optimized simple escaped chars lookup

cray0000 · Jul 7, 2014 · 284c019 · 284c019
1 parent e4aeff5
commit 284c019
Showing 1 changed file with 9 additions and 2 deletions.
diff --git a/lib/js-yaml/loader.js b/lib/js-yaml/loader.js
@@ -103,6 +103,13 @@ function simpleEscapeSequence(c) {
         (c === 0x50/* P */) ? '\u2029' : '';
 }
 
+var simpleEscapeCheck = new Array(256); // integer, for fast access
+var simpleEscapeMap = new Array(256);
+for (var i = 0; i < 256; i++) {
+  simpleEscapeCheck[i] = simpleEscapeSequence(i) ? 1 : 0;
+  simpleEscapeMap[i] = simpleEscapeSequence(i);
+}
+
 
 function State(input, options) {
   this.input = input;
@@ -561,8 +568,8 @@ function readDoubleQuotedScalar(state, nodeIndent) {
         skipSeparationSpace(state, false, nodeIndent);
 
         //TODO: rework to inline fn with no type cast?
-      } else if ((tmpEsc = simpleEscapeSequence(ch)) !== '') {
-        state.result += tmpEsc;
+      } else if (ch < 256 && simpleEscapeCheck[ch]) {
+        state.result += simpleEscapeMap[ch];
         state.position++;
 
       } else if ((tmp = escapedHexLen(ch)) > 0) {