Re: [Haskell-cafe] ByteString in patterns

10 Mar 2009


      manlio_perillo:
...
Hi.
Using normal String type I can define a pattern like:
...
let foo "baz" = 777
foo "baz"
777
But if I want to use ByteString, what should I do?
This seems impossible, since ByteString data constructor is not available.
-XOverloadedStrings

e.g.

    {-# LANGUAGE OverloadedStrings #-}

    import qualified Data.ByteString.Char8 as C

    isMatch :: C.ByteString -> Bool
    isMatch "match" = True
    isMatch _       = False

    main = print . map isMatch . C.lines =<< C.getContents

Re: [Haskell-cafe] ByteString in patterns

Don Stewart