[issue] show to_proc bug

[ptarjan]

I don't know how to fix this one. I tried but the handling of :to_proc wasn't making sense to me. It seems to be trying to resolve bar based on the scoping immediately instead of later when it is called, and the shape of the call seemed to not know about how it was being called.

The assignment to a and the assignment to b should be typechecked the same way. a succeed and b fails with

  1) Error:
TestTypecheck#test_to_proc:
RDL::Typecheck::StaticTypeError:
/Users/pt/stripe/rdl/test/test_typecheck.rb:1666:28: error: block argument has type `() -> Integer' but expecting type `(TestTypecheck::ToProc) -> u'
/Users/pt/stripe/rdl/test/test_typecheck.rb:1666:         b = [self.new].map(&:bar)
/Users/pt/stripe/rdl/test/test_typecheck.rb:1666:                            ^~~~~
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:158:in `error'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1441:in `tc_block'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1298:in `block (2 levels) in tc_send_one_recv'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1294:in `each'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1294:in `block in tc_send_one_recv'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1291:in `each'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1291:in `tc_send_one_recv'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1214:in `block in tc_send'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1213:in `each'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:1213:in `tc_send'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:678:in `block in tc'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:140:in `scope_merge'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:655:in `tc'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:476:in `tc'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:913:in `block in tc'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:913:in `each'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:913:in `tc'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:247:in `block in typecheck'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:226:in `each'
    /Users/pt/stripe/rdl/lib/rdl/typecheck.rb:226:in `typecheck'
    /Users/pt/stripe/rdl/lib/rdl/wrap.rb:57:in `block in foo'
    /Users/pt/stripe/rdl/lib/rdl/switch.rb:13:in `off'
    /Users/pt/stripe/rdl/lib/rdl/wrap.rb:48:in `foo'
    /Users/pt/stripe/rdl/test/test_typecheck.rb:1674:in `test_to_proc'