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Re: [GHC] #474: Debug.Trace.trace should work on Show: msg#00053

lang.haskell.glasgow.bugs

Subject: Re: [GHC] #474: Debug.Trace.trace should work on Show

#474: Debug.Trace.trace should work on Show
------------------------------+---------------------------------------------
Reporter: jch | Owner: nobody
Type: feature request | Status: reopened
Priority: lowest | Milestone: 6.4.2
Component: libraries/base | Version: None
Severity: minor | Resolution:
Keywords: | Os: Unknown
Difficulty: Unknown | Architecture: Unknown
------------------------------+---------------------------------------------
Old description:

> {{{
> Debug.Trace.trace has type
>
> trace :: String -> a -> a
>
> which forces me to insert calls to show. Could it be
> generalised to
>
> trace :: Show a => a -> b -> b
>
> Thanks,
>
> Juliusz Chroboczek
>
> }}}

New description:

{{{
Debug.Trace.trace has type

trace :: String -> a -> a

which forces me to insert calls to show. Could it be
generalised to

trace :: Show a => a -> b -> b

Thanks,

Juliusz Chroboczek

}}}

Comment (by simonmar):

This is similar to the difference between {{{print}}} and {{{putStr}}},
that is, there are good reasons to have both.

I've no objection to adding
{{{
traceShow :: Show a => a -> b -> b
traceShow = trace . show
}}}
but that doesn't seem to save a whole lot of typing. Perhaps a different
name?

--
Ticket URL: <http://cvs.haskell.org/trac/ghc/ticket/474>
GHC <http://www.haskell.org/ghc/>
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