[Haskell-beginners] wrapping text in a multiline string

[Arlen Cuss]

I'd be more inclined to look at a solution involving manipulating the HTML structure, rather than trying a regexp-based approach, which will probably end up disappointing. (See this: http://stackoverflow.com/a/1732454/499609)

I hope another Haskeller can speak to a library that would be good for this kind of purpose.

To suit what you're doing now, though; if you change .*? to [\s\S]*?, it should work on multiline strings. If you can work out how to pass the 's' modifier to Text.Regexp.PCRE, that should also do it.

—Arlen  


On Wednesday, 6 June 2012 at 3:05 PM, Rico Moorman wrote:

> Hello,
>  
> I have a given piece of multiline HTML (which is generated using pandoc btw.) and I am trying to wrap certain elements (tags with a given class) with a <div>.  
>  
> I already took a look at the Text.Regex.PCRE module which seemed a reasonable choice because I am already familiar with similar regex implementations in other languages.
>  
> I came up with the following function which takes a regex and replaces all matches within the given string using the provided function (which I would use to wrap the element)
>  
> import Text.Regex.PCRE ((=~~))
>  
> -- Replaces the whole match for the given regex using the given function
> regexReplace :: String -> (String -> String) -> String -> String
> regexReplace regex replace text = go text
> where
> go text = case text =~~ regex of
> Just (before, match, after) ->
> before ++ replace match ++ go after
> _ -> text
>  
> The problem with this function is, that it will not work on multiline strings. I would like to call it like this:
>  
> newBody = regexReplace "<table class=\"sourceCode\".*?table>" wrap body  
> wrap x = "<div class=\"sourceCodeWrap\">" ++ x ++ "</div>"
>  
> Is there any way to easily pass some kind of multiline modifier to the regex in question?  
>  
> Or is this approach completely off and would something else be more appropriate/haskelly for the problem at hand?
>  
> Thank you very much in advance.  
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