I'm all for it. Just need to watch for performance regressions Simon | -----Original Message----- | From: Herbert Valerio Riedel [mailto:hvriedel@gmail.com] | Sent: 21 June 2014 11:10 | To: Simon Peyton Jones | Cc: ghc-devs | Subject: Int-based lexer flag bitmask exhausted | | Hello Simon (et al.), | | While doing #9224[1] as a finger-exercise to extend the lexer to support | base-2 integer literals, I got stuck on the lexer extension map being | represented as an 'Int', which (in GHC) is only guaranteed to hold least | 32bits. | | -- for reasons of efficiency, flags indicating language extensions (eg, | -- -fglasgow-exts or -XParallelArrays) are represented by a bitmap | -- stored in an unboxed Int | | However, as all 32bits are already taken up by language extensions, and | I'd need a 33th bit, I'm wondering how to proceed. Can we replace the | 'Int' by an 'Int64' (or even better a Word64, ideally with a newtype or | at least a type-synonym around it?) which would give us a bit more | headroom while being semantically sound even for 'bitSize Int == 32'? | | [1]: https://ghc.haskell.org/trac/ghc/ticket/9224 | | Cheers, | hvr