[Python-Dev] Parsing vs. lexing.

Alex Martelli aleax@aleax.it
Wed, 21 Aug 2002 22:25:27 +0200


On Wednesday 21 August 2002 09:50 pm, Zack Weinberg wrote:
	...
> You might be interested to know that over in GCC land we're changing
> the C++ front end to use a hand-written recursive descent parser.
> It's not done yet, but we expect it to be easier to maintain, faster,
> and better at generating diagnostics than the existing yacc-based
> parser.

Interesting!  This reminds me of a long-ago interview with Borland's techies
about how they had managed to create Turbo Pascal, which ran well in
a 64K (K, not M-) one-floppy PC, when their competitor, Microsoft Pascal, 
forced one to do a lot of disc-jockeying even with 256K and 2 floppies.

Basically, their take was "we just did everything by the Dragon Book -- except
that the parser is a hand-written recursive descent parser [Aho &c being
adamant defenders of Yacc & the like], which buys us a lot" ...


Alex