Re: [Haskell-cafe] Searching of several substrings (with Data.Text ?)

5 Jul 2011

      Am 05.07.2011 21:29, schrieb Eric Rasmussen:
...
I've been looking into building parsers at runtime (from a config
file), and in my case it's beneficial to fit them into the context of
a larger parser with Attoparsec.Text. This code is untested for
practical use so I doubt you'll see comparable performance to the
aforementioned regex packages, but it could be worth exploring if you
need to mix and match parsers or if the definitions can change
arbitrarily at runtime.
import qualified Data.Text as T
import Data.Attoparsec.Text
import Control.Applicative ((<|>))
parseLigature x = string (T.pack x)
charToText = do c<- anyChar
                 return (T.singleton c)
buildChain [x]    = parseLigature x
buildChain (x:xs) = try (parseLigature x)<|>  buildChain xs
-- ordering matters here, so "ffi" comes before "ff" or "fi"
ligatures = buildChain ["ffi", "th", "ff", "fi", "fl"]
myParser = many (try ligatures<|>  charToText)
-- at ghci prompt: parseOnly myParser (T.pack "the fluffiest bunny")
-- Right ["th","e"," ","fl","u","ffi","e","s","t"," ","b","u","n","n","y"]
Of course parsec! I should have thought of this.
icu seems to be the best solution (I already considered it for parsing 
character references), but it is not so easy to install on windows. So I 
wait until cabal does this or it is integrated into the haskell platform.

Thank you all for your help (especially the attoparsec example)
...
On Tue, Jul 5, 2011 at 12:09 PM, Bryan O'Sullivan  wrote:
...
On Tue, Jul 5, 2011 at 11:01 AM, Tillmann Vogt
  wrote:
...
I looked at Data.Text
http://hackage.haskell.org/packages/archive/text/0.5/doc/html/Data-Text.html
and
http://hackage.haskell.org/packages/archive/stringsearch/0.3.3/doc/html/Data...
but they don't have a function that can search several substrings in one
run.
Here's what you want:
http://hackage.haskell.org/packages/archive/text-icu/0.6.3.4/doc/html/Data-T...

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