Amanda Clare
Is it possible that the instance of "read" for Doubles when using hat can't handle negative numbers? I get "Error: Prelude.read: no parse" whenever I have a negative number to read. My program works fine without hat.
Indeed. This fault is because we took the code directly from the (incorrect) Haskell Report! Here's a patch. Regards, Malcolm Index: src/hat/lib/PreludeBasic.hs =================================================================== RCS file: /usr/src/master/nhc/src/hat/lib/PreludeBasic.hs,v retrieving revision 1.12 diff -u -r1.12 src/hat/lib/PreludeBasic.hs --- src/hat/lib/PreludeBasic.hs 2002/05/03 15:22:36 1.12 +++ src/hat/lib/PreludeBasic.hs 2002/07/17 16:40:13 @@ -1940,7 +1940,7 @@ instance Read Float where - readsPrec p = readFloat + readsPrec p = readSigned readFloat instance Show Double where @@ -1948,7 +1948,7 @@ instance Read Double where - readsPrec p = readFloat + readsPrec p = readSigned readFloat instance Show () where