optimize scanString to not run the regex more than once

1 files changed, 5 insertions, 7 deletions

diff --git a/src/library.js b/src/library.js
index a2d3244e..6eab2587 100644
--- a/src/library.js
+++ b/src/library.js
@@ -1579,12 +1579,12 @@ LibraryManager.library = {
   // stdio.h
   // ==========================================================================
 
-  _isFloat: function(text) {
-    return !!(/^[+-]?[0-9]*\.?[0-9]+([eE][+-]?[0-9]+)?$/.exec(text));
+  _getFloat: function(text) {
+    return /^[+-]?[0-9]*\.?[0-9]+([eE][+-]?[0-9]+)?/.exec(text);
   },
 
   // TODO: Document.
-  _scanString__deps: ['_isFloat'],
+  _scanString__deps: ['_getFloat'],
   _scanString: function(format, get, unget, varargs) {
     if (!__scanString.whiteSpace) {
       __scanString.whiteSpace = {};
@@ -1743,15 +1743,13 @@ LibraryManager.library = {
         // Read characters according to the format. floats are trickier, they may be in an unfloat state in the middle, then be a valid float later
         if (type == 'f' || type == 'e' || type == 'g' ||
             type == 'F' || type == 'E' || type == 'G') {
-          var last = 0;
           next = get();
           while (next > 0 && (!(next in __scanString.whiteSpace)))  {
             buffer.push(String.fromCharCode(next));
-            if (__isFloat(buffer.join(''))) {
-              last = buffer.length;
-            }
             next = get();
           }
+          var m = __getFloat(buffer.join(''));
+          var last = m ? m[0].length : 0;
           for (var i = 0; i < buffer.length - last + 1; i++) {
             unget();
           }