Split internal 'is' function into regex vs charclass usage.

Prevents costly Object.prototype.toString call. Switch from !!regex.match to regex.test for ~10% improvement.
isaacs · Jan 17, 2017 · b9d12be · b9d12be
1 parent 7a3ad9d
commit b9d12be
Showing 1 changed file with 16 additions and 12 deletions.
diff --git a/lib/sax.js b/lib/sax.js
@@ -307,12 +307,16 @@
     }, {})
   }
 
-  function isRegExp (c) {
-    return Object.prototype.toString.call(c) === '[object RegExp]'
+  function isMatch (regex, c) {
+    return regex.test(c)
   }
 
   function is (charclass, c) {
-    return isRegExp(charclass) ? !!c.match(charclass) : charclass[c]
+    return charclass[c]
+  }
+
+  function notMatch (regex, c) {
+    return !isMatch(regex, c)
   }
 
   function not (charclass, c) {
@@ -1080,7 +1084,7 @@
             parser.sgmlDecl = ''
           } else if (is(whitespace, c)) {
             // wait for it...
-          } else if (is(nameStart, c)) {
+          } else if (isMatch(nameStart, c)) {
             parser.state = S.OPEN_TAG
             parser.tagName = c
           } else if (c === '/') {
@@ -1283,7 +1287,7 @@
           continue
 
         case S.OPEN_TAG:
-          if (is(nameBody, c)) {
+          if (isMatch(nameBody, c)) {
             parser.tagName += c
           } else {
             newTag(parser)
@@ -1318,7 +1322,7 @@
             openTag(parser)
           } else if (c === '/') {
             parser.state = S.OPEN_TAG_SLASH
-          } else if (is(nameStart, c)) {
+          } else if (isMatch(nameStart, c)) {
             parser.attribName = c
             parser.attribValue = ''
             parser.state = S.ATTRIB_NAME
@@ -1337,7 +1341,7 @@
             openTag(parser)
           } else if (is(whitespace, c)) {
             parser.state = S.ATTRIB_NAME_SAW_WHITE
-          } else if (is(nameBody, c)) {
+          } else if (isMatch(nameBody, c)) {
             parser.attribName += c
           } else {
             strictFail(parser, 'Invalid attribute name')
@@ -1360,7 +1364,7 @@
             parser.attribName = ''
             if (c === '>') {
               openTag(parser)
-            } else if (is(nameStart, c)) {
+            } else if (isMatch(nameStart, c)) {
               parser.attribName = c
               parser.state = S.ATTRIB_NAME
             } else {
@@ -1404,7 +1408,7 @@
             openTag(parser)
           } else if (c === '/') {
             parser.state = S.OPEN_TAG_SLASH
-          } else if (is(nameStart, c)) {
+          } else if (isMatch(nameStart, c)) {
             strictFail(parser, 'No whitespace between attributes')
             parser.attribName = c
             parser.attribValue = ''
@@ -1435,7 +1439,7 @@
           if (!parser.tagName) {
             if (is(whitespace, c)) {
               continue
-            } else if (not(nameStart, c)) {
+            } else if (notMatch(nameStart, c)) {
               if (parser.script) {
                 parser.script += '</' + c
                 parser.state = S.SCRIPT
@@ -1447,7 +1451,7 @@
             }
           } else if (c === '>') {
             closeTag(parser)
-          } else if (is(nameBody, c)) {
+          } else if (isMatch(nameBody, c)) {
             parser.tagName += c
           } else if (parser.script) {
             parser.script += '</' + parser.tagName
@@ -1498,7 +1502,7 @@
             parser[buffer] += parseEntity(parser)
             parser.entity = ''
             parser.state = returnState
-          } else if (is(parser.entity.length ? entityBody : entityStart, c)) {
+          } else if (isMatch(parser.entity.length ? entityBody : entityStart, c)) {
             parser.entity += c
           } else {
             strictFail(parser, 'Invalid character in entity name')