Re: Greedy matching in prg2lout

[Jeff Kingston]

On Thu, 27 Feb 2003 09:31:52 +0300 (MSK), Darren Bane wrote:
  > 
  > Hi there,
  > 
  > I'm trying to add support for RSL (the RAISE Specification Language - 
  > http://www.iist.unu.edu/raise/) to prg2lout.  This is somewhat different 
  > from the other programming languages supported because symbol mode 
  > should be the default, and there are many more mathematical operators.
  > 
  > One of these is the word 'is', which renders as the equivalence symbol 
  > (i.e. = with an extra line).  I added FixedToken entries for this, and 
  > it rendered perfectly.  However, now _any_ sequence of the characters 
  > i-s is replaced with equivalence, even identifiers like is_empty and 
  > is_full.

I think the way to handle this is to tell prg2lout that "is" is a
keyword, and then in file raisef (equivalent of eiffelf etc.) put
a @Case expression into the command for printing keywords:

    def @PK right x
    {
       x @Case {
          "is" @Yield @Sym equiv
          else @Yield {
             ... what's there now ...
          }
       }
    }

>From memory I don't think prg2lout itself would have the ability
to do this by itself.  There could be something buried in it I
guess, as you say, handling Perl is not easy either.  But the
above seems a lot more straightforward anyway.

Jeff Kingston