[Haskell-cafe] Re: Parsec question (new user): unexpected end of input

[Christian Maeder]

Am 29.09.2010 05:35, schrieb Peter Schmitz:
[...]
> Error parsing file: "...\sampleTaggedContent.txt" (line 4, column 1):
> unexpected end of input
> expecting "<"
> 
> The input was:
[...]
> 
>> -- Parsers:
>> taggedContent = do
>>    optionalWhiteSpace
>>    aTag
>>    many tagOrContent
>>    aTag

"many tagOrContent" will consume all tags, so that no tag for the
following "aTag" will be left.

Cheers Christian

>>    eof
>>    return "Parse complete."
>>
>> tagOrContent = aTag <|> someContent <?> "tagOrContent"
>>
>> aTag = do
>>    tagBegin
>>    xs <- many (noneOf [tagEndChar])
>>    tagEnd
>>    optionalWhiteSpace
>>    return ()
>>
>> someContent = do
>>    manyTill anyChar tagBegin
>>    return ()
>>
>> optionalWhiteSpace = spaces   -- i.e., any of " \v\f\t\r\n"
>> tagBegin = char tagBeginChar
>> tagEnd = char tagEndChar
>>
>> -- Etc:
>> tagBeginChar = '<'
>> tagEndChar = '>'
> 
> --------