Re: [Haskell-cafe] Parsing floating point numbers

On Sun, 8 Mar 2009, Felipe Lessa wrote:

On Sun, Mar 8, 2009 at 9:34 PM, Bjorn Buckwalter wrote:

...

(For my current needs the formats accepted by "read" are sufficient, but I want reasonable error handling (Maybe or Either) instead of an exception on bad inputs.)

Why not

readM :: (Monad m, Read a) => String -> m a readM str = case [x | (x,"") <- readsPrec 0 str] of [x] -> return x _ -> fail "readM: failed"

Also, I remember seeing this function exported by some module, but I don't remember where.

http://www.haskell.org/pipermail/libraries/2008-February/009202.html http://www.haskell.org/pipermail/haskell-cafe/2008-June/044590.html Although maybeRead was proposed, I cannot find it: http://hackage.haskell.org/packages/archive/base/4.0.0.0/doc/html/Text-Read.... (Btw. I find it really great, that now the 'base' package documentation can be found on Hackage!)