Function lex

public/javascripts/socket.io.js:2525–2680

()

	        // the end of the source string. A token may be a string, number, `null`
	        // literal, or Boolean literal.
	        var lex = function () {
	          var source = Source, length = source.length, value, begin, position, isSigned, charCode;
	          while (Index < length) {
	            charCode = source.charCodeAt(Index);
	            switch (charCode) {
	              case 9: case 10: case 13: case 32:
	                // Skip whitespace tokens, including tabs, carriage returns, line
	                // feeds, and space characters.
	                Index++;
	                break;
	              case 123: case 125: case 91: case 93: case 58: case 44:
	                // Parse a punctuator token (`{`, `}`, `[`, `]`, `:`, or `,`) at
	                // the current position.
	                value = charIndexBuggy ? source.charAt(Index) : source[Index];
	                Index++;
	                return value;
	              case 34:
	                // `"` delimits a JSON string; advance to the next character and
	                // begin parsing the string. String tokens are prefixed with the
	                // sentinel `@` character to distinguish them from punctuators and
	                // end-of-string tokens.
	                for (value = "@", Index++; Index < length;) {
	                  charCode = source.charCodeAt(Index);
	                  if (charCode < 32) {
	                    // Unescaped ASCII control characters (those with a code unit
	                    // less than the space character) are not permitted.
	                    abort();
	                  } else if (charCode == 92) {
	                    // A reverse solidus (`\`) marks the beginning of an escaped
	                    // control character (including `"`, `\`, and `/`) or Unicode
	                    // escape sequence.
	                    charCode = source.charCodeAt(++Index);
	                    switch (charCode) {
	                      case 92: case 34: case 47: case 98: case 116: case 110: case 102: case 114:
	                        // Revive escaped control characters.
	                        value += Unescapes[charCode];
	                        Index++;
	                        break;
	                      case 117:
	                        // `\u` marks the beginning of a Unicode escape sequence.
	                        // Advance to the first character and validate the
	                        // four-digit code point.
	                        begin = ++Index;
	                        for (position = Index + 4; Index < position; Index++) {
	                          charCode = source.charCodeAt(Index);
	                          // A valid sequence comprises four hexdigits (case-
	                          // insensitive) that form a single hexadecimal value.
	                          if (!(charCode >= 48 && charCode <= 57 || charCode >= 97 && charCode <= 102 || charCode >= 65 && charCode <= 70)) {
	                            // Invalid Unicode escape sequence.
	                            abort();
	                          }
	                        }
	                        // Revive the escaped character.
	                        value += fromCharCode("0x" + source.slice(begin, Index));
	                        break;
	                      default:
	                        // Invalid escape sequence.
	                        abort();