[cvs-nhc98] patch applied (hat): When lexing, use a perfect hash function to recognise language

Tue Jan 22 03:02:49 PST 2002 malcolm * When lexing, use a perfect hash function to recognise language keywords, rather than the previous chained conditionals. This makes the compiler approx 2% faster when built with nhc98 - there is no discernible effect on performance when built with ghc. Nevertheless I'm committing the change, because on a full build of nhc98 with itself the 2% speedup totals to about 10 minutes saving. M ./src/compiler98/LexLow.hs -73 +130