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
* 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
mpl
Marc Vertes