[project @ 2002-04-11 12:03:29 by simonpj]
------------------- Mainly derived Read ------------------- This commit is a tangle of several things that somehow got wound up together, I'm afraid. The main course ~~~~~~~~~~~~~~~ Replace the derived-Read machinery with Koen's cunning new parser combinator library. The result should be * much smaller code sizes from derived Read * faster execution of derived Read WARNING: I have not thoroughly tested this stuff; I'd be glad if you did! All the hard work is done, but there may be a few nits. The Read class gets two new methods, not exposed in the H98 inteface of course: class Read a where readsPrec :: Int -> ReadS a readList :: ReadS [a] readPrec :: ReadPrec a -- NEW readListPrec :: ReadPrec [a] -- NEW There are the following new libraries: Text.ParserCombinators.ReadP Koens combinator parser Text.ParserCombinators.ReadPrec Ditto, but with precedences Text.Read.Lex An emasculated lexical analyser that provides the functionality of H98 'lex' TcGenDeriv is changed to generate code that uses the new libraries. The built-in instances of Read (List, Maybe, tuples, etc) use the new libraries. Other stuff ~~~~~~~~~~~ 1. Some fixes the the plumbing of external-core generation. Sigbjorn did most of the work earlier, but this commit completes the renaming and typechecking plumbing. 2. Runtime error-generation functions, such as GHC.Err.recSelErr, GHC.Err.recUpdErr, etc, now take an Addr#, pointing to a UTF8-encoded C string, instead of a Haskell string. This makes the *calls* to these functions easier to generate, and smaller too, which is a good thing. In particular, it means that MkId.mkRecordSelectorId doesn't need to be passed "unpackCStringId", which was GRUESOME; and that in turn means that tcTypeAndClassDecls doesn't need to be passed unf_env, which is a very worthwhile cleanup. Win/win situation. 3. GHC now faithfully translates do-notation using ">>" for statements with no binding, just as the report says. While I was there I tidied up HsDo to take a list of Ids instead of 3 (but now 4) separate Ids. Saves a bit of code here and there. Also introduced Inst.newMethodFromName to package a common idiom.