[Haskell-cafe] Re: Editors for Haskell

Malcolm Wallace Malcolm.Wallace at cs.york.ac.uk
Fri Jun 2 05:55:15 EDT 2006

"Brian Hulley" <brianh at metamilk.com> wrote:

> Thanks for pointing this out. Although there is still a problem with
> the  fact that var, qvar, qcon etc is in the context free syntax
> instead of the  lexical syntax so you could write:
>         2 `    plus      ` 4
>         (    Prelude.+
>                {- a comment -} ) 5 6

You appear to be right.  However, I don't think I have ever seen a piece
of code that actually used the first form.  People seem to naturally
place the backticks right next to the variable name.  Should we consider
the fact that whitespace and comments are permitted between backticks to
be a bug in the Report?  It certainly feels like it should be a lexical

On the other hand, the second form looks a lot like just bracketting an
ordinary expression, and whitespace and comments can frequently be seen
in such a position.  If we disallow whitespace in the backtick case, it
would feel wrong to permit it in the parenthesised "dual".

Does anyone from the original language committee have any memory of why
these choices were taken?


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