Converted the core to ES modules

src/core/operations/legacy/Unicode.js

@@ -0,0 +1,101 @@
+import Utils from "../Utils.js";
+
+
+/**
+ * Unicode operations.
+ *
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ *
+ * @namespace
+ */
+const Unicode = {
+
+    /**
+     * @constant
+     * @default
+     */
+    PREFIXES: ["\\u", "%u", "U+"],
+
+    /**
+     * Unescape Unicode Characters operation.
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runUnescape: function(input, args) {
+        let prefix = Unicode._prefixToRegex[args[0]],
+            regex = new RegExp(prefix+"([a-f\\d]{4})", "ig"),
+            output = "",
+            m,
+            i = 0;
+
+        while ((m = regex.exec(input))) {
+            // Add up to match
+            output += input.slice(i, m.index);
+            i = m.index;
+
+            // Add match
+            output += Utils.chr(parseInt(m[1], 16));
+
+            i = regex.lastIndex;
+        }
+
+        // Add all after final match
+        output += input.slice(i, input.length);
+
+        return output;
+    },
+
+
+    /**
+     * Escape Unicode Characters operation.
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runEscape: function(input, args) {
+        const regexWhitelist = /[ -~]/i,
+            prefix = args[0],
+            encodeAll = args[1],
+            padding = args[2],
+            uppercaseHex = args[3];
+
+        let output = "",
+            character = "";
+
+        for (let i = 0; i < input.length; i++) {
+            character = input[i];
+            if (!encodeAll && regexWhitelist.test(character)) {
+                // It’s a printable ASCII character so don’t escape it.
+                output += character;
+                continue;
+            }
+
+            let cp = character.codePointAt(0).toString(16);
+            if (uppercaseHex) cp = cp.toUpperCase();
+            output += prefix + cp.padStart(padding, "0");
+        }
+
+        return output;
+    },
+
+
+    /**
+     * Lookup table to add prefixes to unicode delimiters so that they can be used in a regex.
+     *
+     * @private
+     * @constant
+     */
+    _prefixToRegex: {
+        "\\u": "\\\\u",
+        "%u": "%u",
+        "U+": "U\\+"
+    },
+
+};
+
+export default Unicode;