examples.hs

import Text.Regex.VerbalExpressions
import Control.Arrow

main :: IO()
main = do
    --create an example of how to test for correctly formed URLs
    let expr = searchGlobal >>>
            startOfLine     >>>
            find "http"     >>>
            possibly "s"    >>>
            find "://"      >>>
            possibly "www"  >>>
            anythingBut " " >>>
            endOfLine
            $ verEx

    -- Use VerEx's test function to find if it matches
    print $ test "http://www.google.com" expr

    --Ouputs the actual expression used: ^(?:http)(?:s)?(?:://)(?:www.)?(?:[^ ]*)$
    print $ expr

    -- Create a test string
    let replaceMe = "Replace bird with a duck"
    -- Create an expression that seeks for word "bird"
    let expr2 = find "bird" $ verEx;
    
    -- Execute the expression
    print $ replace replaceMe "duck" expr2

    -- Shorthand string replace
    print $ replace "We have a red house" "blue" . find "red" $ verEx