Motivation is that implicit (non-overriden) list features must unify
with list of any length. Consider an example:
`classifier(cls: node-ptr/A/) = classifier(cls: node-ptr/A/ param: [B,C])`
With previous approach it would fail, which seems counter-intuitive to me.
So, if empty list (e.g. of type parameters) is meant, then it must be
specified explicitly.
There's one thing to remember, though: such wildcard list features
won't match with MetaLogicalArrays in rule heads.
(e.g. see dpromote_* rules and consider what happens when
a classifier with unbound `parameter` feature comes in)
Introduce common 'parameterized(child typeParams)' term
to allow unifying processing of GenericDeclarations.
Collect type variables from enclosing GenericDeclaration.
Will be needed to simplify instantiation of nested generic decls
(e.g. generic method inside generic class) using `genDecl`
machinery instead of TypeVarSubstitution.
As closures typesystem depends on collections due to sequence type,
so collections typesystem depends on closures due to function type.
E.g. consider typechecking of SequenceCreator.
Also fuse two bl rules for return statement and last expr.
Output feedback on return stmt, not returned expr,
because it also handles case of erroneous void return
Modified TYPECHECK query to include "checkingScope" query parameter:
it is a root node for which program is generated (for local typechecking it's local node).
Rules additionally match on a constraint `checkDecls(node<>)` bearing this node,
so while rules will be generated for all scopes, only those in applicable scopes will run.
Also split rule for EnumConstantDeclaration on declration checking and just typing rule.
Now primitive types in conversion relation are handled before processing of free inference vars.
So primitive types first get boxed and only then these terms can be unified with inference vars.
To avoid confusion, a rule defines "target ref", which is supposed
to indicate the source code location for possible errors.
The origin node is to be referred as "origin" as before.
Temporarily rename OriginSpec's alias to "target" to reflect change
in semantics.
Grigorii Kirgizov