Fix handling map boolean values

_test/bool3.go

@@ -0,0 +1,13 @@
+package main
+
+func main() {
+	m := map[int]bool{0: false, 1: true}
+	if m[0] {
+		println(0)
+	} else {
+		println(1)
+	}
+}
+
+// Output:
+// 1

interp/interp_test.go

@@ -613,6 +613,26 @@ func main() {
 	// nok
 }
 
+func Example_bool3() {
+	src := `
+package main
+
+func main() {
+	m := map[int]bool{0: false, 1: true}
+	if m[0] {
+		println(0)
+	} else {
+		println(1)
+	}
+}
+`
+	i := NewInterpreter(Opt{Entry: "main"}, "bool3.go")
+	i.Eval(src)
+
+	// Output:
+	// 1
+}
+
 func Example_chan0() {
 	src := `
 package main

interp/run.go

@@ -565,14 +565,24 @@ func getIndexArray(n *Node) {
 
 // getIndexMap retrieves map value from index
 func getIndexMap(n *Node) {
-	i := n.findex
 	value0 := genValue(n.child[0]) // map
 	value1 := genValue(n.child[1]) // index
-	next := getExec(n.tnext)
+	tnext := getExec(n.tnext)
 
-	n.exec = func(f *Frame) Builtin {
-		f.data[i] = value0(f).MapIndex(value1(f))
-		return next
+	if n.fnext != nil {
+		fnext := getExec(n.fnext)
+		n.exec = func(f *Frame) Builtin {
+			if value0(f).MapIndex(value1(f)).Bool() {
+				return tnext
+			}
+			return fnext
+		}
+	} else {
+		i := n.findex
+		n.exec = func(f *Frame) Builtin {
+			f.data[i] = value0(f).MapIndex(value1(f))
+			return tnext
+		}
 	}
 }