There's a lot of reasons why I don't recommend that approach, but I think it's best explained by the following now classic stack overflow post and answer
http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags Basically this applies in your case because recognizing if a sequence of characters is in a comment block or not for HTML is likely not expressible using regexes. There may be a way for a very controlled restricted subset of HTML, but it might require some complex regexes. That said, if you're ok with some false positives and dealing with that, a simple regex based solution is the way to go! Cheers, -- Carter Tazio Schonwald On Friday, March 16, 2012 at 7:08 PM, Joseph Bozeman wrote: > My goal is to remove the HTML comments. It probably would be at least as > efficient to use an HTML parser, but I usually strip files by hand, and I > always use regex then. I didn't want to bother importing yet another package, > because if I could just get this line to work, I could get all my stripping > done with three functions, and then I have four that I use to apply a > template to the text once it's bare. > > On Fri, Mar 16, 2012 at 5:41 PM, Carter Tazio Schonwald > <carter.schonw...@gmail.com (mailto:carter.schonw...@gmail.com)> wrote: > > have you considered using one of the many amazing HTML parsers on hackage? > > > > If the goal is to just get the HTML comments, that might be a much more > > effective use of your time > > > > -- > > Carter Tazio Schonwald > > > > > > On Friday, March 16, 2012 at 4:55 PM, Joseph Bozeman wrote: > > > > > > > > > Hey everyone, I'm hoping someone can point me in the right direction. > > > > > > The regex-pcre package exports (=~) and (=~~) as two useful infix > > > functions. They're great! The only problem is, they are a positive match > > > for a regex. I have a file that contains HTML comments (it was generated > > > in Word) and I really just want the barest text. I already have a > > > function that strips out all the tags, and I have a function that finds > > > all the links and sticks those in another file for later perusal. > > > > > > What I'd like is advice on how to implement the (!~) and (!~~) operators. > > > They should have the same types as (=~) and (=~~). I'm stuck, though. > > > Here's the source for both of those functions: they depend on > > > Text.Rege.PCRE package. > > > > > > (=~) :: (RegexMaker > > > (http://hackage.haskell.org/packages/archive/regex-base/0.93.2/doc/html/Text-Regex-Base-RegexLike.html#t:RegexMaker) > > > Regex > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:Regex) > > > CompOption > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:CompOption) > > > ExecOption > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:ExecOption) > > > source, RegexContext > > > (http://hackage.haskell.org/packages/archive/regex-base/0.93.2/doc/html/Text-Regex-Base-RegexLike.html#t:RegexContext) > > > Regex > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:Regex) > > > source1 target) => source1 -> source -> target > > > (=~) x r = let q :: Regex q = makeRegex r in match q x > > > > > > (=~~) :: (RegexMaker > > > (http://hackage.haskell.org/packages/archive/regex-base/0.93.2/doc/html/Text-Regex-Base-RegexLike.html#t:RegexMaker) > > > Regex > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:Regex) > > > CompOption > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:CompOption) > > > ExecOption > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:ExecOption) > > > source, RegexContext > > > (http://hackage.haskell.org/packages/archive/regex-base/0.93.2/doc/html/Text-Regex-Base-RegexLike.html#t:RegexContext) > > > Regex > > > (http://hackage.haskell.org/packages/archive/regex-pcre/0.94.2/doc/html/Text-Regex-PCRE-Wrap.html#t:Regex) > > > source1 target, Monad > > > (http://hackage.haskell.org/packages/archive/base/4.5.0.0/doc/html/Control-Monad.html#t:Monad) > > > m) => source1 -> source -> m target > > > (=~~) x r = do (q :: Regex) <- makeRegexM r matchM q x > > > What I figured I could do was find a function that was the inverse of > > > "match" and "matchM", but I can't find any in the docs. I really hope I > > > don't have to implement that, too. I'm still new at this, and that seems > > > like it would be over my head. > > > > > > > > > > > > _______________________________________________ > > > Haskell-Cafe mailing list > > > Haskell-Cafe@haskell.org (mailto:Haskell-Cafe@haskell.org) > > > http://www.haskell.org/mailman/listinfo/haskell-cafe > > > > > > > > > > > > > >
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