On 30 August 2005 12:05, Arthur Baars wrote: > Daan is right, I wrote a parser for GHC using Doaitse Swierstra's > parsing combinator library > (http://www.cs.uu.nl/groups/ST/Software/UU_Parsing/index.html). > I needed a drop-in replacement for GHC's Happy parser, to make a > prototype for syntax macros. Syntax Macros allow a programmer to > extend a language with new syntax. Combinator based parsers parsers > can be dynamically extended, making them suitable for implementing > syntax macros. Unfortunately, I never had time to really finish the > syntax macro implementation. > > But I did finish the combinator based parser for GHC. I tested it by > having GHC( with combinator parser) compile itself and all the > libraries. This took about 10% longer than with the original GHC, so > in practice its speed is acceptable.
With all due respect, a 10% increase in compile time isn't acceptable at all! And when you consider that parsing is less than 10% of compile time overall (probably much less), a 10% increase represents at least a factor of 2 in the parser. I'm not criticising the work at all - far from it, just the notion that we would consider adding 10% to GHC's compile times "acceptable". I've recently been struggling to shave a few percent off GHC's compile times, BTW :-) Cheers, Simon _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe