remove numbers from a string haskell

> import Data.List.Split
> split (dropDelims . dropBlanks $ oneOf " 0123456789") "I go 25abc tomorrow 100!"
["I","go","abc","tomorrow","!"]

with words a two step approach will work

> words $ map (\x -> if x `elem` ['a'..'z']++['A'..'Z'] then x else ' ') "I go 25abc tomorrow 100!"
["I","go","abc","tomorrow"]

here I changed the definition of filter to only alpha chars, if not matches your needs you can reverse the if condition by defining the filtered out chars.

By importing Data.Char(isAlpha) you can change

x `elem` ['a'..'z']++['A'..'Z'] 

to isAlpha x

You could define a recursive function like this:

import Data.Char

split :: String -> [String]
split [] = []
split s =
  let -- Remove non alphabetic characters from front of list
      s' = dropWhile (not . isAlpha) s
      -- Split the list at the point where the first non-alphabetic
      -- character appears
      (xs,ys) = span isAlpha s'
      -- Recursively call split on the second list, while prepending 
      -- the first list.
  in  xs:(split ys)

Here is what happens with your test string through the recursive calls:

s  = "I go 25abc tomorrow 100!"
s' = "I go 25abc tomorrow 100!"
xs = "I"
ys = " go 25abc tomorrow 100!"

s  = " go 25abc tomorrow 100!"
s' = "go 25abc tomorrow 100!"
xs = "go"
ys = " 25abc tomorrow 100!"

s  = " 25abc tomorrow 100!"
s' = "abc tomorrow 100!"
xs = "abc"
ys = " tomorrow 100!"

s  = " tomorrow 100!"
s' = "tomorrow 100!"
xs = "tomorrow"
ys = " 100!"

s  = " 100!"
s' = ""
xs = ""
ys = ""

Note that this will split the word "abc4def" into ["abc", "def"].

Below line of code will split the string whenever it finds number

String[] strArr= str.split("[0-9]");

The following should do it.

splitWithoutNumbers :: String -> [String]
splitWithoutNumbers = map removeNumbers.words
                      where 
                      removeNumbers ""     = ""
                      removeNumbers (s:ss) | isNumber s = removeNumbers ss
                                           | otherwise  = s : removeNumbers ss

*Main> splitWithoutNumbers "I go 25abc tomorrow 100!"
["I","go","abc","tomorrow","!"]

import Data.Char
import Control.Monad
remove = words . filter (liftM2 (||) isAlpha isSpace)