Utility functions cleanup: Cleanup lib/compiler/javascript.js

lib/compiler/javascript.js

@@ -1,53 +1,8 @@
+function hex(ch) { return ch.charCodeAt(0).toString(16).toUpperCase(); }
+
 /* JavaScript code generation helpers. */
 var javascript = {
-  /*
-   * Returns a string padded on the left to a desired length with a character.
-   *
-   * The code needs to be in sync with the code template in the compilation
-   * function for "action" nodes.
-   */
-  padLeft: function(input, padding, length) {
-    var result = input;
-
-    var padLength = length - input.length;
-    for (var i = 0; i < padLength; i++) {
-      result = padding + result;
-    }
-
-    return result;
-  },
-
-  /*
-   * Returns an escape sequence for given character. Uses \x for characters <=
-   * 0xFF to save space, \u for the rest.
-   *
-   * The code needs to be in sync with the code template in the compilation
-   * function for "action" nodes.
-   */
-  escape: function(ch) {
-    var charCode = ch.charCodeAt(0);
-    var escapeChar;
-    var length;
-
-    if (charCode <= 0xFF) {
-      escapeChar = 'x';
-      length = 2;
-    } else {
-      escapeChar = 'u';
-      length = 4;
-    }
-
-    return '\\' + escapeChar + javascript.padLeft(charCode.toString(16).toUpperCase(), '0', length);
-  },
-
-  /*
-   * Surrounds the string with quotes and escapes characters inside so that the
-   * result is a valid JavaScript string.
-   *
-   * The code needs to be in sync with the code template in the compilation
-   * function for "action" nodes.
-   */
-  quote: function(s) {
+  stringEscape: function(s) {
     /*
      * ECMA-262, 5th ed., 7.8.4: All characters may appear literally in a string
      * literal except for the closing quote character, backslash, carriage
@@ -58,23 +13,21 @@ var javascript = {
      * Note that "\0" and "\v" escape sequences are not used because JSHint does
      * not like the first and IE the second.
      */
-    return '"' + s
-      .replace(/\\/g, '\\\\')    // backslash
-      .replace(/"/g, '\\"')      // closing quote character
-      .replace(/\x08/g, '\\b')   // backspace
-      .replace(/\t/g, '\\t')     // horizontal tab
-      .replace(/\n/g, '\\n')     // line feed
-      .replace(/\f/g, '\\f')     // form feed
-      .replace(/\r/g, '\\r')     // carriage return
-      .replace(/[\x00-\x07\x0B\x0E-\x1F\x80-\uFFFF]/g, javascript.escape)
-      + '"';
+    return s
+      .replace(/\\/g,   '\\\\')   // backslash
+      .replace(/"/g,    '\\"')    // closing double quote
+      .replace(/\x08/g, '\\b')    // backspace
+      .replace(/\t/g,   '\\t')    // horizontal tab
+      .replace(/\n/g,   '\\n')    // line feed
+      .replace(/\f/g,   '\\f')    // form feed
+      .replace(/\r/g,   '\\r')    // carriage return
+      .replace(/[\x00-\x07\x0B\x0E\x0F]/g, function(ch) { return '\\x0' + hex(ch); })
+      .replace(/[\x10-\x1F\x80-\xFF]/g,    function(ch) { return '\\x'  + hex(ch); })
+      .replace(/[\u0180-\u0FFF]/g,         function(ch) { return '\\u0' + hex(ch); })
+      .replace(/[\u1080-\uFFFF]/g,         function(ch) { return '\\u'  + hex(ch); });
   },
 
-  /*
-   * Escapes characters inside the string so that it can be used as a list of
-   * characters in a character class of a regular expression.
-   */
-  quoteForRegexpClass: function(s) {
+  regexpClassEscape: function(s) {
     /*
      * Based on ECMA-262, 5th ed., 7.8.5 & 15.10.1.
      *
@@ -92,7 +45,10 @@ var javascript = {
       .replace(/\v/g, '\\x0B')   // vertical tab
       .replace(/\f/g, '\\f')     // form feed
       .replace(/\r/g, '\\r')     // carriage return
-      .replace(/[\x01-\x08\x0E-\x1F\x80-\uFFFF]/g, javascript.escape);
+      .replace(/[\x00-\x08\x0E\x0F]/g,  function(ch) { return '\\x0' + hex(ch); })
+      .replace(/[\x10-\x1F\x80-\xFF]/g, function(ch) { return '\\x'  + hex(ch); })
+      .replace(/[\u0100-\u0FFF]/g,      function(ch) { return '\\u0' + hex(ch); })
+      .replace(/[\u1000-\uFFFF]/g,      function(ch) { return '\\u'  + hex(ch); });
   }
 };
 

lib/compiler/passes/generate-bytecode.js

@@ -285,7 +285,7 @@ function generateBytecode(ast) {
 
     named: function(node, context) {
       var nameIndex = addConst(
-        '{ type: "other", description: ' + js.quote(node.name) + ' }'
+        '{ type: "other", description: "' + js.stringEscape(node.name) + '" }'
       );
 
       /*
@@ -516,15 +516,19 @@ function generateBytecode(ast) {
       var stringIndex, expectedIndex;
 
       if (node.value.length > 0) {
-        stringIndex = addConst(node.ignoreCase
-          ? js.quote(node.value.toLowerCase())
-          : js.quote(node.value)
+        stringIndex = addConst('"'
+          + js.stringEscape(
+              node.ignoreCase ? node.value.toLowerCase() : node.value
+            )
+          + '"'
         );
         expectedIndex = addConst([
           '{',
           'type: "literal",',
-          'value: ' + js.quote(node.value) + ',',
-          'description: ' + js.quote(js.quote(node.value)),
+          'value: "' + js.stringEscape(node.value) + '",',
+          'description: "'
+             + js.stringEscape('"' + js.stringEscape(node.value) + '"')
+             + '"',
           '}'
         ].join(' '));
 
@@ -557,10 +561,10 @@ function generateBytecode(ast) {
           + (node.inverted ? '^' : '')
           + arrays.map(node.parts, function(part) {
               return part instanceof Array
-                ? js.quoteForRegexpClass(part[0])
+                ? js.regexpClassEscape(part[0])
                   + '-'
-                  + js.quoteForRegexpClass(part[1])
-                : js.quoteForRegexpClass(part);
+                  + js.regexpClassEscape(part[1])
+                : js.regexpClassEscape(part);
             }).join('')
           + ']/' + (node.ignoreCase ? 'i' : '');
       } else {
@@ -575,8 +579,8 @@ function generateBytecode(ast) {
       expectedIndex = addConst([
         '{',
         'type: "class",',
-        'value: ' + js.quote(node.rawText) + ',',
-        'description: ' + js.quote(node.rawText),
+        'value: "' + js.stringEscape(node.rawText) + '",',
+        'description: "' + js.stringEscape(node.rawText) + '"',
         '}'
       ].join(' '));
 

lib/compiler/passes/generate-javascript.js

@@ -22,12 +22,12 @@ function generateJavaScript(ast, options) {
            indent2(arrays.map(
              ast.rules,
              function(rule) {
-               return 'peg$decode('
-                     + js.quote(arrays.map(
+               return 'peg$decode("'
+                     + js.stringEscape(arrays.map(
                          rule.bytecode,
                          function(b) { return String.fromCharCode(b + 32); }
                        ).join(''))
-                     + ')';
+                     + '")';
              }
            ).join(',\n')),
         '],'