[jhc] Re: jhc-0.7.1 and parsec-2.1.0.1

[Chris Eidhof]

Hey everyone,

I'm trying to compile parsec-2.1.0.1 as well, but there's a different  
error. I get an "irrefutable failed for pattern (p:ps)" the following  
snippet of code.

> tidyHeads ::
>     Monad m
>     => E
>     -> [([HsPat],E->E)]  -- [(pats,else -> value)]
>     -> Ce m [(HsPat,[HsPat],E->E)]  -- pulls the head off of each  
> pattern, tidying it up perhaps
> tidyHeads b ps = mapM f ps where
>     f (~(p:ps),fe) = do
>         (p',fe') <- tidyPat p b
>         return (p',ps,fe' . fe)

I'm not sure what this code does, so I don't know what would be a good  
implementation for f ([],fe)... any help would be appreciated.

Thanks,

-chris

On 1 sep 2009, at 20:00, John Meacham wrote:

> On Tue, Sep 01, 2009 at 10:28:48AM +0200, Christian Maeder wrote:
>> John Meacham wrote:
>>> On Fri, Aug 28, 2009 at 02:07:17PM +0200, Christian Maeder wrote:
>>>> Hi,
>>>>
>>>> I've tried to compile (part of) parsec-2.1.0.1 with jhc-0.7.1
>>>>
>>>> and Parsec.Combinator had several problems with do-expression as  
>>>> infix
>>>> arguments, which should be simple to fix for you. I.e.
>>>>
>>>>  do{ p; return ()} <|> return ()
>>>>
>>>> needed explicit parenthesis:
>>>>
>>>>  (do{ p; return ()}) <|> return ()
>>>>
>>>> (also if layout is used instead of curly braces)
>>>
>>> Hmm.. okay. this may be related to
>>> http://repetae.net/computer/jhc/bug/issue-35cc6ddc1a577e163e9830b96f89151f0562c029.html
>>> I'll look into it. thanks for the report!
>>
>> No, it's the infix analysis. The "where"-Problem has to do with your
>> different offside (by one).
>
> Ah. I see what is happening. I am desugaring before re-fixitying the
> source code. Thanks! I see the issue now. I was thinking it was a
> parsing problem.
>
>        John
>
> -- 
> John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/
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