On 09 December 2005 05:47, Taral wrote:
On 12/8/05, Taral <taralx@gmail.com> wrote:
or b) comment, because the maximal munch rule says so (it matches the newline):
comment -> dashes [any<symbol> {any}] newline varsym -> (symbol {symbol | :})<reservedop | dashes>
Aha. Maximal munch only applies to non-whitespace, so Hugs is right. Yay.
This looks like a mistake in the syntax. I think GHC is following the letter of the spec, but I also think that the intended behaviour was to admit --: as a varsym, i.e. Hugs' behaviour. The syntax allows --: to be a comment, because the class of characters "symbol" does not include :. In contrast, the syntax does *not* admit varsyms beginning with '--' as comments. I'm not aware of maximal munch being applied only to non-whitespace; does it say so anywhere in the report? Cheers, Simon