Add unescape-html sub

.editorconfig

@@ -0,0 +1,10 @@
+[*]
+charset              = utf8
+end_of_line          = lf
+insert_final_newline = true
+indent_style         = space
+indent_size          = 4
+
+[*.json]
+indent_style = space
+indent_size  = 4

META6.json

@@ -13,7 +13,13 @@
   },
   "resources" : [ ],
   "source-url" : "git://github.com/moznion/p6-HTML-Escape.git",
-  "tags" : [ ],
-  "test-depends" : [ ],
-  "version" : "0.0.1"
+  "tags" : [
+      "HTML",
+      "String functions",
+      "Utils"
+  ],
+  "test-depends" : [
+      "Test::META"
+  ],
+  "version" : "0.1.0"
 }

README.md

@@ -27,10 +27,10 @@ Functions
 
 Escapes HTML's special characters in given string.
 
-TODO
-====
+`unescape-html(Str $escaped) returns Str`
+-----------------------------------------
 
-  * Support unescaping function?
+Unescapes HTML's special characters in given string.
 
 SEE ALSO
 ========

lib/HTML/Escape.pm6

@@ -1,4 +1,7 @@
+#! /usr/bin/env false
+
 use v6;
+
 unit class HTML::Escape;
 
 sub escape-html(Str $raw) returns Str is export {
@@ -29,6 +32,39 @@ sub escape-html(Str $raw) returns Str is export {
     ]);
 }
 
+sub unescape-html(Str $escaped) returns Str is export {
+    my Pair @translations = [
+        # Named entities
+        "&" => "&",
+        "'" => "'",
+        "¢" => "¢",
+        "©" => "©",
+        "€" => "€",
+        ">" => ">",
+        "&lt;" => "<",
+        "&pound;" => "£",
+        "&quot;" => "\"",
+        "&reg;" => "®",
+        "&yen;" => "¥",
+
+        # Numbered entities
+        "&#39;" => "'",
+        "&#96;" => "`",
+        "&#123;" => '{',
+        "&#125;" => '}',
+    ];
+
+    my Str @old;
+    my Str @new;
+
+    for @translations -> $translation {
+        @old.push($translation.key);
+        @new.push($translation.value);
+    }
+
+    $escaped.trans(@old => @new);
+}
+
 =begin pod
 
 =head1 NAME

t/02-unescape-single.t

@@ -0,0 +1,33 @@
+#! /usr/bin/env perl6
+
+use v6.c;
+
+use Test;
+use HTML::Escape;
+
+plan 2;
+
+subtest "Unescape named HTML entities" => {
+    plan 11;
+
+    is unescape-html("&"), "&", "Ampersand";
+    is unescape-html("'"), "'", "Single quotation mark (apostrophe)";
+    is unescape-html("¢"), "¢", "Cent";
+    is unescape-html("©"), "©", "Copyright";
+    is unescape-html("€"), "€", "Euro";
+    is unescape-html(">"), ">", "Greater than";
+    is unescape-html("&lt;"), "<", "Less than";
+    is unescape-html("&pound;"), "£", "Pound";
+    is unescape-html("&quot;"), "\"", "Double quotation mark";
+    is unescape-html("&reg;"), "®", "Registered trademark";
+    is unescape-html("&yen;"), "¥", "Yen";
+}
+
+subtest "Unescape numbered HTML entities" => {
+    plan 4;
+
+    is unescape-html("&#39;"), "'", "Single quotation mark (apostrophe)";
+    is unescape-html("&#96;"), "`", "Grave accent (backtick)";
+    is unescape-html("&#123;"), "\{", "Opening brace";
+    is unescape-html("&#125;"), "\}", "Closing brace";
+}

t/03-unescape-string.t

@@ -0,0 +1,17 @@
+#! /usr/bin/env perl6
+
+use v6.c;
+
+use Test;
+use HTML::Escape;
+
+plan 7;
+
+is unescape-html("&lt;^o^&gt;"), "<^o^>";
+is unescape-html("&#39;"), "'";
+is unescape-html("\0&gt;"), "\0>";
+is unescape-html("&#96;"), "`";
+is unescape-html("&#123;&#125;"), '{}';
+
+is unescape-html("&euro;5"), "€5", "Euro mark followed directly by number";
+is unescape-html("It&apos;s an apostrophe!"), "It's an apostrophe!", "Apostrophe used mid-word";