbols in package namespace
 					sc.sym[name] = &symbol{kind: pkgSym, typ: &itype{cat: binPkgT, path: ipath}}
 				}
-			} else if err = interp.importSrc(rpath, ipath, name); err == nil {
+			} else if err = interp.importSrc(rpath, ipath); err == nil {
 				sc.types = interp.universe.types
 				switch name {
 				case "_": // no import of symbols

interp/interp.go

@@ -2,13 +2,18 @@ package interp
 
 import (
 	"bufio"
+	"context"
 	"fmt"
 	"go/build"
 	"go/scanner"
 	"go/token"
+	"io"
 	"os"
+	"os/signal"
 	"reflect"
 	"strconv"
+	"sync"
+	"sync/atomic"
 )
 
 // Interpreter node structure for AST and CFG
@@ -20,7 +25,7 @@ type node struct {
 	fnext  *node          // false branch successor (CFG)
 	interp *Interpreter   // interpreter context
 	frame  *frame         // frame pointer used for closures only (TODO: suppress this)
-	index  int            // node index (dot display)
+	index  int64          // node index (dot display)
 	findex int            // index of value in frame or frame size (func def, type def)
 	level  int            // number of frame indirections to access value
 	nleft  int            // number of children in left part (assign)
@@ -48,10 +53,45 @@ type receiver struct {
 
 // frame contains values for the current execution level (a function context)
 type frame struct {
-	anc       *frame            // ancestor frame (global space)
-	data      []reflect.Value   // values
-	deferred  [][]reflect.Value // defer stack
-	recovered interface{}       // to handle panic recover
+	// id is an atomic counter used for cancellation, only access
+	// via newFrame/runid/setrunid/clone.
+	// Located at start of struct to ensure proper aligment.
+	id uint64
+
+	anc  *frame          // ancestor frame (global space)
+	data []reflect.Value // values
+
+	mutex     sync.RWMutex
+	deferred  [][]reflect.Value  // defer stack
+	recovered interface{}        // to handle panic recover
+	done      reflect.SelectCase // for cancellation of channel operations
+}
+
+func newFrame(anc *frame, len int, id uint64) *frame {
+	f := &frame{
+		anc:  anc,
+		data: make([]reflect.Value, len),
+		id:   id,
+	}
+	if anc != nil {
+		f.done = anc.done
+	}
+	return f
+}
+
+func (f *frame) runid() uint64      { return atomic.LoadUint64(&f.id) }
+func (f *frame) setrunid(id uint64) { atomic.StoreUint64(&f.id, id) }
+func (f *frame) clone() *frame {
+	f.mutex.RLock()
+	defer f.mutex.RUnlock()
+	return &frame{
+		anc:       f.anc,
+		data:      f.data,
+		deferred:  f.deferred,
+		recovered: f.recovered,
+		id:        f.runid(),
+		done:      f.done,
+	}
 }
 
 // Exports stores the map of binary packages per package path
@@ -62,24 +102,36 @@ type imports map[string]map[string]*symbol
 
 // opt stores interpreter options
 type opt struct {
-	astDot  bool          // display AST graph (debug)
-	cfgDot  bool          // display CFG graph (debug)
-	noRun   bool          // compile, but do not run
-	context build.Context // build context: GOPATH, build constraints
+	astDot   bool          // display AST graph (debug)
+	cfgDot   bool          // display CFG graph (debug)
+	noRun    bool          // compile, but do not run
+	fastChan bool          // disable cancellable chan operations
+	context  build.Context // build context: GOPATH, build constraints
 }
 
 // Interpreter contains global resources and state
 type Interpreter struct {
+	// id is an atomic counter counter used for run cancellation,
+	// only accessed via runid/stop
+	// Located at start of struct to ensure proper alignment on 32 bit
+	// architectures.
+	id uint64
+
 	Name string // program name
-	opt
+
+	opt                        // user settable options
+	cancelChan bool            // enables cancellable chan operations
+	nindex     int64           // next node index
+	fset       *token.FileSet  // fileset to locate node in source code
+	binPkg     Exports         // binary packages used in interpreter, indexed by path
+	rdir       map[string]bool // for src import cycle detection
+
+	mutex    sync.RWMutex
 	frame    *frame            // program data storage during execution
-	nindex   int               // next node index
-	fset     *token.FileSet    // fileset to locate node in source code
 	universe *scope            // interpreter global level scope
 	scopes   map[string]*scope // package level scopes, indexed by package name
-	binPkg   Exports           // binary packages used in interpreter, indexed by path
 	srcPkg   imports           // source packages used in interpreter, indexed by path
-	rdir     map[string]bool   // for src import cycle detection
+	done     chan struct{}     // for cancellation of channel operations
 }
 
 const (
@@ -146,15 +198,17 @@ func New(options Options) *Interpreter {
 		i.opt.context.BuildTags = options.BuildTags
 	}
 
-	// AstDot activates AST graph display for the interpreter
+	// astDot activates AST graph display for the interpreter
 	i.opt.astDot, _ = strconv.ParseBool(os.Getenv("YAEGI_AST_DOT"))
 
-	// CfgDot activates AST graph display for the interpreter
+	// cfgDot activates AST graph display for the interpreter
 	i.opt.cfgDot, _ = strconv.ParseBool(os.Getenv("YAEGI_CFG_DOT"))
 
-	// NoRun disable the execution (but not the compilation) in the interpreter
+	// noRun disables the execution (but not the compilation) in the interpreter
 	i.opt.noRun, _ = strconv.ParseBool(os.Getenv("YAEGI_NO_RUN"))
 
+	// fastChan disables the cancellable version of channel operations in evalWithContext
+	i.opt.fastChan, _ = strconv.ParseBool(os.Getenv("YAEGI_FAST_CHAN"))
 	return &i
 }
 
@@ -227,7 +281,9 @@ func (interp *Interpreter) resizeFrame() {
 }
 
 func (interp *Interpreter) main() *node {
-	if m, ok := interp.scopes[mainID]; ok && m.sym[mainID] != nil {
+	interp.mutex.RLock()
+	defer interp.mutex.RUnlock()
+	if m, ok := interp.scopes[interp.Name]; ok && m.sym[mainID] != nil {
 		return m.sym[mainID].node
 	}
 	return nil
@@ -252,18 +308,18 @@ func (interp *Interpreter) Eval(src string) (reflect.Value, error) {
 	}
 
 	// Global type analysis
-	revisit, err := interp.gta(root, pkgName)
+	revisit, err := interp.gta(root, pkgName, interp.Name)
 	if err != nil {
 		return res, err
 	}
 	for _, n := range revisit {
-		if _, err = interp.gta(n, pkgName); err != nil {
+		if _, err = interp.gta(n, pkgName, interp.Name); err != nil {
 			return res, err
 		}
 	}
 
 	// Annotate AST with CFG infos
-	initNodes, err := interp.cfg(root)
+	initNodes, err := interp.cfg(root, interp.Name)
 	if err != nil {
 		return res, err
 	}
@@ -277,11 +333,13 @@ func (interp *Interpreter) Eval(src string) (reflect.Value, error) {
 		// REPL may skip package statement
 		setExec(root.start)
 	}
+	interp.mutex.Lock()
 	if interp.universe.sym[pkgName] == nil {
 		// Make the package visible under a path identical to its name
-		interp.srcPkg[pkgName] = interp.scopes[pkgName].sym
+		interp.srcPkg[pkgName] = interp.scopes[interp.Name].sym
 		interp.universe.sym[pkgName] = &symbol{kind: pkgSym, typ: &itype{cat: srcPkgT, path: pkgName}}
 	}
+	interp.mutex.Unlock()
 
 	if interp.cfgDot {
 		root.cfgDot(dotX())
@@ -291,11 +349,18 @@ func (interp *Interpreter) Eval(src string) (reflect.Value, error) {
 		return res, err
 	}
 
-	// Execute CFG
+	// Generate node exec closures
 	if err = genRun(root); err != nil {
 		return res, err
 	}
+
+	// Init interpreter execution memory frame
+	interp.frame.setrunid(interp.runid())
+	interp.frame.mutex.Lock()
 	interp.resizeFrame()
+	interp.frame.mutex.Unlock()
+
+	// Execute node closures
 	interp.run(root, nil)
 
 	for _, n := range initNodes {
@@ -314,6 +379,42 @@ func (interp *Interpreter) Eval(src string) (reflect.Value, error) {
 	return res, err
 }
 
+// EvalWithContext evaluates Go code represented as a string. It returns
+// a map on current interpreted package exported symbols.
+func (interp *Interpreter) EvalWithContext(ctx context.Context, src string) (reflect.Value, error) {
+	var v reflect.Value
+	var err error
+
+	interp.mutex.Lock()
+	interp.done = make(chan struct{})
+	interp.cancelChan = !interp.opt.fastChan
+	interp.mutex.Unlock()
+
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		v, err = interp.Eval(src)
+	}()
+
+	select {
+	case <-ctx.Done():
+		interp.stop()
+		return reflect.Value{}, ctx.Err()
+	case <-done:
+		return v, err
+	}
+}
+
+// stop sends a semaphore to all running frames and closes the chan
+// operation short circuit channel. stop may only be called once per
+// invocation of EvalWithContext.
+func (interp *Interpreter) stop() {
+	atomic.AddUint64(&interp.id, 1)
+	close(interp.done)
+}
+
+func (interp *Interpreter) runid() uint64 { return atomic.LoadUint64(&interp.id) }
+
 // getWrapper returns the wrapper type of the corresponding interface, or nil if not found
 func (interp *Interpreter) getWrapper(t reflect.Type) reflect.Type {
 	if p, ok := interp.binPkg[t.PkgPath()]; ok {
@@ -330,16 +431,21 @@ func (interp *Interpreter) Use(values Exports) {
 	}
 }
 
-// Repl performs a Read-Eval-Print-Loop on input file descriptor.
-// Results are printed on output.
-func (interp *Interpreter) Repl(in, out *os.File) {
+// REPL performs a Read-Eval-Print-Loop on input reader.
+// Results are printed on output writer.
+func (interp *Interpreter) REPL(in io.Reader, out io.Writer) {
 	s := bufio.NewScanner(in)
 	prompt := getPrompt(in, out)
 	prompt()
 	src := ""
 	for s.Scan() {
 		src += s.Text() + "\n"
-		if v, err := interp.Eval(src); err != nil {
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		handleSignal(ctx, cancel)
+		v, err := interp.EvalWithContext(ctx, src)
+		signal.Reset()
+		if err != nil {
 			switch err.(type) {
 			case scanner.ErrorList:
 				// Early failure in the scanner: the source is incomplete
@@ -357,10 +463,35 @@ func (interp *Interpreter) Repl(in, out *os.File) {
 	}
 }
 
-// getPrompt returns a function which prints a prompt only if input is a terminal
-func getPrompt(in, out *os.File) func() {
-	if stat, err := in.Stat(); err == nil && stat.Mode()&os.ModeCharDevice != 0 {
+// Repl performs a Read-Eval-Print-Loop on input file descriptor.
+// Results are printed on output.
+// Deprecated: use REPL instead
+func (interp *Interpreter) Repl(in, out *os.File) {
+	interp.REPL(in, out)
+}
+
+// getPrompt returns a function which prints a prompt only if input is a terminal.
+func getPrompt(in io.Reader, out io.Writer) func() {
+	s, ok := in.(interface{ Stat() (os.FileInfo, error) })
+	if !ok {
+		return func() {}
+	}
+	stat, err := s.Stat()
+	if err == nil && stat.Mode()&os.ModeCharDevice != 0 {
 		return func() { fmt.Fprint(out, "> ") }
 	}
 	return func() {}
 }
+
+// handleSignal wraps signal handling for eval cancellation.
+func handleSignal(ctx context.Context, cancel context.CancelFunc) {
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+	go func() {
+		select {
+		case <-c:
+			cancel()
+		case <-ctx.Done():
+		}
+	}()
+}

interp/interp_consistent_test.go

@@ -35,6 +35,8 @@ func TestInterpConsistencyBuild(t *testing.T) {
 			file.Name() == "bad0.go" || // expect error
 			file.Name() == "export1.go" || // non-main package
 			file.Name() == "export0.go" || // non-main package
+			file.Name() == "for7.go" || // expect error
+			file.Name() == "if2.go" || // expect error
 			file.Name() == "import6.go" || // expect error
 			file.Name() == "io0.go" || // use random number
 			file.Name() == "op1.go" || // expect error
@@ -104,7 +106,7 @@ func TestInterpConsistencyBuild(t *testing.T) {
 
 			bin := filepath.Join(dir, strings.TrimSuffix(file.Name(), ".go"))
 
-			cmdBuild := exec.Command("go", "build", "-o", bin, filePath)
+			cmdBuild := exec.Command("go", "build", "-tags=dummy", "-o", bin, filePath)
 			outBuild, err := cmdBuild.CombinedOutput()
 			if err != nil {
 				t.Log(string(outBuild))
@@ -136,6 +138,16 @@ func TestInterpErrorConsistency(t *testing.T) {
 			expectedInterp: "1:1: expected 'package', found println",
 			expectedExec:   "1:1: expected 'package', found println",
 		},
+		{
+			fileName:       "if2.go",
+			expectedInterp: "7:5: non-bool used as if condition",
+			expectedExec:   "7:2: non-bool i % 1000000 (type int) used as if condition",
+		},
+		{
+			fileName:       "for7.go",
+			expectedInterp: "4:14: non-bool used as for condition",
+			expectedExec:   "4:2: non-bool i (type int) used as for condition",
+		},
 		{
 			fileName:       "op1.go",
 			expectedInterp: "5:2: illegal operand types for '+=' operator",

interp/interp_eval_test.go

@@ -1,6 +1,7 @@
 package interp_test
 
 import (
+	"context"
 	"fmt"
 	"log"
 	"net/http"
@@ -41,16 +42,22 @@ func TestEvalArithmetic(t *testing.T) {
 		{desc: "mul_II", src: "2 * 3", res: "6"},
 		{desc: "mul_FI", src: "2.2 * 3", res: "6.6000000000000005"},
 		{desc: "mul_IF", src: "3 * 2.2", res: "6.6000000000000005"},
-		{desc: "rem_FI", src: "8.0 % 4", err: "1:28: illegal operand types for '%' operator"},
+		{desc: "rem_FI", src: "8.2 % 4", err: "1:28: illegal operand types for '%' operator"},
 		{desc: "shl_II", src: "1 << 8", res: "256"},
 		{desc: "shl_IN", src: "1 << -1", err: "1:28: illegal operand types for '<<' operator"},
 		{desc: "shl_IF", src: "1 << 1.0", res: "2"},
 		{desc: "shl_IF1", src: "1 << 1.1", err: "1:28: illegal operand types for '<<' operator"},
-		{desc: "shl_IF", src: "1.0 << 1", res: "2"},
+		{desc: "shl_IF2", src: "1.0 << 1", res: "2"},
 		{desc: "shr_II", src: "1 >> 8", res: "0"},
 		{desc: "shr_IN", src: "1 >> -1", err: "1:28: illegal operand types for '>>' operator"},
 		{desc: "shr_IF", src: "1 >> 1.0", res: "0"},
 		{desc: "shr_IF1", src: "1 >> 1.1", err: "1:28: illegal operand types for '>>' operator"},
+		{desc: "neg_I", src: "-2", res: "-2"},
+		{desc: "pos_I", src: "+2", res: "2"},
+		{desc: "bitnot_I", src: "^2", res: "-3"},
+		{desc: "bitnot_F", src: "^0.2", err: "1:28: illegal operand type for '^' operator"},
+		{desc: "not_B", src: "!false", res: "true"},
+		{desc: "not_I", src: "!0", err: "1:28: illegal operand type for '!' operator"},
 	})
 }
 
@@ -60,7 +67,7 @@ func TestEvalAssign(t *testing.T) {
 		{src: `a := "Hello"; a += " world"`, res: "Hello world"},
 		{src: `b := "Hello"; b += 1`, err: "1:42: illegal operand types for '+=' operator"},
 		{src: `c := "Hello"; c -= " world"`, err: "1:42: illegal operand types for '-=' operator"},
-		{src: "e := 64.0; e %= 64", err: "1:39: illegal operand types for '%=' operator"},
+		{src: "e := 64.4; e %= 64", err: "1:39: illegal operand types for '%=' operator"},
 		{src: "f := int64(3.2)", err: "1:33: truncated to integer"},
 		{src: "g := 1; g <<= 8", res: "256"},
 		{src: "h := 1; h >>= 8", res: "0"},
@@ -155,6 +162,14 @@ func TestEvalNil(t *testing.T) {
 			src: "Hello()",
 			res: "<nil>",
 		},
+		{
+			desc: "return nil func",
+			pre: func() {
+				eval(t, i, `func Bar() func() { return nil }`)
+			},
+			src: "Bar()",
+			res: "<nil>",
+		},
 	})
 }
 
@@ -396,6 +411,100 @@ func TestEvalMissingSymbol(t *testing.T) {
 	}
 }
 
+func TestEvalWithContext(t *testing.T) {
+	tests := []testCase{
+		{
+			desc: "for {}",
+			src: `(func() {
+				      for {}
+			      })()`,
+		},
+		{
+			desc: "select {}",
+			src: `(func() {
+				     select {}
+			     })()`,
+		},
+		{
+			desc: "blocked chan send",
+			src: `(func() {
+			         c := make(chan int)
+				     c <- 1
+				 })()`,
+		},
+		{
+			desc: "blocked chan recv",
+			src: `(func() {
+			         c := make(chan int)
+				     <-c
+			     })()`,
+		},
+		{
+			desc: "blocked chan recv2",
+			src: `(func() {
+			         c := make(chan int)
+				     _, _ = <-c
+			     })()`,
+		},
+		{
+			desc: "blocked range chan",
+			src: `(func() {
+			         c := make(chan int)
+				     for range c {}
+			     })()`,
+		},
+		{
+			desc: "double lock",
+			src: `(func() {
+			         var mu sync.Mutex
+				     mu.Lock()
+				     mu.Lock()
+			      })()`,
+		},
+	}
+
+	for _, test := range tests {
+		done := make(chan struct{})
+		src := test.src
+		go func() {
+			defer close(done)
+			i := interp.New(interp.Options{})
+			i.Use(stdlib.Symbols)
+			_, err := i.Eval(`import "sync"`)
+			if err != nil {
+				t.Errorf(`failed to import "sync": %v`, err)
+				return
+			}
+			ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+			defer cancel()
+			_, err = i.EvalWithContext(ctx, src)
+			switch err {
+			case context.DeadlineExceeded:
+				// Successful cancellation.
+
+				// Check we can still execute an expression.
+				v, err := i.EvalWithContext(context.Background(), "1+1\n") //nolint:govet
+				if err != nil {
+					t.Errorf("failed to evaluate expression after cancellation: %v", err)
+				}
+				got := v.Interface()
+				if got != 2 {
+					t.Errorf("unexpected result of eval(1+1): got %v, want 2", got)
+				}
+			case nil:
+				t.Errorf("unexpected success evaluating expression %q", test.desc)
+			default:
+				t.Errorf("failed to evaluate expression %q: %v", test.desc, err)
+			}
+		}()
+		select {
+		case <-time.After(time.Second):
+			t.Errorf("timeout failed to terminate execution of %q", test.desc)
+		case <-done:
+		}
+	}
+}
+
 func runTests(t *testing.T, i *interp.Interpreter, tests []testCase) {
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {

interp/op.go

@@ -1,6 +1,6 @@
 package interp
 
-// Code generated by 'go run ../cmd/genop/genop.go'. DO NOT EDIT.
+// Code generated by 'go run ../internal/genop/genop.go'. DO NOT EDIT.
 
 import "reflect"
 
@@ -1864,6 +1864,57 @@ func inc(n *node) {
 	}
 }
 
+func bitNotConst(n *node) {
+	t := n.typ.rtype
+	v := n.child[0].rval
+	n.rval = reflect.New(t).Elem()
+	switch t.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		n.rval.SetInt(^v.Int())
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		n.rval.SetUint(^v.Uint())
+	}
+}
+
+func negConst(n *node) {
+	t := n.typ.rtype
+	v := n.child[0].rval
+	n.rval = reflect.New(t).Elem()
+	switch t.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		n.rval.SetInt(-v.Int())
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		n.rval.SetUint(-v.Uint())
+	case reflect.Float32, reflect.Float64:
+		n.rval.SetFloat(-v.Float())
+	case reflect.Complex64, reflect.Complex128:
+		n.rval.SetComplex(-v.Complex())
+	}
+}
+
+func notConst(n *node) {
+	t := n.typ.rtype
+	v := n.child[0].rval
+	n.rval = reflect.New(t).Elem()
+	n.rval.SetBool(!v.Bool())
+}
+
+func posConst(n *node) {
+	t := n.typ.rtype
+	v := n.child[0].rval
+	n.rval = reflect.New(t).Elem()
+	switch t.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		n.rval.SetInt(+v.Int())
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		n.rval.SetUint(+v.Uint())
+	case reflect.Float32, reflect.Float64:
+		n.rval.SetFloat(+v.Float())
+	case reflect.Complex64, reflect.Complex128:
+		n.rval.SetComplex(+v.Complex())
+	}
+}
+
 func equal(n *node) {
 	tnext := getExec(n.tnext)
 	dest := genValue(n)
@@ -1938,146 +1989,6 @@ func equal(n *node) {
 				}
 			}
 		}
-	case isComplex(t0) || isComplex(t1):
-		switch {
-		case c0.rval.IsValid():
-			s0 := vComplex(c0.rval)
-			v1 := genValueComplex(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s1 := v1(f)
-					if s0 == s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				n.exec = func(f *frame) bltn {
-					_, s1 := v1(f)
-					dest(f).SetBool(s0 == s1)
-					return tnext
-				}
-			}
-		case c1.rval.IsValid():
-			s1 := vComplex(c1.rval)
-			v0 := genValueComplex(c0)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					if s0 == s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					dest(f).SetBool(s0 == s1)
-					return tnext
-				}
-			}
-		default:
-			v0 := genValueComplex(n.child[0])
-			v1 := genValueComplex(n.child[1])
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					_, s1 := v1(f)
-					if s0 == s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					_, s1 := v1(f)
-					dest(f).SetBool(s0 == s1)
-					return tnext
-				}
-			}
-		}
-	default:
-		switch {
-		case c0.rval.IsValid():
-			i0 := c0.rval.Interface()
-			v1 := genValue(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i1 := v1(f).Interface()
-					if i0 == i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i1 := v1(f).Interface()
-					dest(f).SetBool(i0 == i1)
-					return tnext
-				}
-			}
-		case c1.rval.IsValid():
-			i1 := c1.rval.Interface()
-			v0 := genValue(c0)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					if i0 == i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					dest(f).SetBool(i0 == i1)
-					return tnext
-				}
-			}
-		default:
-			v0 := genValue(c0)
-			v1 := genValue(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					i1 := v1(f).Interface()
-					if i0 == i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					i1 := v1(f).Interface()
-					dest(f).SetBool(i0 == i1)
-					return tnext
-				}
-			}
-		}
 	case isFloat(t0) || isFloat(t1):
 		switch {
 		case c0.rval.IsValid():
@@ -2290,6 +2201,146 @@ func equal(n *node) {
 				}
 			}
 		}
+	case isComplex(t0) || isComplex(t1):
+		switch {
+		case c0.rval.IsValid():
+			s0 := vComplex(c0.rval)
+			v1 := genComplex(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s1 := v1(f)
+					if s0 == s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				n.exec = func(f *frame) bltn {
+					s1 := v1(f)
+					dest(f).SetBool(s0 == s1)
+					return tnext
+				}
+			}
+		case c1.rval.IsValid():
+			s1 := vComplex(c1.rval)
+			v0 := genComplex(c0)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					if s0 == s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					dest(f).SetBool(s0 == s1)
+					return tnext
+				}
+			}
+		default:
+			v0 := genComplex(n.child[0])
+			v1 := genComplex(n.child[1])
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					s1 := v1(f)
+					if s0 == s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					s1 := v1(f)
+					dest(f).SetBool(s0 == s1)
+					return tnext
+				}
+			}
+		}
+	default:
+		switch {
+		case c0.rval.IsValid():
+			i0 := c0.rval.Interface()
+			v1 := genValue(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i1 := v1(f).Interface()
+					if i0 == i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i1 := v1(f).Interface()
+					dest(f).SetBool(i0 == i1)
+					return tnext
+				}
+			}
+		case c1.rval.IsValid():
+			i1 := c1.rval.Interface()
+			v0 := genValue(c0)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					if i0 == i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					dest(f).SetBool(i0 == i1)
+					return tnext
+				}
+			}
+		default:
+			v0 := genValue(c0)
+			v1 := genValue(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					i1 := v1(f).Interface()
+					if i0 == i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					i1 := v1(f).Interface()
+					dest(f).SetBool(i0 == i1)
+					return tnext
+				}
+			}
+		}
 	}
 }
 
@@ -3523,146 +3574,6 @@ func notEqual(n *node) {
 				}
 			}
 		}
-	case isComplex(t0) || isComplex(t1):
-		switch {
-		case c0.rval.IsValid():
-			s0 := vComplex(c0.rval)
-			v1 := genValueComplex(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s1 := v1(f)
-					if s0 != s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				n.exec = func(f *frame) bltn {
-					_, s1 := v1(f)
-					dest(f).SetBool(s0 != s1)
-					return tnext
-				}
-			}
-		case c1.rval.IsValid():
-			s1 := vComplex(c1.rval)
-			v0 := genValueComplex(c0)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					if s0 != s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					dest(f).SetBool(s0 != s1)
-					return tnext
-				}
-			}
-		default:
-			v0 := genValueComplex(n.child[0])
-			v1 := genValueComplex(n.child[1])
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					_, s1 := v1(f)
-					if s0 != s1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				n.exec = func(f *frame) bltn {
-					_, s0 := v0(f)
-					_, s1 := v1(f)
-					dest(f).SetBool(s0 != s1)
-					return tnext
-				}
-			}
-		}
-	default:
-		switch {
-		case c0.rval.IsValid():
-			i0 := c0.rval.Interface()
-			v1 := genValue(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i1 := v1(f).Interface()
-					if i0 != i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i1 := v1(f).Interface()
-					dest(f).SetBool(i0 != i1)
-					return tnext
-				}
-			}
-		case c1.rval.IsValid():
-			i1 := c1.rval.Interface()
-			v0 := genValue(c0)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					if i0 != i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					dest(f).SetBool(i0 != i1)
-					return tnext
-				}
-			}
-		default:
-			v0 := genValue(c0)
-			v1 := genValue(c1)
-			if n.fnext != nil {
-				fnext := getExec(n.fnext)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					i1 := v1(f).Interface()
-					if i0 != i1 {
-						dest(f).SetBool(true)
-						return tnext
-					}
-					dest(f).SetBool(false)
-					return fnext
-				}
-			} else {
-				dest := genValue(n)
-				n.exec = func(f *frame) bltn {
-					i0 := v0(f).Interface()
-					i1 := v1(f).Interface()
-					dest(f).SetBool(i0 != i1)
-					return tnext
-				}
-			}
-		}
 	case isFloat(t0) || isFloat(t1):
 		switch {
 		case c0.rval.IsValid():
@@ -3875,5 +3786,145 @@ func notEqual(n *node) {
 				}
 			}
 		}
+	case isComplex(t0) || isComplex(t1):
+		switch {
+		case c0.rval.IsValid():
+			s0 := vComplex(c0.rval)
+			v1 := genComplex(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s1 := v1(f)
+					if s0 != s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				n.exec = func(f *frame) bltn {
+					s1 := v1(f)
+					dest(f).SetBool(s0 != s1)
+					return tnext
+				}
+			}
+		case c1.rval.IsValid():
+			s1 := vComplex(c1.rval)
+			v0 := genComplex(c0)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					if s0 != s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					dest(f).SetBool(s0 != s1)
+					return tnext
+				}
+			}
+		default:
+			v0 := genComplex(n.child[0])
+			v1 := genComplex(n.child[1])
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					s1 := v1(f)
+					if s0 != s1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				n.exec = func(f *frame) bltn {
+					s0 := v0(f)
+					s1 := v1(f)
+					dest(f).SetBool(s0 != s1)
+					return tnext
+				}
+			}
+		}
+	default:
+		switch {
+		case c0.rval.IsValid():
+			i0 := c0.rval.Interface()
+			v1 := genValue(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i1 := v1(f).Interface()
+					if i0 != i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i1 := v1(f).Interface()
+					dest(f).SetBool(i0 != i1)
+					return tnext
+				}
+			}
+		case c1.rval.IsValid():
+			i1 := c1.rval.Interface()
+			v0 := genValue(c0)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					if i0 != i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					dest(f).SetBool(i0 != i1)
+					return tnext
+				}
+			}
+		default:
+			v0 := genValue(c0)
+			v1 := genValue(c1)
+			if n.fnext != nil {
+				fnext := getExec(n.fnext)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					i1 := v1(f).Interface()
+					if i0 != i1 {
+						dest(f).SetBool(true)
+						return tnext
+					}
+					dest(f).SetBool(false)
+					return fnext
+				}
+			} else {
+				dest := genValue(n)
+				n.exec = func(f *frame) bltn {
+					i0 := v0(f).Interface()
+					i1 := v1(f).Interface()
+					dest(f).SetBool(i0 != i1)
+					return tnext
+				}
+			}
+		}
 	}
 }

interp/run.go

@@ -24,6 +24,7 @@ var builtin = [...]bltnGenerator{
 	aAndAssign:    andAssign,
 	aAndNot:       andNot,
 	aAndNotAssign: andNotAssign,
+	aBitNot:       bitNot,
 	aCall:         call,
 	aCase:         _case,
 	aCompositeLit: arrayLit,
@@ -40,11 +41,12 @@ var builtin = [...]bltnGenerator{
 	aLowerEqual:   lowerEqual,
 	aMul:          mul,
 	aMulAssign:    mulAssign,
-	aNegate:       negate,
+	aNeg:          neg,
 	aNot:          not,
 	aNotEqual:     notEqual,
 	aOr:           or,
 	aOrAssign:     orAssign,
+	aPos:          pos,
 	aQuo:          quo,
 	aQuoAssign:    quoAssign,
 	aRange:        _range,
@@ -84,8 +86,11 @@ func (interp *Interpreter) run(n *node, cf *frame) {
 	if cf == nil {
 		f = interp.frame
 	} else {
-		f = &frame{anc: cf, data: make([]reflect.Value, len(n.types))}
+		f = newFrame(cf, len(n.types), interp.runid())
 	}
+	interp.mutex.RLock()
+	f.done = reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(interp.done)}
+	interp.mutex.RUnlock()
 
 	for i, t := range n.types {
 		f.data[i] = reflect.New(t).Elem()
@@ -98,42 +103,76 @@ func (interp *Interpreter) run(n *node, cf *frame) {
 // runCfg executes a node AST by walking its CFG and running node builtin at each step
 func runCfg(n *node, f *frame) {
 	defer func() {
+		f.mutex.Lock()
 		f.recovered = recover()
 		for _, val := range f.deferred {
 			val[0].Call(val[1:])
 		}
 		if f.recovered != nil {
 			fmt.Println(n.cfgErrorf("panic"))
+			f.mutex.Unlock()
 			panic(f.recovered)
 		}
+		f.mutex.Unlock()
 	}()
 
-	for exec := n.exec; exec != nil; {
+	for exec := n.exec; exec != nil && f.runid() == n.interp.runid(); {
 		exec = exec(f)
 	}
 }
 
-func typeAssert(n *node) {
-	value := genValue(n.child[0])
-	i := n.findex
+func typeAssertStatus(n *node) {
+	value := genValue(n.child[0])      // input value
+	value1 := genValue(n.anc.child[1]) // returned status
 	next := getExec(n.tnext)
 
 	switch {
 	case n.child[0].typ.cat == valueT:
 		n.exec = func(f *frame) bltn {
-			f.data[i].Set(value(f).Elem())
+			if !value(f).IsValid() || value(f).IsNil() {
+				value1(f).SetBool(false)
+			}
+			value1(f).SetBool(true)
+			return next
+		}
+	case n.child[1].typ.cat == interfaceT:
+		n.exec = func(f *frame) bltn {
+			_, ok := value(f).Interface().(valueInterface)
+			//value0(f).Set(reflect.ValueOf(valueInterface{v.node, v.value}))
+			value1(f).SetBool(ok)
+			return next
+		}
+	default:
+		n.exec = func(f *frame) bltn {
+			_, ok := value(f).Interface().(valueInterface)
+			//value0(f).Set(v.value)
+			value1(f).SetBool(ok)
+			return next
+		}
+	}
+}
+
+func typeAssert(n *node) {
+	value := genValue(n.child[0]) // input value
+	dest := genValue(n)           // returned result
+	next := getExec(n.tnext)
+
+	switch {
+	case n.child[0].typ.cat == valueT:
+		n.exec = func(f *frame) bltn {
+			dest(f).Set(value(f).Elem())
 			return next
 		}
 	case n.child[1].typ.cat == interfaceT:
 		n.exec = func(f *frame) bltn {
 			v := value(f).Interface().(valueInterface)
-			f.data[i] = reflect.ValueOf(valueInterface{v.node, v.value})
+			dest(f).Set(reflect.ValueOf(valueInterface{v.node, v.value}))
 			return next
 		}
 	default:
 		n.exec = func(f *frame) bltn {
 			v := value(f).Interface().(valueInterface)
-			f.data[i].Set(v.value)
+			dest(f).Set(v.value)
 			return next
 		}
 	}
@@ -202,7 +241,7 @@ func isRecursiveStruct(t *itype, rtype reflect.Type) bool {
 	if t.cat == structT && rtype.Kind() == reflect.Interface {
 		return true
 	}
-	if t.cat == ptrT {
+	if t.cat == ptrT && t.rtype != nil {
 		return isRecursiveStruct(t.val, t.rtype.Elem())
 	}
 	return false
@@ -223,15 +262,21 @@ func assign(n *node) {
 		switch {
 		case dest.typ.cat == interfaceT:
 			svalue[i] = genValueInterface(src)
-		case dest.typ.cat == valueT && dest.typ.rtype.Kind() == reflect.Interface:
+		case (dest.typ.cat == valueT || dest.typ.cat == errorT) && dest.typ.rtype.Kind() == reflect.Interface:
 			svalue[i] = genInterfaceWrapper(src, dest.typ.rtype)
 		case dest.typ.cat == valueT && src.typ.cat == funcT:
 			svalue[i] = genFunctionWrapper(src)
+		case dest.typ.cat == funcT && src.typ.cat == valueT:
+			svalue[i] = genValueNode(src)
 		case src.kind == basicLit && src.val == nil:
 			t := dest.typ.TypeOf()
 			svalue[i] = func(*frame) reflect.Value { return reflect.New(t).Elem() }
 		case isRecursiveStruct(dest.typ, dest.typ.rtype):
 			svalue[i] = genValueInterfacePtr(src)
+		case src.typ.untyped && isComplex(dest.typ.TypeOf()):
+			svalue[i] = genValueComplex(src)
+		case src.typ.untyped && !dest.typ.untyped:
+			svalue[i] = genValueAs(src, dest.typ.TypeOf())
 		default:
 			svalue[i] = genValue(src)
 		}
@@ -248,12 +293,17 @@ func assign(n *node) {
 	}
 
 	if n.nleft == 1 {
-		if s, d, i := svalue[0], dvalue[0], ivalue[0]; i != nil {
+		switch s, d, i := svalue[0], dvalue[0], ivalue[0]; {
+		case n.child[0].ident == "_":
+			n.exec = func(f *frame) bltn {
+				return next
+			}
+		case i != nil:
 			n.exec = func(f *frame) bltn {
 				d(f).SetMapIndex(i(f), s(f))
 				return next
 			}
-		} else {
+		default:
 			n.exec = func(f *frame) bltn {
 				d(f).Set(s(f))
 				return next
@@ -271,7 +321,6 @@ func assign(n *node) {
 			default:
 				t = typ.TypeOf()
 			}
-			//types[i] = n.child[sbase+i].typ.TypeOf()
 			types[i] = t
 		}
 
@@ -281,10 +330,16 @@ func assign(n *node) {
 		n.exec = func(f *frame) bltn {
 			t := make([]reflect.Value, len(svalue))
 			for i, s := range svalue {
+				if n.child[i].ident == "_" {
+					continue
+				}
 				t[i] = reflect.New(types[i]).Elem()
 				t[i].Set(s(f))
 			}
 			for i, d := range dvalue {
+				if n.child[i].ident == "_" {
+					continue
+				}
 				if j := ivalue[i]; j != nil {
 					d(f).SetMapIndex(j(f), t[i]) // Assign a map entry
 				} else {
@@ -297,21 +352,24 @@ func assign(n *node) {
 }
 
 func not(n *node) {
+	dest := genValue(n)
 	value := genValue(n.child[0])
 	tnext := getExec(n.tnext)
+	i := n.findex
 
 	if n.fnext != nil {
 		fnext := getExec(n.fnext)
 		n.exec = func(f *frame) bltn {
 			if !value(f).Bool() {
+				f.data[i].SetBool(true)
 				return tnext
 			}
+			f.data[i].SetBool(false)
 			return fnext
 		}
 	} else {
-		i := n.findex
 		n.exec = func(f *frame) bltn {
-			f.data[i].SetBool(!value(f).Bool())
+			dest(f).SetBool(!value(f).Bool())
 			return tnext
 		}
 	}
@@ -416,6 +474,10 @@ func _panic(n *node) {
 func genFunctionWrapper(n *node) func(*frame) reflect.Value {
 	var def *node
 	var ok bool
+
+	if n.kind == basicLit {
+		return func(f *frame) reflect.Value { return n.rval }
+	}
 	if def, ok = n.val.(*node); !ok {
 		return genValueAsFunctionWrapper(n)
 	}
@@ -438,7 +500,7 @@ func genFunctionWrapper(n *node) func(*frame) reflect.Value {
 		}
 		return reflect.MakeFunc(n.typ.TypeOf(), func(in []reflect.Value) []reflect.Value {
 			// Allocate and init local frame. All values to be settable and addressable.
-			fr := frame{anc: f, data: make([]reflect.Value, len(def.types))}
+			fr := newFrame(f, len(def.types), f.runid())
 			d := fr.data
 			for i, t := range def.types {
 				d[i] = reflect.New(t).Elem()
@@ -467,7 +529,7 @@ func genFunctionWrapper(n *node) func(*frame) reflect.Value {
 			}
 
 			// Interpreter code execution
-			runCfg(start, &fr)
+			runCfg(start, fr)
 
 			result := fr.data[:numRet]
 			for i, r := range result {
@@ -611,7 +673,7 @@ func call(n *node) {
 				values = append(values, func(f *frame) reflect.Value { return f.data[ind] })
 			}
 		default:
-			if c.kind == basicLit {
+			if c.kind == basicLit || c.rval.IsValid() {
 				var argType reflect.Type
 				if variadic >= 0 && i >= variadic {
 					argType = n.child[0].typ.arg[variadic].val.TypeOf()
@@ -647,12 +709,35 @@ func call(n *node) {
 
 	n.exec = func(f *frame) bltn {
 		def := value(f).Interface().(*node)
+
+		// Call bin func if defined
+		if def.rval.IsValid() {
+			in := make([]reflect.Value, len(values))
+			for i, v := range values {
+				in[i] = v(f)
+			}
+			if goroutine {
+				go def.rval.Call(in)
+				return tnext
+			}
+			out := def.rval.Call(in)
+			for i, v := range rvalues {
+				if v != nil {
+					v(f).Set(out[i])
+				}
+			}
+			if fnext != nil && !out[0].Bool() {
+				return fnext
+			}
+			return tnext
+		}
+
 		anc := f
 		// Get closure frame context (if any)
 		if def.frame != nil {
 			anc = def.frame
 		}
-		nf := frame{anc: anc, data: make([]reflect.Value, len(def.types))}
+		nf := newFrame(anc, len(def.types), anc.runid())
 		var vararg reflect.Value
 
 		// Init return values
@@ -717,10 +802,10 @@ func call(n *node) {
 
 		// Execute function body
 		if goroutine {
-			go runCfg(def.child[3].start, &nf)
+			go runCfg(def.child[3].start, nf)
 			return tnext
 		}
-		runCfg(def.child[3].start, &nf)
+		runCfg(def.child[3].start, nf)
 
 		// Handle branching according to boolean result
 		if fnext != nil && !nf.data[0].Bool() {
@@ -753,7 +838,9 @@ func callBin(n *node) {
 	// method signature obtained from reflect.Type include receiver as 1st arg, except for interface types
 	rcvrOffset := 0
 	if recv := n.child[0].recv; recv != nil && recv.node.typ.TypeOf().Kind() != reflect.Interface {
-		rcvrOffset = 1
+		if funcType.NumIn() > len(child) {
+			rcvrOffset = 1
+		}
 	}
 
 	for i, c := range child {
@@ -773,7 +860,7 @@ func callBin(n *node) {
 				values = append(values, func(f *frame) reflect.Value { return f.data[ind] })
 			}
 		default:
-			if c.kind == basicLit {
+			if c.kind == basicLit || c.rval.IsValid() {
 				// Convert literal value (untyped) to function argument type (if not an interface{})
 				var argType reflect.Type
 				if variadic >= 0 && i >= variadic {
@@ -792,7 +879,6 @@ func callBin(n *node) {
 			case interfaceT:
 				values = append(values, genValueInterfaceValue(c))
 			default:
-				//values = append(values, genValue(c))
 				values = append(values, genInterfaceWrapper(c, defType))
 			}
 		}
@@ -1022,10 +1108,10 @@ func getFunc(n *node) {
 	next := getExec(n.tnext)
 
 	n.exec = func(f *frame) bltn {
-		fr := *f
+		fr := f.clone()
 		nod := *n
 		nod.val = &nod
-		nod.frame = &fr
+		nod.frame = fr
 		dest(f).Set(reflect.ValueOf(&nod))
 		return next
 	}
@@ -1036,11 +1122,11 @@ func getMethod(n *node) {
 	next := getExec(n.tnext)
 
 	n.exec = func(f *frame) bltn {
-		fr := *f
+		fr := f.clone()
 		nod := *(n.val.(*node))
 		nod.val = &nod
 		nod.recv = n.recv
-		nod.frame = &fr
+		nod.frame = fr
 		f.data[i] = reflect.ValueOf(&nod)
 		return next
 	}
@@ -1055,11 +1141,11 @@ func getMethodByName(n *node) {
 	n.exec = func(f *frame) bltn {
 		val := value0(f).Interface().(valueInterface)
 		m, li := val.node.typ.lookupMethod(name)
-		fr := *f
+		fr := f.clone()
 		nod := *m
 		nod.val = &nod
 		nod.recv = &receiver{nil, val.value, li}
-		nod.frame = &fr
+		nod.frame = fr
 		f.data[i] = reflect.ValueOf(&nod)
 		return next
 	}
@@ -1176,7 +1262,7 @@ func getIndexSeqMethod(n *node) {
 	}
 }
 
-func negate(n *node) {
+func neg(n *node) {
 	dest := genValue(n)
 	value := genValue(n.child[0])
 	next := getExec(n.tnext)
@@ -1200,6 +1286,37 @@ func negate(n *node) {
 	}
 }
 
+func pos(n *node) {
+	dest := genValue(n)
+	value := genValue(n.child[0])
+	next := getExec(n.tnext)
+
+	n.exec = func(f *frame) bltn {
+		dest(f).Set(value(f))
+		return next
+	}
+}
+
+func bitNot(n *node) {
+	dest := genValue(n)
+	value := genValue(n.child[0])
+	next := getExec(n.tnext)
+	typ := n.typ.TypeOf()
+
+	switch typ.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		n.exec = func(f *frame) bltn {
+			dest(f).SetInt(^value(f).Int())
+			return next
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		n.exec = func(f *frame) bltn {
+			dest(f).SetUint(^value(f).Uint())
+			return next
+		}
+	}
+}
+
 func land(n *node) {
 	value0 := genValue(n.child[0])
 	value1 := genValue(n.child[1])
@@ -1284,10 +1401,16 @@ func _return(n *node) {
 			} else {
 				values[i] = genValue(c)
 			}
+		case funcT:
+			values[i] = genValue(c)
 		case interfaceT:
 			values[i] = genValueInterface(c)
 		default:
-			values[i] = genValue(c)
+			if c.typ.untyped {
+				values[i] = genValueAs(c, def.typ.ret[i].TypeOf())
+			} else {
+				values[i] = genValue(c)
+			}
 		}
 	}
 
@@ -1351,7 +1474,7 @@ func arrayLit(n *node) {
 	}
 
 	var a reflect.Value
-	if n.typ.size > 0 {
+	if n.typ.sizedef {
 		a, _ = n.typ.zero()
 	} else {
 		a = reflect.MakeSlice(n.typ.TypeOf(), max, max)
@@ -1460,6 +1583,15 @@ func compositeBinStruct(n *node) {
 	}
 }
 
+func destType(n *node) *itype {
+	switch n.anc.kind {
+	case assignStmt, defineStmt:
+		return n.anc.child[0].typ
+	default:
+		return n.typ
+	}
+}
+
 // compositeLit creates and populates a struct object
 func compositeLit(n *node) {
 	value := valueGenerator(n, n.findex)
@@ -1468,6 +1600,7 @@ func compositeLit(n *node) {
 	if !n.typ.untyped {
 		child = n.child[1:]
 	}
+	destInterface := destType(n).cat == interfaceT
 
 	values := make([]func(*frame) reflect.Value, len(child))
 	for i, c := range child {
@@ -1484,9 +1617,12 @@ func compositeLit(n *node) {
 		for i, v := range values {
 			a.Field(i).Set(v(f))
 		}
-		if d := value(f); d.Type().Kind() == reflect.Ptr {
+		switch d := value(f); {
+		case d.Type().Kind() == reflect.Ptr:
 			d.Set(a.Addr())
-		} else {
+		case destInterface:
+			d.Set(reflect.ValueOf(valueInterface{n, a}))
+		default:
 			d.Set(a)
 		}
 		return next
@@ -1534,6 +1670,7 @@ var rat = reflect.ValueOf((*[]rune)(nil)).Type().Elem() // runes array type
 
 func _range(n *node) {
 	index0 := n.child[0].findex // array index location in frame
+	index2 := index0 - 1        // shallow array for range, always just behind index0
 	fnext := getExec(n.fnext)
 	tnext := getExec(n.tnext)
 
@@ -1544,10 +1681,10 @@ func _range(n *node) {
 		if isString(an.typ.TypeOf()) {
 			value = genValueAs(an, rat) // range on string iterates over runes
 		} else {
-			value = genValueArray(an)
+			value = genValueRangeArray(an)
 		}
 		n.exec = func(f *frame) bltn {
-			a := value(f)
+			a := f.data[index2]
 			v0 := f.data[index0]
 			v0.SetInt(v0.Int() + 1)
 			i := int(v0.Int())
@@ -1562,13 +1699,12 @@ func _range(n *node) {
 		if isString(an.typ.TypeOf()) {
 			value = genValueAs(an, rat) // range on string iterates over runes
 		} else {
-			value = genValueArray(an)
+			value = genValueRangeArray(an)
 		}
 		n.exec = func(f *frame) bltn {
-			a := value(f)
 			v0 := f.data[index0]
 			v0.SetInt(v0.Int() + 1)
-			if int(v0.Int()) >= a.Len() {
+			if int(v0.Int()) >= f.data[index2].Len() {
 				return fnext
 			}
 			return tnext
@@ -1578,7 +1714,8 @@ func _range(n *node) {
 	// Init sequence
 	next := n.exec
 	n.child[0].exec = func(f *frame) bltn {
-		f.data[index0].SetInt(-1)
+		f.data[index2] = value(f) // set array shallow copy for range
+		f.data[index0].SetInt(-1) // assing index value
 		return next
 	}
 }
@@ -1590,7 +1727,10 @@ func rangeChan(n *node) {
 	tnext := getExec(n.tnext)
 
 	n.exec = func(f *frame) bltn {
-		v, ok := value(f).Recv()
+		chosen, v, ok := reflect.Select([]reflect.SelectCase{f.done, {Dir: reflect.SelectRecv, Chan: value(f)}})
+		if chosen == 0 {
+			return nil
+		}
 		if !ok {
 			return fnext
 		}
@@ -1600,31 +1740,40 @@ func rangeChan(n *node) {
 }
 
 func rangeMap(n *node) {
-	index0 := n.child[0].findex   // array index location in frame
-	index1 := n.child[1].findex   // array value location in frame
-	value := genValue(n.child[2]) // array
+	index0 := n.child[0].findex // map index location in frame
+	index2 := index0 - 1        // iterator for range, always just behind index0
 	fnext := getExec(n.fnext)
 	tnext := getExec(n.tnext)
-	// TODO: move i and keys to frame
-	var i int
-	var keys []reflect.Value
 
-	n.exec = func(f *frame) bltn {
-		a := value(f)
-		i++
-		if i >= a.Len() {
-			return fnext
+	var value func(*frame) reflect.Value
+	if len(n.child) == 4 {
+		index1 := n.child[1].findex  // map value location in frame
+		value = genValue(n.child[2]) // map
+		n.exec = func(f *frame) bltn {
+			iter := f.data[index2].Interface().(*reflect.MapIter)
+			if !iter.Next() {
+				return fnext
+			}
+			f.data[index0].Set(iter.Key())
+			f.data[index1].Set(iter.Value())
+			return tnext
+		}
+	} else {
+		value = genValue(n.child[1]) // map
+		n.exec = func(f *frame) bltn {
+			iter := f.data[index2].Interface().(*reflect.MapIter)
+			if !iter.Next() {
+				return fnext
+			}
+			f.data[index0].Set(iter.Key())
+			return tnext
 		}
-		f.data[index0].Set(keys[i])
-		f.data[index1].Set(a.MapIndex(keys[i]))
-		return tnext
 	}
 
 	// Init sequence
 	next := n.exec
 	n.child[0].exec = func(f *frame) bltn {
-		keys = value(f).MapKeys()
-		i = -1
+		f.data[index2].Set(reflect.ValueOf(value(f).MapRange()))
 		return next
 	}
 }
@@ -1757,7 +1906,6 @@ func appendSlice(n *node) {
 			return next
 		}
 	}
-
 }
 
 func _append(n *node) {
@@ -1845,39 +1993,48 @@ func _close(n *node) {
 }
 
 func _complex(n *node) {
-	i := n.findex
-	convertLiteralValue(n.child[1], floatType)
-	convertLiteralValue(n.child[2], floatType)
-	value0 := genValue(n.child[1])
-	value1 := genValue(n.child[2])
+	dest := genValue(n)
+	c1, c2 := n.child[1], n.child[2]
+	convertLiteralValue(c1, floatType)
+	convertLiteralValue(c2, floatType)
+	value0 := genValue(c1)
+	value1 := genValue(c2)
 	next := getExec(n.tnext)
 
-	n.exec = func(f *frame) bltn {
-		f.data[i].SetComplex(complex(value0(f).Float(), value1(f).Float()))
-		return next
+	if typ := n.typ.TypeOf(); isComplex(typ) {
+		n.exec = func(f *frame) bltn {
+			dest(f).SetComplex(complex(value0(f).Float(), value1(f).Float()))
+			return next
+		}
+	} else {
+		// Not a complex type: ignore imaginary part
+		n.exec = func(f *frame) bltn {
+			dest(f).Set(value0(f).Convert(typ))
+			return next
+		}
 	}
 }
 
 func _imag(n *node) {
-	i := n.findex
+	dest := genValue(n)
 	convertLiteralValue(n.child[1], complexType)
 	value := genValue(n.child[1])
 	next := getExec(n.tnext)
 
 	n.exec = func(f *frame) bltn {
-		f.data[i].SetFloat(imag(value(f).Complex()))
+		dest(f).SetFloat(imag(value(f).Complex()))
 		return next
 	}
 }
 
 func _real(n *node) {
-	i := n.findex
+	dest := genValue(n)
 	convertLiteralValue(n.child[1], complexType)
 	value := genValue(n.child[1])
 	next := getExec(n.tnext)
 
 	n.exec = func(f *frame) bltn {
-		f.data[i].SetFloat(real(value(f).Complex()))
+		dest(f).SetFloat(real(value(f).Complex()))
 		return next
 	}
 }
@@ -1895,12 +2052,12 @@ func _delete(n *node) {
 }
 
 func _len(n *node) {
-	i := n.findex
+	dest := genValue(n)
 	value := genValue(n.child[1])
 	next := getExec(n.tnext)
 
 	n.exec = func(f *frame) bltn {
-		f.data[i].SetInt(int64(value(f).Len()))
+		dest(f).SetInt(int64(value(f).Len()))
 		return next
 	}
 }
@@ -2014,19 +2171,63 @@ func recv(n *node) {
 	value := genValue(n.child[0])
 	tnext := getExec(n.tnext)
 
-	if n.fnext != nil {
-		fnext := getExec(n.fnext)
-		n.exec = func(f *frame) bltn {
-			if v, _ := value(f).Recv(); v.Bool() {
+	if n.interp.cancelChan {
+		// Cancellable channel read
+		if n.fnext != nil {
+			fnext := getExec(n.fnext)
+			n.exec = func(f *frame) bltn {
+				ch := value(f)
+				// Fast: channel read doesn't block
+				if x, ok := ch.TryRecv(); ok {
+					if x.Bool() {
+						return tnext
+					}
+					return fnext
+				}
+				// Slow: channel read blocks, allow cancel
+				chosen, v, _ := reflect.Select([]reflect.SelectCase{f.done, {Dir: reflect.SelectRecv, Chan: ch}})
+				if chosen == 0 {
+					return nil
+				}
+				if v.Bool() {
+					return tnext
+				}
+				return fnext
+			}
+		} else {
+			i := n.findex
+			n.exec = func(f *frame) bltn {
+				// Fast: channel read doesn't block
+				var ok bool
+				ch := value(f)
+				if f.data[i], ok = ch.TryRecv(); ok {
+					return tnext
+				}
+				// Slow: channel is blocked, allow cancel
+				var chosen int
+				chosen, f.data[i], _ = reflect.Select([]reflect.SelectCase{f.done, {Dir: reflect.SelectRecv, Chan: ch}})
+				if chosen == 0 {
+					return nil
+				}
 				return tnext
 			}
-			return fnext
 		}
 	} else {
-		i := n.findex
-		n.exec = func(f *frame) bltn {
-			f.data[i], _ = value(f).Recv()
-			return tnext
+		// Blocking channel read (less overhead)
+		if n.fnext != nil {
+			fnext := getExec(n.fnext)
+			n.exec = func(f *frame) bltn {
+				if v, _ := value(f).Recv(); v.Bool() {
+					return tnext
+				}
+				return fnext
+			}
+		} else {
+			i := n.findex
+			n.exec = func(f *frame) bltn {
+				f.data[i], _ = value(f).Recv()
+				return tnext
+			}
 		}
 	}
 }
@@ -2037,22 +2238,47 @@ func recv2(n *node) {
 	vok := genValue(n.anc.child[1])  // status
 	tnext := getExec(n.tnext)
 
-	n.exec = func(f *frame) bltn {
-		v, ok := vchan(f).Recv()
-		vres(f).Set(v)
-		vok(f).SetBool(ok)
-		return tnext
+	if n.interp.cancelChan {
+		// Cancellable channel read
+		n.exec = func(f *frame) bltn {
+			ch, result, status := vchan(f), vres(f), vok(f)
+			//  Fast: channel read doesn't block
+			if v, ok := ch.TryRecv(); ok {
+				result.Set(v)
+				status.SetBool(true)
+				return tnext
+			}
+			// Slow: channel is blocked, allow cancel
+			chosen, v, ok := reflect.Select([]reflect.SelectCase{f.done, {Dir: reflect.SelectRecv, Chan: ch}})
+			if chosen == 0 {
+				return nil
+			}
+			result.Set(v)
+			status.SetBool(ok)
+			return tnext
+		}
+	} else {
+		// Blocking channel read (less overhead)
+		n.exec = func(f *frame) bltn {
+			v, ok := vchan(f).Recv()
+			vres(f).Set(v)
+			vok(f).SetBool(ok)
+			return tnext
+		}
 	}
 }
 
 func convertLiteralValue(n *node, t reflect.Type) {
-	if n.kind != basicLit || t == nil || t.Kind() == reflect.Interface {
+	// Skip non-constant values, undefined target type or interface target type.
+	if !(n.kind == basicLit || n.rval.IsValid()) || t == nil || t.Kind() == reflect.Interface {
 		return
 	}
 	if n.rval.IsValid() {
+		// Convert constant value to target type.
 		n.rval = n.rval.Convert(t)
 	} else {
-		n.rval = reflect.New(t).Elem() // convert to type nil value
+		// Create a zero value of target type.
+		n.rval = reflect.New(t).Elem()
 	}
 }
 
@@ -2063,9 +2289,27 @@ func send(n *node) {
 	convertLiteralValue(n.child[1], n.child[0].typ.val.TypeOf())
 	value1 := genValue(n.child[1]) // value to send
 
-	n.exec = func(f *frame) bltn {
-		value0(f).Send(value1(f))
-		return next
+	if n.interp.cancelChan {
+		// Cancellable send
+		n.exec = func(f *frame) bltn {
+			ch, data := value0(f), value1(f)
+			// Fast: send on channel doesn't block
+			if ok := ch.TrySend(data); ok {
+				return next
+			}
+			// Slow: send on channel blocks, allow cancel
+			chosen, _, _ := reflect.Select([]reflect.SelectCase{f.done, {Dir: reflect.SelectSend, Chan: ch, Send: data}})
+			if chosen == 0 {
+				return nil
+			}
+			return next
+		}
+	} else {
+		// Blocking send (less overhead)
+		n.exec = func(f *frame) bltn {
+			value0(f).Send(value1(f))
+			return next
+		}
 	}
 }
 
@@ -2107,7 +2351,7 @@ func _select(n *node) {
 	chanValues := make([]func(*frame) reflect.Value, nbClause)
 	assignedValues := make([]func(*frame) reflect.Value, nbClause)
 	okValues := make([]func(*frame) reflect.Value, nbClause)
-	cases := make([]reflect.SelectCase, nbClause)
+	cases := make([]reflect.SelectCase, nbClause+1)
 
 	for i := 0; i < nbClause; i++ {
 		if len(n.child[i].child) > 1 {
@@ -2127,7 +2371,8 @@ func _select(n *node) {
 	}
 
 	n.exec = func(f *frame) bltn {
-		for i := range cases {
+		cases[nbClause] = f.done
+		for i := range cases[:nbClause] {
 			switch cases[i].Dir {
 			case reflect.SelectRecv:
 				cases[i].Chan = chanValues[i](f)
@@ -2139,6 +2384,9 @@ func _select(n *node) {
 			}
 		}
 		j, v, s := reflect.Select(cases)
+		if j == nbClause {
+			return nil
+		}
 		if cases[j].Dir == reflect.SelectRecv && assignedValues[j] != nil {
 			assignedValues[j](f).Set(v)
 			if ok[j] != nil {
@@ -2215,43 +2463,78 @@ func slice0(n *node) {
 }
 
 func isNil(n *node) {
-	value := genValue(n.child[0])
+	var value func(*frame) reflect.Value
+	if n.child[0].typ.cat == funcT {
+		value = genValueAsFunctionWrapper(n.child[0])
+	} else {
+		value = genValue(n.child[0])
+	}
 	tnext := getExec(n.tnext)
+	dest := genValue(n)
 
 	if n.fnext != nil {
 		fnext := getExec(n.fnext)
 		n.exec = func(f *frame) bltn {
 			if value(f).IsNil() {
+				dest(f).SetBool(true)
 				return tnext
 			}
+			dest(f).SetBool(false)
 			return fnext
 		}
 	} else {
-		i := n.findex
 		n.exec = func(f *frame) bltn {
-			f.data[i].SetBool(value(f).IsNil())
+			dest(f).SetBool(value(f).IsNil())
 			return tnext
 		}
 	}
 }
 
 func isNotNil(n *node) {
-	value := genValue(n.child[0])
+	var value func(*frame) reflect.Value
+	if n.child[0].typ.cat == funcT {
+		value = genValueAsFunctionWrapper(n.child[0])
+	} else {
+		value = genValue(n.child[0])
+	}
 	tnext := getExec(n.tnext)
+	dest := genValue(n)
 
 	if n.fnext != nil {
 		fnext := getExec(n.fnext)
 		n.exec = func(f *frame) bltn {
 			if value(f).IsNil() {
+				dest(f).SetBool(false)
 				return fnext
 			}
+			dest(f).SetBool(true)
 			return tnext
 		}
 	} else {
-		i := n.findex
 		n.exec = func(f *frame) bltn {
-			f.data[i].SetBool(!value(f).IsNil())
+			dest(f).SetBool(!value(f).IsNil())
 			return tnext
 		}
 	}
 }
+
+func complexConst(n *node) {
+	if v0, v1 := n.child[1].rval, n.child[2].rval; v0.IsValid() && v1.IsValid() {
+		n.rval = reflect.ValueOf(complex(vFloat(v0), vFloat(v1)))
+		n.gen = nop
+	}
+}
+
+func imagConst(n *node) {
+	if v := n.child[1].rval; v.IsValid() {
+		n.rval = reflect.ValueOf(imag(v.Complex()))
+		n.gen = nop
+	}
+}
+
+func realConst(n *node) {
+	if v := n.child[1].rval; v.IsValid() {
+		n.rval = reflect.ValueOf(real(v.Complex()))
+		n.gen = nop
+	}
+}

interp/scope.go

@@ -74,12 +74,15 @@ type symbol struct {
 // execution to the index in frame, created exactly from the types layout.
 //
 type scope struct {
-	anc    *scope             // Ancestor upper scope
-	def    *node              // function definition node this scope belongs to, or nil
-	types  []reflect.Type     // Frame layout, may be shared by same level scopes
-	level  int                // Frame level: number of frame indirections to access var during execution
-	sym    map[string]*symbol // Map of symbols defined in this current scope
-	global bool               // true if scope refers to global space (single frame for universe and package level scopes)
+	anc         *scope             // Ancestor upper scope
+	def         *node              // function definition node this scope belongs to, or nil
+	loop        *node              // loop exit node for break statement
+	loopRestart *node              // loop restart node for continue statement
+	pkgID       string             // unique id of package in which scope is defined
+	types       []reflect.Type     // Frame layout, may be shared by same level scopes
+	level       int                // Frame level: number of frame indirections to access var during execution
+	sym         map[string]*symbol // Map of symbols defined in this current scope
+	global      bool               // true if scope refers to global space (single frame for universe and package level scopes)
 }
 
 // push creates a new scope and chain it to the current one
@@ -95,6 +98,8 @@ func (s *scope) push(indirect bool) *scope {
 		sc.global = s.global
 		sc.level = s.level
 	}
+	// inherit loop state and pkgID from ancestor
+	sc.loop, sc.loopRestart, sc.pkgID = s.loop, s.loopRestart, s.pkgID
 	return &sc
 }
 
@@ -156,18 +161,15 @@ func (s *scope) add(typ *itype) (index int) {
 	return
 }
 
-func (interp *Interpreter) initScopePkg(n *node) (*scope, string) {
+func (interp *Interpreter) initScopePkg(pkgID string) *scope {
 	sc := interp.universe
-	pkgName := mainID
 
-	if p := fileNode(n); p != nil {
-		pkgName = p.child[0].ident
+	interp.mutex.Lock()
+	if _, ok := interp.scopes[pkgID]; !ok {
+		interp.scopes[pkgID] = sc.pushBloc()
 	}
-
-	if _, ok := interp.scopes[pkgName]; !ok {
-		interp.scopes[pkgName] = sc.pushBloc()
-	}
-
-	sc = interp.scopes[pkgName]
-	return sc, pkgName
+	sc = interp.scopes[pkgID]
+	sc.pkgID = pkgID
+	interp.mutex.Unlock()
+	return sc
 }

interp/src.go

@@ -8,7 +8,7 @@ import (
 	"strings"
 )
 
-func (interp *Interpreter) importSrc(rPath, path, alias string) error {
+func (interp *Interpreter) importSrc(rPath, path string) error {
 	var dir string
 	var err error
 
@@ -29,6 +29,7 @@ func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 	} else if dir, rPath, err = pkgDir(interp.context.GOPATH, rPath, path); err != nil {
 		return err
 	}
+
 	if interp.rdir[path] {
 		return fmt.Errorf("import cycle not allowed\n\timports %s", path)
 	}
@@ -49,7 +50,7 @@ func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 	// Parse source files
 	for _, file := range files {
 		name := file.Name()
-		if skipFile(interp.context, name) {
+		if skipFile(&interp.context, name) {
 			continue
 		}
 
@@ -66,6 +67,9 @@ func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 		if root == nil {
 			continue
 		}
+		if interp.astDot {
+			root.astDot(dotX(), name)
+		}
 		if pkgName == "" {
 			pkgName = pname
 		} else if pkgName != pname {
@@ -75,7 +79,7 @@ func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 
 		subRPath := effectivePkg(rPath, path)
 		var list []*node
-		list, err = interp.gta(root, subRPath)
+		list, err = interp.gta(root, subRPath, path)
 		if err != nil {
 			return err
 		}
@@ -85,7 +89,7 @@ func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 	// revisit incomplete nodes where GTA could not complete
 	for pkg, nodes := range revisit {
 		for _, n := range nodes {
-			if _, err = interp.gta(n, pkg); err != nil {
+			if _, err = interp.gta(n, pkg, path); err != nil {
 				return err
 			}
 		}
@@ -94,7 +98,7 @@ func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 	// Generate control flow graphs
 	for _, root := range rootNodes {
 		var nodes []*node
-		if nodes, err = interp.cfg(root); err != nil {
+		if nodes, err = interp.cfg(root, path); err != nil {
 			return err
 		}
 		initNodes = append(initNodes, nodes...)
@@ -102,15 +106,13 @@ func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 
 	// Register source package in the interpreter. The package contains only
 	// the global symbols in the package scope.
-	interp.srcPkg[path] = interp.scopes[pkgName].sym
-
-	// Rename imported pkgName to alias if they are different
-	if pkgName != alias {
-		interp.scopes[alias] = interp.scopes[pkgName]
-		delete(interp.scopes, pkgName)
-	}
+	interp.mutex.Lock()
+	interp.srcPkg[path] = interp.scopes[path].sym
 
+	interp.frame.mutex.Lock()
 	interp.resizeFrame()
+	interp.frame.mutex.Unlock()
+	interp.mutex.Unlock()
 
 	// Once all package sources have been parsed, execute entry points then init functions
 	for _, n := range rootNodes {
@@ -185,7 +187,7 @@ func effectivePkg(root, path string) string {
 	for i := 0; i < len(splitPath); i++ {
 		part := splitPath[len(splitPath)-1-i]
 
-		if part == splitRoot[len(splitRoot)-1-rootIndex] {
+		if part == splitRoot[len(splitRoot)-1-rootIndex] && i != 0 {
 			prevRootIndex = rootIndex
 			rootIndex++
 		} else if prevRootIndex == rootIndex {

interp/type.go

@@ -103,30 +103,32 @@ type structField struct {
 
 // itype defines the internal representation of types in the interpreter
 type itype struct {
-	cat        tcat          // Type category
-	field      []structField // Array of struct fields if structT or interfaceT
-	key        *itype        // Type of key element if MapT or nil
-	val        *itype        // Type of value element if chanT, mapT, ptrT, aliasT, arrayT or variadicT
-	arg        []*itype      // Argument types if funcT or nil
-	ret        []*itype      // Return types if funcT or nil
-	method     []*node       // Associated methods or nil
-	name       string        // name of type within its package for a defined type
-	path       string        // for a defined type, the package import path
-	size       int           // Size of array if ArrayT
-	rtype      reflect.Type  // Reflection type if ValueT, or nil
-	incomplete bool          // true if type must be parsed again (out of order declarations)
-	untyped    bool          // true for a literal value (string or number)
-	sizedef    bool          // true if array size is computed from type definition
-	node       *node         // root AST node of type definition
-	scope      *scope        // type declaration scope (in case of re-parse incomplete type)
+	cat         tcat          // Type category
+	field       []structField // Array of struct fields if structT or interfaceT
+	key         *itype        // Type of key element if MapT or nil
+	val         *itype        // Type of value element if chanT, mapT, ptrT, aliasT, arrayT or variadicT
+	arg         []*itype      // Argument types if funcT or nil
+	ret         []*itype      // Return types if funcT or nil
+	method      []*node       // Associated methods or nil
+	name        string        // name of type within its package for a defined type
+	path        string        // for a defined type, the package import path
+	size        int           // Size of array if ArrayT
+	rtype       reflect.Type  // Reflection type if ValueT, or nil
+	incomplete  bool          // true if type must be parsed again (out of order declarations)
+	untyped     bool          // true for a literal value (string or number)
+	sizedef     bool          // true if array size is computed from type definition
+	isBinMethod bool          // true if the type refers to a bin method function
+	node        *node         // root AST node of type definition
+	scope       *scope        // type declaration scope (in case of re-parse incomplete type)
 }
 
 // nodeType returns a type definition for the corresponding AST subtree
 func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
-	var err cfgError
-
 	if n.typ != nil && !n.typ.incomplete {
-		return n.typ, err
+		if n.kind == sliceExpr {
+			n.typ.sizedef = false
+		}
+		return n.typ, nil
 	}
 
 	var t = &itype{node: n, scope: sc}
@@ -141,6 +143,7 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 		}
 	}
 
+	var err cfgError
 	switch n.kind {
 	case addressExpr, starExpr:
 		t.cat = ptrT
@@ -158,7 +161,7 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 				t.size = int(n.child[0].rval.Int())
 			case n.child[0].kind == ellipsisExpr:
 				// [...]T expression
-				t.sizedef = true
+				t.size = arrayTypeLen(n.anc)
 			default:
 				if sym, _, ok := sc.lookup(n.child[0].ident); ok {
 					// Resolve symbol to get size value
@@ -173,7 +176,7 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 					}
 				} else {
 					// Evaluate constant array size expression
-					if _, err = interp.cfg(n.child[0]); err != nil {
+					if _, err = interp.cfg(n.child[0], sc.pkgID); err != nil {
 						return nil, err
 					}
 					t.incomplete = true
@@ -182,6 +185,7 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 			if t.val, err = nodeType(interp, sc, n.child[1]); err != nil {
 				return nil, err
 			}
+			t.sizedef = true
 			t.incomplete = t.incomplete || t.val.incomplete
 		} else {
 			if t.val, err = nodeType(interp, sc, n.child[0]); err != nil {
@@ -285,6 +289,9 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 					default:
 						err = n.cfgErrorf("invalid types %s and %s", t0.Kind(), t1.Kind())
 					}
+					if nt0.untyped && nt1.untyped {
+						t.untyped = true
+					}
 				}
 			case "real", "imag":
 				if t, err = nodeType(interp, sc, n.child[1]); err != nil {
@@ -297,7 +304,7 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 					case k == reflect.Complex128:
 						t = sc.getType("float64")
 					case t.untyped && isNumber(t.TypeOf()):
-						t = &itype{cat: valueT, rtype: floatType}
+						t = &itype{cat: valueT, rtype: floatType, untyped: true}
 					default:
 						err = n.cfgErrorf("invalid complex type %s", k)
 					}
@@ -395,6 +402,9 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 				t.method = m
 				sym.typ = t
 			}
+			if t.node == nil {
+				t.node = n
+			}
 		} else {
 			t.incomplete = true
 			sc.sym[n.ident] = &symbol{kind: typeSym, typ: t}
@@ -473,7 +483,7 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 			if m, _ := lt.lookupMethod(name); m != nil {
 				t, err = nodeType(interp, sc, m.child[2])
 			} else if bm, _, _, ok := lt.lookupBinMethod(name); ok {
-				t = &itype{cat: valueT, rtype: bm.Type}
+				t = &itype{cat: valueT, rtype: bm.Type, isBinMethod: true}
 			} else if ti := lt.lookupField(name); len(ti) > 0 {
 				t = lt.fieldSeq(ti)
 			} else if bs, _, ok := lt.lookupBinField(name); ok {
@@ -483,6 +493,18 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 			}
 		}
 
+	case sliceExpr:
+		t, err = nodeType(interp, sc, n.child[0])
+		if t.cat == ptrT {
+			t = t.val
+		}
+		if err == nil && t.size != 0 {
+			t1 := *t
+			t1.size = 0
+			t1.rtype = nil
+			t = &t1
+		}
+
 	case structType:
 		t.cat = structT
 		var incomplete bool
@@ -618,6 +640,74 @@ func (t *itype) finalize() (*itype, error) {
 	return t, err
 }
 
+// Equals returns true if the given type is identical to the receiver one.
+func (t *itype) equals(o *itype) bool {
+	switch ti, oi := isInterface(t), isInterface(o); {
+	case ti && oi:
+		return t.methods().equals(o.methods())
+	case ti && !oi:
+		return o.methods().contains(t.methods())
+	case oi && !ti:
+		return t.methods().contains(o.methods())
+	default:
+		return t.id() == o.id()
+	}
+}
+
+// MethodSet defines the set of methods signatures as strings, indexed per method name.
+type methodSet map[string]string
+
+// Contains returns true if the method set m contains the method set n.
+func (m methodSet) contains(n methodSet) bool {
+	for k, v := range n {
+		if m[k] != v {
+			return false
+		}
+	}
+	return true
+}
+
+// Equal returns true if the method set m is equal to the method set n.
+func (m methodSet) equals(n methodSet) bool {
+	return m.contains(n) && n.contains(m)
+}
+
+// Methods returns a map of method type strings, indexed by method names.
+func (t *itype) methods() methodSet {
+	res := make(methodSet)
+	switch t.cat {
+	case interfaceT:
+		// Get methods from recursive analysis of interface fields
+		for _, f := range t.field {
+			if f.typ.cat == funcT {
+				res[f.name] = f.typ.TypeOf().String()
+			} else {
+				for k, v := range f.typ.methods() {
+					res[k] = v
+				}
+			}
+		}
+	case valueT, errorT:
+		// Get method from corresponding reflect.Type
+		for i := t.rtype.NumMethod() - 1; i >= 0; i-- {
+			m := t.rtype.Method(i)
+			res[m.Name] = m.Type.String()
+		}
+	case ptrT:
+		// Consider only methods where receiver is a pointer to type t
+		for _, m := range t.val.method {
+			if m.child[0].child[0].lastChild().typ.cat == ptrT {
+				res[m.ident] = m.typ.TypeOf().String()
+			}
+		}
+	default:
+		for _, m := range t.method {
+			res[m.ident] = m.typ.TypeOf().String()
+		}
+	}
+	return res
+}
+
 // id returns a unique type identificator string
 func (t *itype) id() string {
 	// TODO: if res is nil, build identity from String()
@@ -720,6 +810,22 @@ func (t *itype) lookupBinField(name string) (s reflect.StructField, index []int,
 	return s, index, ok
 }
 
+// methodCallType returns a method function type without the receiver defined.
+// The input type must be a method function type with the receiver as the first input argument.
+func (t *itype) methodCallType() reflect.Type {
+	it := []reflect.Type{}
+	ni := t.rtype.NumIn()
+	for i := 1; i < ni; i++ {
+		it = append(it, t.rtype.In(i))
+	}
+	ot := []reflect.Type{}
+	no := t.rtype.NumOut()
+	for i := 0; i < no; i++ {
+		ot = append(ot, t.rtype.Out(i))
+	}
+	return reflect.FuncOf(it, ot, t.rtype.IsVariadic())
+}
+
 // getMethod returns a pointer to the method definition
 func (t *itype) getMethod(name string) *node {
 	for _, m := range t.method {
@@ -796,14 +902,16 @@ func (t *itype) refType(defined map[string]bool) reflect.Type {
 			panic(err)
 		}
 	}
-	if t.val != nil && defined[t.val.name] {
+	if t.val != nil && defined[t.val.name] && !t.val.incomplete && t.val.rtype == nil {
+		// Replace reference to self (direct or indirect) by an interface{} to handle
+		// recursive types with reflect.
 		t.val.rtype = interf
 	}
 	switch t.cat {
 	case aliasT:
 		t.rtype = t.val.refType(defined)
 	case arrayT, variadicT:
-		if t.size > 0 {
+		if t.sizedef {
 			t.rtype = reflect.ArrayOf(t.size, t.val.refType(defined))
 		} else {
 			t.rtype = reflect.SliceOf(t.val.refType(defined))
@@ -816,22 +924,16 @@ func (t *itype) refType(defined map[string]bool) reflect.Type {
 		in := make([]reflect.Type, len(t.arg))
 		out := make([]reflect.Type, len(t.ret))
 		for i, v := range t.arg {
-			if defined[v.name] {
-				v.rtype = interf
-			}
 			in[i] = v.refType(defined)
 		}
 		for i, v := range t.ret {
-			if defined[v.name] {
-				v.rtype = interf
-			}
 			out[i] = v.refType(defined)
 		}
 		t.rtype = reflect.FuncOf(in, out, false)
 	case interfaceT:
 		t.rtype = interf
 	case mapT:
-		t.rtype = reflect.MapOf(t.key.TypeOf(), t.val.TypeOf())
+		t.rtype = reflect.MapOf(t.key.refType(defined), t.val.refType(defined))
 	case ptrT:
 		t.rtype = reflect.PtrTo(t.val.refType(defined))
 	case structT:
@@ -866,7 +968,7 @@ func (t *itype) frameType() (r reflect.Type) {
 	case aliasT:
 		r = t.val.frameType()
 	case arrayT, variadicT:
-		if t.size > 0 {
+		if t.sizedef {
 			r = reflect.ArrayOf(t.size, t.val.frameType())
 		} else {
 			r = reflect.SliceOf(t.val.frameType())
@@ -915,7 +1017,13 @@ func isInterface(t *itype) bool {
 	return isInterfaceSrc(t) || t.TypeOf().Kind() == reflect.Interface
 }
 
-func isStruct(t *itype) bool { return t.TypeOf().Kind() == reflect.Struct }
+func isStruct(t *itype) bool {
+	// Test first for a struct category, because a recursive interpreter struct may be
+	// represented by an interface{} at reflect level.
+	return t.cat == structT || t.TypeOf().Kind() == reflect.Struct
+}
+
+func isBool(t *itype) bool { return t.TypeOf().Kind() == reflect.Bool }
 
 func isInt(t reflect.Type) bool {
 	switch t.Kind() {

interp/value.go

@@ -7,21 +7,31 @@ import (
 func valueGenerator(n *node, i int) func(*frame) reflect.Value {
 	switch n.level {
 	case 0:
-		return func(f *frame) reflect.Value { return f.data[i] }
+		return func(f *frame) reflect.Value { return valueOf(f.data, i) }
 	case 1:
-		return func(f *frame) reflect.Value { return f.anc.data[i] }
+		return func(f *frame) reflect.Value { return valueOf(f.anc.data, i) }
 	case 2:
-		return func(f *frame) reflect.Value { return f.anc.anc.data[i] }
+		return func(f *frame) reflect.Value { return valueOf(f.anc.anc.data, i) }
 	default:
 		return func(f *frame) reflect.Value {
 			for level := n.level; level > 0; level-- {
 				f = f.anc
 			}
-			return f.data[i]
+			return valueOf(f.data, i)
 		}
 	}
 }
 
+// valueOf safely recovers the ith element of data. This is necessary
+// because a cancellation prior to any evaluation result may leave
+// the frame's data empty.
+func valueOf(data []reflect.Value, i int) reflect.Value {
+	if i < len(data) {
+		return data[i]
+	}
+	return reflect.Value{}
+}
+
 func genValueRecvIndirect(n *node) func(*frame) reflect.Value {
 	v := genValueRecv(n)
 	return func(f *frame) reflect.Value { return v(f).Elem() }
@@ -45,9 +55,15 @@ func genValueRecv(n *node) func(*frame) reflect.Value {
 }
 
 func genValueAsFunctionWrapper(n *node) func(*frame) reflect.Value {
-	v := genValue(n)
+	value := genValue(n)
+	typ := n.typ.TypeOf()
+
 	return func(f *frame) reflect.Value {
-		return genFunctionWrapper(v(f).Interface().(*node))(f)
+		v := value(f)
+		if v.IsNil() {
+			return reflect.New(typ).Elem()
+		}
+		return genFunctionWrapper(v.Interface().(*node))(f)
 	}
 }
 
@@ -118,6 +134,22 @@ func genValueArray(n *node) func(*frame) reflect.Value {
 	return value
 }
 
+func genValueRangeArray(n *node) func(*frame) reflect.Value {
+	value := genValue(n)
+	// dereference array pointer, to support array operations on array pointer
+	if n.typ.TypeOf().Kind() == reflect.Ptr {
+		return func(f *frame) reflect.Value {
+			return value(f).Elem()
+		}
+	}
+	return func(f *frame) reflect.Value {
+		// This is necessary to prevent changes in the returned
+		// reflect.Value being reflected back to the value used
+		// for the range expression.
+		return reflect.ValueOf(value(f).Interface())
+	}
+}
+
 func genValueInterfacePtr(n *node) func(*frame) reflect.Value {
 	value := genValue(n)
 	it := reflect.TypeOf((*interface{})(nil)).Elem()
@@ -133,15 +165,46 @@ func genValueInterface(n *node) func(*frame) reflect.Value {
 	value := genValue(n)
 
 	return func(f *frame) reflect.Value {
-		return reflect.ValueOf(valueInterface{n, value(f)})
+		v := value(f)
+		nod := n
+		for {
+			// traverse interface indirections to find out concrete type
+			vi, ok := v.Interface().(valueInterface)
+			if !ok {
+				break
+			}
+			v = vi.value
+			nod = vi.node
+		}
+		return reflect.ValueOf(valueInterface{nod, v})
 	}
 }
 
+func zeroInterfaceValue() reflect.Value {
+	n := &node{kind: basicLit, typ: &itype{cat: nilT, untyped: true}}
+	v := reflect.New(reflect.TypeOf((*interface{})(nil)).Elem()).Elem()
+	return reflect.ValueOf(valueInterface{n, v})
+}
+
 func genValueInterfaceValue(n *node) func(*frame) reflect.Value {
 	value := genValue(n)
 
 	return func(f *frame) reflect.Value {
-		return value(f).Interface().(valueInterface).value
+		v := value(f)
+		if v.Interface().(valueInterface).node == nil {
+			// Uninitialized interface value, set it to a correct zero value.
+			v.Set(zeroInterfaceValue())
+			v = value(f)
+		}
+		return v.Interface().(valueInterface).value
+	}
+}
+
+func genValueNode(n *node) func(*frame) reflect.Value {
+	value := genValue(n)
+
+	return func(f *frame) reflect.Value {
+		return reflect.ValueOf(&node{rval: value(f)})
 	}
 }
 
@@ -153,6 +216,8 @@ func vInt(v reflect.Value) (i int64) {
 		i = int64(v.Uint())
 	case reflect.Float32, reflect.Float64:
 		i = int64(v.Float())
+	case reflect.Complex64, reflect.Complex128:
+		i = int64(real(v.Complex()))
 	}
 	return
 }
@@ -165,6 +230,8 @@ func vUint(v reflect.Value) (i uint64) {
 		i = v.Uint()
 	case reflect.Float32, reflect.Float64:
 		i = uint64(v.Float())
+	case reflect.Complex64, reflect.Complex128:
+		i = uint64(real(v.Complex()))
 	}
 	return
 }
@@ -191,6 +258,8 @@ func vFloat(v reflect.Value) (i float64) {
 		i = float64(v.Uint())
 	case reflect.Float32, reflect.Float64:
 		i = v.Float()
+	case reflect.Complex64, reflect.Complex128:
+		i = real(v.Complex())
 	}
 	return
 }
@@ -205,6 +274,10 @@ func genValueInt(n *node) func(*frame) (reflect.Value, int64) {
 		return func(f *frame) (reflect.Value, int64) { v := value(f); return v, int64(v.Uint()) }
 	case reflect.Float32, reflect.Float64:
 		return func(f *frame) (reflect.Value, int64) { v := value(f); return v, int64(v.Float()) }
+	case reflect.Complex64, reflect.Complex128:
+		if n.typ.untyped && n.rval.IsValid() && imag(n.rval.Complex()) == 0 {
+			return func(f *frame) (reflect.Value, int64) { v := value(f); return v, int64(real(v.Complex())) }
+		}
 	}
 	return nil
 }
@@ -219,6 +292,10 @@ func genValueUint(n *node) func(*frame) (reflect.Value, uint64) {
 		return func(f *frame) (reflect.Value, uint64) { v := value(f); return v, v.Uint() }
 	case reflect.Float32, reflect.Float64:
 		return func(f *frame) (reflect.Value, uint64) { v := value(f); return v, uint64(v.Float()) }
+	case reflect.Complex64, reflect.Complex128:
+		if n.typ.untyped && n.rval.IsValid() && imag(n.rval.Complex()) == 0 {
+			return func(f *frame) (reflect.Value, uint64) { v := value(f); return v, uint64(real(v.Complex())) }
+		}
 	}
 	return nil
 }
@@ -233,22 +310,31 @@ func genValueFloat(n *node) func(*frame) (reflect.Value, float64) {
 		return func(f *frame) (reflect.Value, float64) { v := value(f); return v, float64(v.Uint()) }
 	case reflect.Float32, reflect.Float64:
 		return func(f *frame) (reflect.Value, float64) { v := value(f); return v, v.Float() }
+	case reflect.Complex64, reflect.Complex128:
+		if n.typ.untyped && n.rval.IsValid() && imag(n.rval.Complex()) == 0 {
+			return func(f *frame) (reflect.Value, float64) { v := value(f); return v, real(v.Complex()) }
+		}
 	}
 	return nil
 }
 
-func genValueComplex(n *node) func(*frame) (reflect.Value, complex128) {
+func genValueComplex(n *node) func(*frame) reflect.Value {
+	vc := genComplex(n)
+	return func(f *frame) reflect.Value { return reflect.ValueOf(vc(f)) }
+}
+
+func genComplex(n *node) func(*frame) complex128 {
 	value := genValue(n)
 
 	switch n.typ.TypeOf().Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		return func(f *frame) (reflect.Value, complex128) { v := value(f); return v, complex(float64(v.Int()), 0) }
+		return func(f *frame) complex128 { return complex(float64(value(f).Int()), 0) }
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		return func(f *frame) (reflect.Value, complex128) { v := value(f); return v, complex(float64(v.Uint()), 0) }
+		return func(f *frame) complex128 { return complex(float64(value(f).Uint()), 0) }
 	case reflect.Float32, reflect.Float64:
-		return func(f *frame) (reflect.Value, complex128) { v := value(f); return v, complex(v.Float(), 0) }
+		return func(f *frame) complex128 { return complex(value(f).Float(), 0) }
 	case reflect.Complex64, reflect.Complex128:
-		return func(f *frame) (reflect.Value, complex128) { v := value(f); return v, v.Complex() }
+		return func(f *frame) complex128 { return value(f).Complex() }
 	}
 	return nil
 }

stdlib/go1_11_archive_tar.go

@@ -1,47 +0,0 @@
-// Code generated by 'goexports archive/tar'. DO NOT EDIT.
-
-// +build go1.11,!go1.12
-
-package stdlib
-
-import (
-	"archive/tar"
-	"reflect"
-)
-
-func init() {
-	Symbols["archive/tar"] = map[string]reflect.Value{
-		// function, constant and variable definitions
-		"ErrFieldTooLong":    reflect.ValueOf(&tar.ErrFieldTooLong).Elem(),
-		"ErrHeader":          reflect.ValueOf(&tar.ErrHeader).Elem(),
-		"ErrWriteAfterClose": reflect.ValueOf(&tar.ErrWriteAfterClose).Elem(),
-		"ErrWriteTooLong":    reflect.ValueOf(&tar.ErrWriteTooLong).Elem(),
-		"FileInfoHeader":     reflect.ValueOf(tar.FileInfoHeader),
-		"FormatGNU":          reflect.ValueOf(tar.FormatGNU),
-		"FormatPAX":          reflect.ValueOf(tar.FormatPAX),
-		"FormatUSTAR":        reflect.ValueOf(tar.FormatUSTAR),
-		"FormatUnknown":      reflect.ValueOf(tar.FormatUnknown),
-		"NewReader":          reflect.ValueOf(tar.NewReader),
-		"NewWriter":          reflect.ValueOf(tar.NewWriter),
-		"TypeBlock":          reflect.ValueOf(tar.TypeBlock),
-		"TypeChar":           reflect.ValueOf(tar.TypeChar),
-		"TypeCont":           reflect.ValueOf(tar.TypeCont),
-		"TypeDir":            reflect.ValueOf(tar.TypeDir),
-		"TypeFifo":           reflect.ValueOf(tar.TypeFifo),
-		"TypeGNULongLink":    reflect.ValueOf(tar.TypeGNULongLink),
-		"TypeGNULongName":    reflect.ValueOf(tar.TypeGNULongName),
-		"TypeGNUSparse":      reflect.ValueOf(tar.TypeGNUSparse),
-		"TypeLink":           reflect.ValueOf(tar.TypeLink),
-		"TypeReg":            reflect.ValueOf(tar.TypeReg),
-		"TypeRegA":           reflect.ValueOf(tar.TypeRegA),
-		"TypeSymlink":        reflect.ValueOf(tar.TypeSymlink),
-		"TypeXGlobalHeader":  reflect.ValueOf(tar.TypeXGlobalHeader),
-		"TypeXHeader":        reflect.ValueOf(tar.TypeXHeader),
-
-		// type definitions
-		"Format": reflect.ValueOf((*tar.Format)(nil)),
-		"Header": reflect.ValueOf((*tar.Header)(nil)),
-		"Reader": reflect.ValueOf((*tar.Reader)(nil)),
-		"Writer": reflect.ValueOf((*tar.Writer)(nil)),
-	}
-}

stdlib/go1_11_archive_zip.go

@@ -1,36 +0,0 @@
-// Code generated by 'goexports archive/zip'. DO NOT EDIT.
-
-// +build go1.11,!go1.12
-
-package stdlib
-
-import (
-	"archive/zip"
-	"reflect"
-)
-
-func init() {
-	Symbols["archive/zip"] = map[string]reflect.Value{
-		// function, constant and variable definitions
-		"Deflate":              reflect.ValueOf(zip.Deflate),
-		"ErrAlgorithm":         reflect.ValueOf(&zip.ErrAlgorithm).Elem(),
-		"ErrChecksum":          reflect.ValueOf(&zip.ErrChecksum).Elem(),
-		"ErrFormat":            reflect.ValueOf(&zip.ErrFormat).Elem(),
-		"FileInfoHeader":       reflect.ValueOf(zip.FileInfoHeader),
-		"NewReader":            reflect.ValueOf(zip.NewReader),
-		"NewWriter":            reflect.ValueOf(zip.NewWriter),
-		"OpenReader":           reflect.ValueOf(zip.OpenReader),
-		"RegisterCompressor":   reflect.ValueOf(zip.RegisterCompressor),
-		"RegisterDecompressor": reflect.ValueOf(zip.RegisterDecompressor),
-		"Store":                reflect.ValueOf(zip.Store),
-
-		// type definitions
-		"Compressor":   reflect.ValueOf((*zip.Compressor)(nil)),
-		"Decompressor": reflect.ValueOf((*zip.Decompressor)(nil)),
-		"File":         reflect.ValueOf((*zip.File)(nil)),
-		"FileHeader":   reflect.ValueOf((*zip.FileHeader)(nil)),
-		"ReadCloser":   reflect.ValueOf((*zip.ReadCloser)(nil)),
-		"Reader":       reflect.ValueOf((*zip.Reader)(nil)),
-		"Writer":       reflect.ValueOf((*zip.Writer)(nil)),
-	}
-}

stdlib/go1_11_bufio.go

@@ -1,42 +0,0 @@
-// Code generated by 'goexports bufio'. DO NOT EDIT.
-
-// +build go1.11,!go1.12
-
-package stdlib
-
-import (
-	"bufio"
-	"reflect"
-)
-
-func init() {
-	Symbols["bufio"] = map[string]reflect.Value{
-		// function, constant and variable definitions
-		"ErrAdvanceTooFar":     reflect.ValueOf(&bufio.ErrAdvanceTooFar).Elem(),
-		"ErrBufferFull":        reflect.ValueOf(&bufio.ErrBufferFull).Elem(),
-		"ErrFinalToken":        reflect.ValueOf(&bufio.ErrFinalToken).Elem(),
-		"ErrInvalidUnreadByte": reflect.ValueOf(&bufio.ErrInvalidUnreadByte).Elem(),
-		"ErrInvalidUnreadRune": reflect.ValueOf(&bufio.ErrInvalidUnreadRune).Elem(),
-		"ErrNegativeAdvance":   reflect.ValueOf(&bufio.ErrNegativeAdvance).Elem(),
-		"ErrNegativeCount":     reflect.ValueOf(&bufio.ErrNegativeCount).Elem(),
-		"ErrTooLong":           reflect.ValueOf(&bufio.ErrTooLong).Elem(),
-		"MaxScanTokenSize":     reflect.ValueOf(bufio.MaxScanTokenSize),
-		"NewReadWriter":        reflect.ValueOf(bufio.NewReadWriter),
-		"NewReader":            reflect.ValueOf(bufio.NewReader),
-		"NewReaderSize":        reflect.ValueOf(bufio.NewReaderSize),
-		"NewScanner":           reflect.ValueOf(bufio.NewScanner),
-		"NewWriter":            reflect.ValueOf(bufio.NewWriter),
-		"NewWriterSize":        reflect.ValueOf(bufio.NewWriterSize),
-		"ScanBytes":            reflect.ValueOf(bufio.ScanBytes),
-		"ScanLines":            reflect.ValueOf(bufio.ScanLines),
-		"ScanRunes":            reflect.ValueOf(bufio.ScanRunes),
-		"ScanWords":            reflect.ValueOf(bufio.ScanWords),
-
-		// type definitions
-		"ReadWriter": reflect.ValueOf((*bufio.ReadWriter)(nil)),
-		"Reader":     reflect.ValueOf((*bufio.Reader)(nil)),
-		"Scanner":    reflect.ValueOf((*bufio.Scanner)(nil)),
-		"SplitFunc":  reflect.ValueOf((*bufio.SplitFunc)(nil)),
-		"Writer":     reflect.ValueOf((*bufio.Writer)(nil)),
-	}
-}

stdlib/go1_11_bytes.go

@@ -1,70 +0,0 @@
-// Code generated by 'goexports bytes'. DO NOT EDIT.
-
-// +build go1.11,!go1.12
-
-package stdlib
-
-import (
-	"bytes"
-	"reflect"
-)
-
-func init() {
-	Symbols["bytes"] = map[string]reflect.Value{
-		// function, constant and variable definitions
-		"Compare":         reflect.ValueOf(bytes.Compare),
-		"Contains":        reflect.ValueOf(bytes.Contains),
-		"ContainsAny":     reflect.ValueOf(bytes.ContainsAny),
-		"ContainsRune":    reflect.ValueOf(bytes.ContainsRune),
-		"Count":           reflect.ValueOf(bytes.Count),
-		"Equal":           reflect.ValueOf(bytes.Equal),
-		"EqualFold":       reflect.ValueOf(bytes.EqualFold),
-		"ErrTooLarge":     reflect.ValueOf(&bytes.ErrTooLarge).Elem(),
-		"Fields":          reflect.ValueOf(bytes.Fields),
-		"FieldsFunc":      reflect.ValueOf(bytes.FieldsFunc),
-		"HasPrefix":       reflect.ValueOf(bytes.HasPrefix),
-		"HasSuffix":       reflect.ValueOf(bytes.HasSuffix),
-		"Index":           reflect.ValueOf(bytes.Index),
-		"IndexAny":        reflect.ValueOf(bytes.IndexAny),
-		"IndexByte":       reflect.ValueOf(bytes.IndexByte),
-		"IndexFunc":       reflect.ValueOf(bytes.IndexFunc),
-		"IndexRune":       reflect.ValueOf(bytes.IndexRune),
-		"Join":            reflect.ValueOf(bytes.Join),
-		"LastIndex":       reflect.ValueOf(bytes.LastIndex),
-		"LastIndexAny":    reflect.ValueOf(bytes.LastIndexAny),
-		"LastIndexByte":   reflect.ValueOf(bytes.LastIndexByte),
-		"LastIndexFunc":   reflect.ValueOf(bytes.LastIndexFunc),
-		"Map":             reflect.ValueOf(bytes.Map),
-		"MinRead":         reflect.ValueOf(bytes.MinRead),
-		"NewBuffer":       reflect.ValueOf(bytes.NewBuffer),
-		"NewBufferString": reflect.ValueOf(bytes.NewBufferString),
-		"NewReader":       reflect.ValueOf(bytes.NewReader),
-		"Repeat":          reflect.ValueOf(bytes.Repeat),
-		"Replace":         reflect.ValueOf(bytes.Replace),
-		"Runes":           reflect.ValueOf(bytes.Runes),
-		"Split":           reflect.ValueOf(bytes.Split),
-		"SplitAfter":      reflect.ValueOf(bytes.SplitAfter),
-		"SplitAfterN":     reflect.ValueOf(bytes.SplitAfterN),
-		"SplitN":          reflect.ValueOf(bytes.SplitN),
-		"Title":           reflect.ValueOf(bytes.Title),
-		"ToLower":         reflect.ValueOf(bytes.ToLower),
-		"ToLowerSpecial":  reflect.ValueOf(bytes.ToLowerSpecial),
-		"ToTitle":         reflect.ValueOf(bytes.ToTitle),
-		"ToTitleSpecial":  reflect.ValueOf(bytes.ToTitleSpecial),
-		"ToUpper":         reflect.ValueOf(bytes.ToUpper),
-		"ToUpperSpecial":  reflect.ValueOf(bytes.ToUpperSpecial),
-		"Trim":            reflect.ValueOf(bytes.Trim),
-		"TrimFunc":        reflect.ValueOf(bytes.TrimFunc),
-		"TrimLeft":        reflect.ValueOf(bytes.TrimLeft),
-		"TrimLeftFunc":    reflect.ValueOf(bytes.TrimLeftFunc),
-		"TrimPrefix":      reflect.ValueOf(bytes.TrimPrefix),
-		"TrimRight":       reflect.ValueOf(bytes.TrimRight),
-		"TrimRightFunc":   reflect.ValueOf(bytes.TrimRightFunc),
-		"TrimSpace":       reflect.ValueOf(bytes.TrimSpace),
-		"TrimSuffix":      reflect.ValueOf(bytes.TrimSuffix),
-
-		// type definitions
-		"Buffer": reflect.ValueOf((*bytes.Buffer)(nil)),
-		"Reader": reflect.ValueOf((*bytes.Reader)(nil)),
-	}
-}