Reviewers: Lasse Reichstein, Description: Simplify Join and speedup joining arrays of numbers.
Please review this at http://codereview.chromium.org/6173004/ SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/ Affected files: M src/array.js Index: src/array.js =================================================================== --- src/array.js (revision 6240) +++ src/array.js (working copy) @@ -117,22 +117,19 @@ // Fast case for one-element arrays. if (length == 1) { var e = array[0]; - if (!IS_UNDEFINED(e) || (0 in array)) { - if (IS_STRING(e)) return e; - return convert(e); - } - return ''; + if (IS_STRING(e)) return e; + return convert(e); } // Construct an array for the elements. var elements = new $Array(length); - var elements_length = 0; // We pull the empty separator check outside the loop for speed! if (separator.length == 0) { + var elements_length = 0; for (var i = 0; i < length; i++) { var e = array[i]; - if (!IS_UNDEFINED(e)) { + if (!(e == null)) { if (!IS_STRING(e)) e = convert(e); elements[elements_length++] = e; } @@ -143,15 +140,23 @@ return %StringBuilderConcat(elements, elements_length, ''); } // Non-empty separator. - for (var i = 0; i < length; i++) { - var e = array[i]; - if (!IS_UNDEFINED(e)) { + if (!IS_NUMBER(array[0])) { + for (var i = 0; i < length; i++) { + var e = array[i]; if (!IS_STRING(e)) e = convert(e); elements[i] = e; - } else { - elements[i] = ''; } - } + } else { + for (var i = 0; i < length; i++) { + var e = array[i]; + if (IS_NUMBER(e)) { + elements[i] = %_NumberToString(e); + } else { + if (!IS_STRING(e)) e = convert(e); + elements[i] = e; + } + } + } var result = %_FastAsciiArrayJoin(elements, separator); if (!IS_UNDEFINED(result)) return result; -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev
