Comments are started with "--" followed by a character that is not a symbol character. If it is followed by a symbol character (e.g. "*") then the "--" plus the symbol (e.g. "--*") parses as an operator rather than a comment. "p" is not a symbol, so the "--" starts a comment.
For a precise description of Haskell syntax, see the Haskell98 Report[1]. It's quite readable, at least in comparison to other "precise" documents I've attempted to read. Hope that helps. Alex On Wed, Sep 30, 2009 at 7:48 PM, Hong Yang <hyang...@gmail.com> wrote: > Nowhere any Haskell book mentioned "line comments start with "-- ", not just > "--"." It is just people usually put "-- " ahead of comments. > > I can successfully compile "--print bla bla bla." > On Wed, Sep 30, 2009 at 7:36 PM, Sebastian Sylvan > <sebastian.syl...@gmail.com> wrote: >> >> >> On Thu, Oct 1, 2009 at 12:52 AM, Hong Yang <hyang...@gmail.com> wrote: >>> >>> Hi, >>> >>> I got an error if one of lines reads "--++ bla bla bla" where I tried to >>> comment, but "-- ++ bla bla bla" (notice the space after "--") is OK. >>> >>> Do you think this revealed a tiny bug in the GHC compiler (I am using >>> Windows Haskell Platform 2009.2.0.2)? >> >> Line comments start with "-- ", not just "--". >> -- >> Sebastian Sylvan > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe