elm#47 Added parser alternatives for some regex to examples

examples/Regex.elm

@@ -0,0 +1,168 @@
+module Regex exposing (main)
+
+import Char
+import Html exposing (Html, text)
+import List
+import Parser exposing ((|.), (|=), Parser, Step(..), chompIf, chompWhile, end, getChompedString, loop, oneOf, run, succeed, symbol)
+
+
+
+-- MAIN
+
+
+main : Html msg
+main =
+    let
+        runList parseList =
+            case parseList of
+                ( parser, inputStr ) :: xs ->
+                    (Debug.toString <| run parser inputStr) ++ " " ++ runList xs
+
+                _ ->
+                    ""
+    in
+    text <|
+        runList
+            [ ( upperOrDigitExactly4, "AB12" )
+            , ( imageFile, "hello-17.jpeg" )
+            , ( email, "[email protected]" )
+            ]
+            ++ (Debug.toString <| run betweenFishhooks "<trout> What is between the <tuna> fishhooks <salmon>?")
+
+
+
+-- PARSERS
+
+
+chompXCharsIf : Int -> (Char -> Bool) -> Parser ()
+chompXCharsIf x f =
+    if x == 0 then
+        end
+
+    else
+        chompIf f |. chompXCharsIf (x - 1) f
+
+
+oneOfList : List String -> Parser ()
+oneOfList strList =
+    let
+        symbolParsers =
+            List.map symbol strList
+    in
+    oneOf symbolParsers
+
+
+{-| Parser for [A-Z0-9]{4}
+-}
+upperOrDigitExactly4 : Parser String
+upperOrDigitExactly4 =
+    let
+        upperOrDigit =
+            \c -> Char.isUpper c || Char.isDigit c
+    in
+    getChompedString <|
+        succeed identity
+            |. chompXCharsIf 4 upperOrDigit
+            |. end
+
+
+{-| Taken from <https://github.com/hecrj/html-parser/blob/master/src/Html/Parser.elm>
+-}
+chompOneOrMore : (Char -> Bool) -> Parser ()
+chompOneOrMore fn =
+    Parser.chompIf fn
+        |. Parser.chompWhile fn
+
+
+{-| <https://github.com/kmarekspartz/char-extra/blob/1.0.0/src/Char/Extra.elm>
+-}
+isWhitespace : Char -> Bool
+isWhitespace char =
+    List.member char <| String.toList " \t\u{000D}\n"
+
+
+{-| Parser for [^\\s]+.(jpg|png|gif|bmp)$
+-}
+imageFile : Parser String
+imageFile =
+    let
+        nameChars =
+            \c -> (not <| isWhitespace c) && (c /= '.')
+
+        imageExtensions =
+            [ ".jpg", ".jpeg", ".png", ".gif", ".bmp" ]
+    in
+    getChompedString <|
+        succeed identity
+            |. chompOneOrMore nameChars
+            |. oneOfList imageExtensions
+            |. end
+
+
+repeat : Parser () -> Parser ()
+repeat repeatableParser =
+    let
+        repeatHelp : () -> Parser (Step () ())
+        repeatHelp _ =
+            oneOf
+                [ succeed (\_ -> Loop ())
+                    |= repeatableParser
+                , succeed ()
+                    |> Parser.map (\_ -> Done ())
+                ]
+    in
+    loop () repeatHelp
+
+
+{-| Parser for mail address
+^[a-zA-Z0-9.!#$%&’\*+/=?^\_\`{|}~-]+@[a-zA-Z0-9-]+(.[a-zA-Z0-9-]+)\*$
+-}
+email : Parser String
+email =
+    let
+        validCharsBeforeAt =
+            [ '.', '!', '#', '$', '%', '&', '’', '*', '+', '/', '=', '?', '^', '_', '`', '{', '}', '~', '-' ]
+
+        isValidCharBeforeAt c =
+            Char.isAlphaNum c || List.member c validCharsBeforeAt
+
+        isValidCharAfterAt c =
+            Char.isAlphaNum c || c == '-'
+
+        domain =
+            chompIf (\c -> c == '.') |. chompOneOrMore isValidCharAfterAt
+    in
+    getChompedString <|
+        succeed identity
+            |. chompOneOrMore isValidCharBeforeAt
+            |. chompIf (\c -> c == '@')
+            |. chompOneOrMore isValidCharAfterAt
+            |. repeat domain
+            |. end
+
+
+{-| Extract all text between <fishooks>
+<([^>]\*)>
+-}
+betweenFishhooks : Parser (List String)
+betweenFishhooks =
+    loop [] fishhooksHelp
+
+
+fishhooksHelp : List String -> Parser (Step (List String) (List String))
+fishhooksHelp revStrs =
+    let
+        insideFishhooks : Parser String
+        insideFishhooks =
+            getChompedString <| succeed () |. chompWhile (\c -> c /= '>')
+    in
+    oneOf
+        [ succeed (\str -> Loop (str :: revStrs))
+            |. chompWhile (\c -> c /= '<')
+            |. chompIf (\c -> c == '<')
+            |= insideFishhooks
+            |. chompIf (\c -> c == '>')
+            |. chompWhile (\c -> c /= '<')
+        , succeed ()
+            |> Parser.map (\_ -> Done (List.reverse revStrs))
+        ]