Add string escape/unescape operations

src/js/config/Categories.js

@@ -167,6 +167,8 @@ var Categories = [
             "Parse UNIX file permissions",
             "Swap endianness",
             "Parse colour code",
+            "Escape String",
+            "Unescape String",
         ]
     },
     {

src/js/config/OperationConfig.js

@@ -2952,5 +2952,19 @@ var OperationConfig = {
                 value: Cipher.SUBS_CIPHERTEXT
             }
         ]
-    }
+    },
+    "Escape String": {
+        description: "Escapes a string so that it can be embedded in another. For example, <code>Don't stop me now</code> becomes <code>Don\\'t stop me now</code>.",
+        run: String_.run_escape,
+        input_type: "string",
+        output_type: "string",
+        args: []
+    },
+    "Unescape String": {
+        description: "Unescapes a string that was embedded inside another so that it can be used in it's own right. For example, <code>Don\\'t stop me now</code> becomes <code>Don't stop me now</code>.",
+        run: String_.run_unescape,
+        input_type: "string",
+        output_type: "string",
+        args: []
+    },
 };

src/js/operations/String.js

@@ -0,0 +1,67 @@
+/**
+ * String operations.
+ * Namespace is appended with an underscore to prevent overwriting the global String object.
+ *
+ * @author Vel0x
+ * @namespace
+ */
+var String_ = {
+
+    /**
+     * @constant
+     * @default
+     */
+    REPLACEMENTS: [
+        {"escaped": "\\\\", "unescaped":"\\"}, // Must be first
+        {"escaped": "\\'", "unescaped":"'"},
+        {"escaped": "\\\"", "unescaped":"\""},
+        {"escaped": "\\n", "unescaped":"\n"},
+        {"escaped": "\\r", "unescaped":"\r"},
+    ],
+
+    /**
+     * Escapes a string for embedding in another string.
+     *
+     * Example: "Don't do that" -> "Don\'t do that"
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run_escape: function(input, args) {
+        return String_._replace_by_keys(input, "unescaped", "escaped")
+    },
+
+    /**
+     * Unescapes a string that was part of another string
+     *
+     * Example: "Don\'t do that" -> "Don't do that"
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run_unescape: function(input, args) {
+        return String_._replace_by_keys(input, "escaped", "unescaped")
+    },
+
+    /**
+     * Replaces all matching tokens in REPLACEMENTS with the correction. The 
+     * ordering is determined by the pattern_key and the replacement_key.
+     *
+     * @param {string} input
+     * @param {string} pattern_key
+     * @param {string} replacement_key
+     * @returns {string}
+     */
+    _replace_by_keys: function(input, pattern_key, replacement_key) {
+        var output = input;
+        var replacementsLength = String_.REPLACEMENTS.length;
+        for (var i = 0; i < replacementsLength; i++) {
+            var replacement = String_.REPLACEMENTS[i];
+            output = output.split(replacement[pattern_key]).join(replacement[replacement_key]);
+        }
+        return output
+    },
+
+};