Just another update

Task/URL-decoding/00DESCRIPTION

@@ -1,4 +1,5 @@
-This task (the reverse of [[URL encoding]]) is to provide a function or mechanism to convert an URL-encoded string into its original unencoded form.
+This task (the reverse of [[URL encoding]]) is to provide a function
+or mechanism to convert an URL-encoded string into its original unencoded form.
 
 '''Example'''
 

Task/URL-decoding/Ada/url-decoding-2.ada

@@ -0,0 +1,3 @@
+package URL is
+   function Decode (URL : in String) return String;
+end URL;

Task/URL-decoding/Ada/url-decoding-3.ada

@@ -0,0 +1,28 @@
+package body URL is
+   function Decode (URL : in String) return String is
+      Buffer   : String (1 .. URL'Length);
+      Filled   : Natural := 0;
+      Position : Positive := URL'First;
+   begin
+      while Position in URL'Range loop
+         Filled := Filled + 1;
+
+        case URL (Position) is
+            when '+' =>
+               Buffer (Filled) := ' ';
+               Position := Position + 1;
+            when '%' =>
+               Buffer (Filled) :=
+                 Character'Val
+                   (Natural'Value
+                      ("16#" & URL (Position + 1 .. Position + 2) & "#"));
+               Position := Position + 3;
+            when others =>
+               Buffer (Filled) := URL (Position);
+               Position := Position + 1;
+         end case;
+      end loop;
+
+      return Buffer (1 .. Filled);
+   end Decode;
+end URL;

Task/URL-decoding/Ada/url-decoding-4.ada

@@ -0,0 +1,16 @@
+with Ada.Command_Line,
+     Ada.Text_IO;
+
+with URL;
+
+procedure Test_URL_Decode is
+   use Ada.Command_Line, Ada.Text_IO;
+begin
+   if Argument_Count = 0 then
+      Put_Line (URL.Decode ("http%3A%2F%2Ffoo%20bar%2F"));
+   else
+      for I in 1 .. Argument_Count loop
+         Put_Line (URL.Decode (Argument (I)));
+      end loop;
+   end if;
+end Test_URL_Decode;

Task/URL-decoding/Haskell/url-decoding.hs

@@ -0,0 +1,15 @@
+import qualified Data.Char as Char
+
+urlDecode :: String -> Maybe String
+urlDecode [] = Just []
+urlDecode ('%':xs) =
+  case xs of
+    (a:b:xss) ->
+      urlDecode xss
+      >>= return . ((Char.chr . read $ "0x" ++ [a,b]) :)
+    _ -> Nothing
+urlDecode ('+':xs) = urlDecode xs >>= return . (' ' :)
+urlDecode (x:xs) = urlDecode xs >>= return . (x :)
+
+main :: IO ()
+main = putStrLn . maybe "Bad decode" id $ urlDecode "http%3A%2F%2Ffoo%20bar%2F"

Task/URL-decoding/Maple/url-decoding.maple

@@ -0,0 +1 @@
+StringTools:-Decode("http%3A%2F%2Ffoo%20bar%2F", encoding=percent);

Task/URL-decoding/NewLISP/url-decoding.newlisp

@@ -0,0 +1,7 @@
+;; universal decoder, works for ASCII and UTF-8
+;; (source http://www.newlisp.org/index.cgi?page=Code_Snippets)
+(define (url-decode url (opt nil))
+  (if opt (replace "+" url " "))
+  (replace "%([0-9a-f][0-9a-f])" url (pack "b" (int $1 0 16)) 1))
+
+(url-decode "http%3A%2F%2Ffoo%20bar%2F")

Task/URL-decoding/R/url-decoding.r

@@ -0,0 +1 @@
+URLdecode("http%3A%2F%2Ffoo%20bar%2F")

Task/URL-decoding/Scala/url-decoding.scala

@@ -1,4 +1,16 @@
-import java.net._
-val encoded="http%3A%2F%2Ffoo%20bar%2F"
-val decoded=URLDecoder.decode(encoded, "UTF-8")
-println(decoded)   // -> http://foo bar/
+import java.net.{URLDecoder, URLEncoder}
+import scala.compat.Platform.currentTime
+
+object UrlCoded extends App {
+  val original = """http://foo bar/"""
+  val encoded: String = URLEncoder.encode(original, "UTF-8")
+
+  assert(encoded == "http%3A%2F%2Ffoo+bar%2F", s"Original: $original not properly encoded: $encoded")
+
+  val percentEncoding = encoded.replace("+", "%20")
+  assert(percentEncoding == "http%3A%2F%2Ffoo%20bar%2F", s"Original: $original not properly percent-encoded: $percentEncoding")
+
+  assert(URLDecoder.decode(encoded, "UTF-8") == URLDecoder.decode(percentEncoding, "UTF-8"))
+
+  println(s"Successfully completed without errors. [total ${currentTime - executionStart} ms]")
+}

Task/URL-decoding/VBScript/url-decoding.vb

@@ -0,0 +1,14 @@
+Function UrlDecode(s)
+	For i = 1 To Len(s)
+		If Mid(s,i,1) = "%" Then
+			UrlDecode = UrlDecode & Chr("&H" & Mid(s,i+1,2))
+			i = i + 2
+		Else
+			UrlDecode = UrlDecode & Mid(s,i,1)
+		End If
+	Next
+End Function
+
+url = "http%3A%2F%2Ffoo%20bar%2F"
+WScript.Echo "Encoded URL: " & url & vbCrLf &_
+	"Decoded URL: " & UrlDecode(url)