At 08:57 07/04/04 +0100, Simon Peyton-Jones wrote:

...

cpp is readily available everywhere, whereas some new tool would not be.

Hmmm... it was my perception of the falsity of this that led me to raise the issue in the first place. See also [1].

Otherwise, I broadly agree with the points you make.

One good reason for implementing our own preprocessor that nobody has raised yet is that the implementation of cpp we all use (gcc) is not under our control and recently has been changing its semantics in ways that affect us. CPP in gcc 3.4 interprets '\' followed by whitespace at the end of a line as a line continuation; previous versions of cpp didn't do that, and it makes it impossible to use Haskell string gaps in CPP'd Haskell source. I don't trust the GCC guys to keep the -traditional flag around for ever either. I'd settle for just finding a good standalone open source cpp, removing any undesirable features, and shipping it with the compilers. BTW, Hugs copes with CPP directives in the standard libraries by running CPP over the source code before packaging up the distribution: that way CPP isn't required on the target system. Cheers, Simon