As the unsafe and pointer methods in `reflect` are to be depreciated, and seeing no replacement functions, it is now forced that some unsafe is needed to replace this as when and interface is dereferenced it is made unsettable by reflect.
With this in mind, this adds real recursive types by hot swapping the struct field type on the fly. This removes a lot of compensation code, simplifying all previous cases.
**Note:** While the struct field type is swapped for the real type, the type string is not changed. Due to this, unsafe will recreate the same type.
This adds `itype.str` which is a string representation of the type built when the type is built. The goal is to make type comparison simpler and centralise the creation of types just to constructors and `nodeType`. `nodeType` continues to build types in parts so to reuse underlying types better.
Add getConcreteType to retrieve the concrete type of a nested interface
value implementing a specific interface for which a wrapper exists.
If method resolution fails at runtime, a panic is now issued instead
of an error message and continue.
Fixes#1187.
In typecheck.go, detect binary methods so we know when to skip the receiver as first parameter when checking function signatures. The signature check is not yet performed, we just avoid a false error.
In cfg.go, take care to label types with isBinMethod field to true whenever a binary method is resolved.
Also, do not attempt to wrap node in functions if the node value is already a binary function.
Fixes#1145.
The case of assigning a binary function to a funcT object was
solved elsewhere. Factor the case in genDestValue to apply it
at multiple places.
Fixes#1100.
Functions in a struct fields are always wrapped (as potentially
used by the runtime), so generate a function wrapper also for
closure when assigned to a struct field.
When such a function is called from the interpreter, ensure that
interface arguments are also wrapped so method and receiver resolution
can be performed.
Fixes partially #1043.
The empty interface (interface{}), and its variants (such as []interface{} and map[string]interface{}), are commonly used in Go to (json) Unmarshal arbitrary data. Within Yaegi, all interface types are wrapped in a valueInterface struct in order to retain all the information needed for a consistent internal state (as reflect is not enough to achieve that). However, this wrapping ends up being problematic when it comes to the type assertions related to the aforementioned Unmarshaling.
Therefore, this PR is an attempt to consider the empty interface (and its variants) as an exception within Yaegi, that should never be wrapped within a valueInterface, and to treat it similarly to the other basic Go types. The assumption is that the wrapping should not be needed, as there is no information about implemented methods to maintain.
Fixes#984Fixes#829Fixes#1015
In some cases, the global character of a value was lost, leading to
undefined behaviour. Now a node level field of -1 means that the value
is global, and that it should be accessed from the root data frame.
Fixes#993.
The interpreter interface type was replaced by a reflect.Value in
objects passed or return to function wrappers, losing the ability
to retrieve methods.
The valueInterface is now preserved, and correctly accessed if
wrapped multiple times.
Fixes#977.
The function vUint, used to get the unsigned integer value of a value,
variable (frame) or constant, was broken for constant.Value expression.
Fixes#948.
This adds type checking to CallExpr (excluding builtin type checking, as that is a PR in its own right) as well as handling any required constant type conversion.
This also changes constant strings and runes to be represented as `constant.Value`. Runes change `rval` type at CFG typing time to avoid having to type at AST time. There are also changes to importSpecs and `stdlib` to account for the string change. With this all `untyped` types should now be `constant.Value`s, although errors are still not returned if this is not the case to be sure we do not break things.
This also fixed a bug in `itype.methods` that would panic if the type was recursive.
This adds type checking to both `IndexExpr` and `CompositeLitExpr` as well as handling any required constant type conversion.
This includes a change to the type propagation to the children of a composite literal. Previously in most cases the composite literal type was propagated to its children. This does not work with type checking as the actual child type is needed.
* fix: copy the type in recursion
In more advanced recursive cases, setting the rtype to interface may interfear with typeing. To stop this from happening, instead of setting t.val.rtype to interface in the hope it will be set correctly later, a copy if the type is made, and the rtype of the copy is set to interface{}.
* fix: detect intermediate recursive structs
In the case of a nested recussion, each symbol can have
a different perspective on the recursion. In this case,
it is impossible to move from one struct to the next.
To keep the perspectives the same, any intermediate struct
that contains a recursion should also be set to interface{}.
so that all perspectives are the same.
* fix: handle arb recursion
* chore: refactor dref to be consistent
* fix: invalid recursive struct issue
* fix: handle checkptr issue
* fix: move unsafe into function to stop ptr check
* fix: handle deref in assign
* fix: make interpreter methods discoverable by runtime
When generating an interface wrapper, lookup existing wrappers by method
to get the one with the biggest set of methods implemented by interpreter.
A string method is also added to wrappers, in order to provide a string
representation of the interpreter value rather than the wrapper itself
(at least for %s and %v verbs).
This allows the runtime to pickup an interpreter method automatically
even if the conversion to the interface is not specified in the script. As
in Go spec, it is enough for the type to implement the required methods.
A current limitation is that only single wrappers can be instantiated,
not allowing to compose interfaces.
This limitation can be removed when the Go reflect issue
https://github.com/golang/go/issues/15924 is fixed.
Fixes#435.
* test: add a simpler test
* feat: add support for named output variables
Function output parameters are located at the start of the function
frame, uninitialized, as they could be only set through return
statements.
Supporting named output variables requires to:
- identify and allocate symbols corresponding to output names:
done at ident parsing, with the funcRet() helper,
- compute the location of output name in the frame:
done with retRank() helper,
- initialize the frame entry with the zero value of symbol type,
as the symbol can be accessed and written at multiple times,
and return not setting the variable (opposite to unnamed).
Done with frameType() helper, which now takes into account
output parameters.
* refactor: simplify memory management
Perform function frame analysis at pre-order, instead of post-order, to
initialize memory frame, and track value types. Remove all operation
involving unitialized types. Frame memory layout is now build
incrementally, instead of having to perform dedicated tree walks on AST.
Eval returns the value of the root node of AST, so ensure
that node values are propagated back to ExprStmt and BlockStmt,
which should be sufficient to handle evaluation of simple
statements.
Change the way imported binary variables are imported, from
`reflect.ValueOf(val)` to `reflect.ValueOf(&val).Elem()`, to allow these
variables to be set from the interpreter.
Regenerate stdlib packages accordingly.
Ensure that binary value is forwarded if it exists.
Add tests.
The code for comparison operators is now generated by genop.
The support for multiple type has been added.
Missing operators <= and >= are now implemented.
