Matching of a reified type does not work properly (in interpreter and compile)

[PaulKlint]

Reported by @tvdstorm:

module experiments::Compiler::Examples::Tst

value main(list[value] args) = type(\int(), _) := #int;

gives with the interpreter

rascal>main([])
value: false   <=== should be true

and with the compiler it gives a static error (but should be accepted):

rascal>execute(|rascal:///experiments/Compiler/Examples/Tst.rsc|, [], recompile=true)
...
error("Cannot match an expression of type: reified[int] against a pattern of type reified[value]",|project://rascal/src/org/rascalmpl/library/experiments/Compiler/Examples/Tst.rsc|(76,15,<3,31>,<3,46>))

@mahills can you have a look at this type checker issue?

[mahills]

This appears to be because Type needs to be imported in order to get the various constructors that are used (e.g., \int()) in the matches. If I do that, this works fine.

[jurgenvinju]

The type checker should then complain about the undefined int() constructor in the pattern.

[mahills]

Agreed, given the way the pattern matching code works the type checker tends to "hide" messages that come out of it, since this could lead to a number of spurious messages, but it's sometimes hiding these too well. I'll look at rebalancing this.

[PaulKlint]

We now get a good message: The declaration for constructor or production int is not in scope