Re: [Haskell-beginners] subRegex https? with anchor href tags

On Saturday 12 November 2011, 14:23:30, Shakthi Kannan wrote:

Hi,

--- On Sat, Nov 12, 2011 at 5:44 PM, Daniel Fischer

wrote: | Maybe the backreferences numbering starts at 0?

Not backreferences, but who cares?

| Worth a try.

\--

\0 represents the entire string match:

The entire *match*, that is, the part of the input matched by the regexp. The other entries correspond to parts matched by certain subregexen in the match.

http://cvs.haskell.org/Hugs/pages/libraries/base/Text-Regex.html

May I suggest using the docs at hackage, hugs hasn't had a release since 2006, I don't think the docs are up to date. Unless you're actually using hugs, in which case I suggest switching to ghc. http://hackage.haskell.org/package/regex-compat

Prelude Text.Regex> subRegex (mkRegex "e") "hello" "\\0" "hello"

Heh, I didn't see it immediately either ;) Prelude Text.Regex> subRegex (mkRegex "e") "hello" ">\\0<" "h>e subRegex (mkRegex "https?[^\\s\n\r]+") "The best is http://haskell.org" "there</a>" "The best is http://ha\">there</a>skell.org" Not what you want, character classes don't work that way, Prelude Text.Regex> subRegex (mkRegex "https?[^[:space:]]+") "The best is http://haskell.org\n" "there</a>" "The best is http://haskell.org\">there</a>\n" but that. However, Prelude Text.Regex> subRegex (mkRegex "https?[^[:space:]]+") "The best is http://haskell.org." "there</a>" "The best is http://haskell.org.\">there</a>" please make an effort to not include final punctuation in the href, it's rather annoying how many 404s I get from that.