Error in variable pattern matching

[PhucVH888]

In the following example, the second clause of pattern matching does not bind to variable z.

class Main
  def main() : void {
    let f = \(a:int) ->
      match a with
        0 => print "match"
        z => print "does not match"
    in ()
}

It raises the error when I compile the above snippet.

phuc:workspace vo$ encorec test.enc
Importing module String from /Users/vo/code/encore/bundles/standard/String.enc
test_src/Main.encore.c:108:41: error: use of undeclared identifier '_enc__closure_z'
  (*_enc__env_closure0)._enc__field_z = _enc__closure_z;
                                        ^
1 error generated.
 *** Compilation failed with exit code 1 ***

[EliasC]

The problem is that the variables in the pattern of a match expression is mistaken for free variables, meaning that the closure thinks it should be part of the environment.

Fix:

Add the following as the second to last case of freeVariables' in src/AST/Util.hs:

      freeVariables' bound Match {arg, clauses} =
          freeVariables' bound arg ++ clausesFreeVars
          where
            clausesFreeVars = concatMap clauseFreeVars clauses
            clauseFreeVars MatchClause{mcpattern, mcguard, mchandler} =
                let boundInPattern = map fst $ freeVariables' [] mcpattern
                    bound' = boundInPattern ++ bound
                    freeInGuard = freeVariables' bound' mcguard
                    freeInHandler = freeVariables' bound' mchandler
                in
                  freeInGuard ++ freeInHandler

@glundi: Feel free to double check my work (and submit a PR) :)

[TheGrandmother]

Has this issue been fixed yet ?

[kikofernandez]

this issue has been fixed!