[ ghc-Bugs-1191681 ] parse error on input

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Bugs item #1191681, was opened at 2005-04-28 15:07
Message generated for change (Comment added) made by wthaller
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Category: Compiler
Group: 6.4
>Status: Closed
>Resolution: Invalid
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: parse error on input

Initial Comment:
On GHC 6.4 on Mac OS X 10.3.9, the one-line file (t.hs) with 
exactly the following contents

module A where m=(\n->n+)

incorrectly produces a syntax error:

~/working/bugs% ghc -c t.hs

t.hs:1:25: parse error on input `)'

The + can be replaced with - or * or > and will still produce the 
same error.

AND the following one-line file (t1.hs)

module A where m=\n->n

produces the error

t1.hs:1:19: parse error on input `->'

BUT, adding a space after the = produces no error (t2.hs):

module A where m= \n->n

(Maybe =\ is parsed as one token.  But that doesn't explain t.hs, 
to which a space can be added and the problem doesn't go 
away.)

--
Robin Bate Boerop
robin at bateboerop.name

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>Comment By: Wolfgang Thaller (wthaller)
Date: 2005-04-28 18:05

Message:
Logged In: YES 
user_id=566359

\n->n+ is not correct Haskell. If you want to write an operator section, you 
need parantheses there: \n->(n+)

As for the second case, yes, =\ is one token.


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