Commit b5f00004 authored by lewie's avatar lewie
Browse files

[project @ 2001-04-23 19:34:57 by lewie]

Fix for infix decl w/ infix data constructor.
GHC was rejecting this:

    infix 2 |-
    ps  |-  q:qs = undefined

It parses the def as ((ps |- q) : qs), and doesn't have the fixity info
around at the point where it decides what is being defined.  Lacking
anything else to go on, it decides that `:' is being defined.

Fortunately, we don't really need fixity info to parse this correctly,
as a data constructor is always the wrong choice ;-)  The fix is to
dive into the left-hand-side until we find a non-data constructor.

This is naive - consider the case where `|-' has a high precedence.
Fortunately, someone clever put in a static check later on, presumably
at the point where we have all the fixity info, that rejects the definition
as bogus.  Yeah!
parent 23c27aa2
......@@ -271,6 +271,11 @@ checkValSig other ty loc = parseError "Type signature given for an expressio
isFunLhs :: RdrNameHsExpr -> [RdrNameHsExpr] -> Maybe (RdrName, Bool, [RdrNameHsExpr])
isFunLhs (OpApp l (HsVar op) fix r) es | not (isRdrDataCon op)
= Just (op, True, (l:r:es))
| otherwise
= case isFunLhs l es of
Just (op', True, j : k : es') ->
Just (op', True, j : OpApp k (HsVar op) fix r : es')
Nothing -> Nothing
isFunLhs (HsVar f) es | not (isRdrDataCon f)
= Just (f,False,es)
isFunLhs (HsApp f e) es = isFunLhs f (e:es)
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