id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
2204,Improve 'patterns not matched' warnings,Deewiant,,"Compiling the following with `-fwarn-incomplete-patterns`:

{{{
module Asdf where

f :: String -> Int
f ""0"" = 0

g :: Int -> Int
g 0 = 0
}}}

Yields:

{{{
asdf.hs:4:0:
    Warning: Pattern match(es) are non-exhaustive
             In the definition of `f':
                 Patterns not matched:
                     []
                     (GHC.Base.C# #x) : _ with #x `notElem` ['0']
                     (GHC.Base.C# '0') : (_ : _)

asdf.hs:7:0:
    Warning: Pattern match(es) are non-exhaustive
             In the definition of `g':
                 Patterns not matched: GHC.Base.I# #x with #x `notElem` [0#]
}}}

Losing the 'GHC.Base' stuff along with the various octothorpes would make the error messages a lot nicer. Ideally it'd be something like `Patterns not matched: x where x `notElem` [0]` for the second case, for instance.",feature request,new,low,_|_,Compiler,6.8.2,,,marcot@…,Unknown/Multiple,Unknown/Multiple,None/Unknown,Unknown,,,,