* fix: untyped constant cconverson to default type
In definition assign expression, the source type is propagated to
the assigned value. If the source is an untyped constant, the
destination type must be set to the default type of the constant
definition. A fixType function is provided to perform this.
In addition, the type conversion and check of constants is
refactored for simplifications.
Fixes#727.
* test: fix _test/const14.go
* 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
* fix: finish support of type assertions which was incomplete
TypeAssert was optimistically returning ok without verifying that
value could be converted to the required interface (in case of
type assert of an interface type), or not checking the type in
all conditions. There is now a working implements method for itype.
Fixes#640.
* style: appease lint
* fix: remove useless code block
* doc: improve comments
* avoid test conflict
* fix: use interface wrappers to expose interface values to runtime
If a value is assigned to, or returned as, a binary interface,
then use the interface wrapper generator to convert the value
accordingly.
Fixes#630.
* test: rename NewFoo in Foo
* test: rename NewFoo in Foo
* fix: improve branch flow to reduce indentation
