Use |charCodeAt| instead of |charCode| when matching one-character literals

The speedup is marginal (if any) but let's have this anyway. Speed impact ------------ Before: 212.49 kB/s After: 213.01 kB/s Difference: 0.24% Size impact ----------- Before: 1056976 b After: 1058314 b Difference: 0.12% (Measured by /tools/impact with Node.js v0.4.8 on x86_64 GNU/Linux.) Closes GH-50.
13 years ago · 468597be27
parent d3aff0c66a
commit 468597be27
2 changed files with 60 additions and 51 deletions
--- a/src/emitter.js
+++ b/src/emitter.js
@ -693,12 +693,21 @@ PEG.compiler.emitter = function(ast) {

    literal: function(node, context) {
      var length = node.value.length;
-      var extractSubstrCode = length === 1
-        ? "input.charAt(pos)"
-        : "input.substr(pos, " + length + ")";
+      var testCode = length === 1
+        ? formatCode(
+            "input.charCodeAt(pos) === ${valueCharCode}",
+            { valueCharCode: node.value.charCodeAt(0) }
+          )
+        : formatCode(
+            "input.substr(pos, ${length}) === ${value|string}",
+            {
+              value:  node.value,
+              length: length
+            }
+          );

      return formatCode(
-        "if (${extractSubstrCode} === ${value|string}) {",
+        "if (${testCode}) {",
        "  ${resultVar} = ${value|string};",
        "  pos += ${length};",
        "} else {",
@ -708,11 +717,11 @@ PEG.compiler.emitter = function(ast) {
        "  }",
        "}",
        {
-          extractSubstrCode: extractSubstrCode,
-          value:             node.value,
-          valueQuoted:       quote(node.value),
-          length:            length,
-          resultVar:         resultVar(context.resultIndex)
+          testCode:    testCode,
+          value:       node.value,
+          valueQuoted: quote(node.value),
+          length:      length,
+          resultVar:   resultVar(context.resultIndex)
        }
      );
    },
--- a/src/parser.js
+++ b/src/parser.js
@ -1006,7 +1006,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "{") {
+        if (input.charCodeAt(pos) === 123) {
          result0 = "{";
          pos += 1;
        } else {
@ -1031,7 +1031,7 @@ PEG.parser = (function(){
            }
          }
          if (result1 !== null) {
-            if (input.charAt(pos) === "}") {
+            if (input.charCodeAt(pos) === 125) {
              result2 = "}";
              pos += 1;
            } else {
@ -1156,7 +1156,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "=") {
+        if (input.charCodeAt(pos) === 61) {
          result0 = "=";
          pos += 1;
        } else {
@ -1207,7 +1207,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === ":") {
+        if (input.charCodeAt(pos) === 58) {
          result0 = ":";
          pos += 1;
        } else {
@ -1258,7 +1258,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === ";") {
+        if (input.charCodeAt(pos) === 59) {
          result0 = ";";
          pos += 1;
        } else {
@ -1309,7 +1309,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "/") {
+        if (input.charCodeAt(pos) === 47) {
          result0 = "/";
          pos += 1;
        } else {
@ -1360,7 +1360,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "&") {
+        if (input.charCodeAt(pos) === 38) {
          result0 = "&";
          pos += 1;
        } else {
@ -1411,7 +1411,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "!") {
+        if (input.charCodeAt(pos) === 33) {
          result0 = "!";
          pos += 1;
        } else {
@ -1462,7 +1462,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "?") {
+        if (input.charCodeAt(pos) === 63) {
          result0 = "?";
          pos += 1;
        } else {
@ -1513,7 +1513,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "*") {
+        if (input.charCodeAt(pos) === 42) {
          result0 = "*";
          pos += 1;
        } else {
@ -1564,7 +1564,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "+") {
+        if (input.charCodeAt(pos) === 43) {
          result0 = "+";
          pos += 1;
        } else {
@ -1615,7 +1615,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "(") {
+        if (input.charCodeAt(pos) === 40) {
          result0 = "(";
          pos += 1;
        } else {
@ -1666,7 +1666,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === ")") {
+        if (input.charCodeAt(pos) === 41) {
          result0 = ")";
          pos += 1;
        } else {
@ -1717,7 +1717,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === ".") {
+        if (input.charCodeAt(pos) === 46) {
          result0 = ".";
          pos += 1;
        } else {
@ -1770,7 +1770,7 @@ PEG.parser = (function(){
        pos1 = pos;
        result0 = parse_letter();
        if (result0 === null) {
-          if (input.charAt(pos) === "_") {
+          if (input.charCodeAt(pos) === 95) {
            result0 = "_";
            pos += 1;
          } else {
@ -1780,7 +1780,7 @@ PEG.parser = (function(){
            }
          }
          if (result0 === null) {
-            if (input.charAt(pos) === "$") {
+            if (input.charCodeAt(pos) === 36) {
              result0 = "$";
              pos += 1;
            } else {
@ -1798,7 +1798,7 @@ PEG.parser = (function(){
          if (result2 === null) {
            result2 = parse_digit();
            if (result2 === null) {
-              if (input.charAt(pos) === "_") {
+              if (input.charCodeAt(pos) === 95) {
                result2 = "_";
                pos += 1;
              } else {
@ -1808,7 +1808,7 @@ PEG.parser = (function(){
                }
              }
              if (result2 === null) {
-                if (input.charAt(pos) === "$") {
+                if (input.charCodeAt(pos) === 36) {
                  result2 = "$";
                  pos += 1;
                } else {
@ -1827,7 +1827,7 @@ PEG.parser = (function(){
            if (result2 === null) {
              result2 = parse_digit();
              if (result2 === null) {
-                if (input.charAt(pos) === "_") {
+                if (input.charCodeAt(pos) === 95) {
                  result2 = "_";
                  pos += 1;
                } else {
@ -1837,7 +1837,7 @@ PEG.parser = (function(){
                  }
                }
                if (result2 === null) {
-                  if (input.charAt(pos) === "$") {
+                  if (input.charCodeAt(pos) === 36) {
                    result2 = "$";
                    pos += 1;
                  } else {
@ -1950,7 +1950,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "\"") {
+        if (input.charCodeAt(pos) === 34) {
          result0 = "\"";
          pos += 1;
        } else {
@ -1967,7 +1967,7 @@ PEG.parser = (function(){
            result2 = parse_doubleQuotedCharacter();
          }
          if (result1 !== null) {
-            if (input.charAt(pos) === "\"") {
+            if (input.charCodeAt(pos) === 34) {
              result2 = "\"";
              pos += 1;
            } else {
@ -2061,7 +2061,7 @@ PEG.parser = (function(){
        pos1 = pos;
        pos2 = pos;
        reportFailures++;
-        if (input.charAt(pos) === "\"") {
+        if (input.charCodeAt(pos) === 34) {
          result0 = "\"";
          pos += 1;
        } else {
@ -2071,7 +2071,7 @@ PEG.parser = (function(){
          }
        }
        if (result0 === null) {
-          if (input.charAt(pos) === "\\") {
+          if (input.charCodeAt(pos) === 92) {
            result0 = "\\";
            pos += 1;
          } else {
@ -2142,7 +2142,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "'") {
+        if (input.charCodeAt(pos) === 39) {
          result0 = "'";
          pos += 1;
        } else {
@ -2159,7 +2159,7 @@ PEG.parser = (function(){
            result2 = parse_singleQuotedCharacter();
          }
          if (result1 !== null) {
-            if (input.charAt(pos) === "'") {
+            if (input.charCodeAt(pos) === 39) {
              result2 = "'";
              pos += 1;
            } else {
@ -2253,7 +2253,7 @@ PEG.parser = (function(){
        pos1 = pos;
        pos2 = pos;
        reportFailures++;
-        if (input.charAt(pos) === "'") {
+        if (input.charCodeAt(pos) === 39) {
          result0 = "'";
          pos += 1;
        } else {
@ -2263,7 +2263,7 @@ PEG.parser = (function(){
          }
        }
        if (result0 === null) {
-          if (input.charAt(pos) === "\\") {
+          if (input.charCodeAt(pos) === 92) {
            result0 = "\\";
            pos += 1;
          } else {
@ -2334,7 +2334,7 @@ PEG.parser = (function(){
        reportFailures++;
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "[") {
+        if (input.charCodeAt(pos) === 91) {
          result0 = "[";
          pos += 1;
        } else {
@ -2344,7 +2344,7 @@ PEG.parser = (function(){
          }
        }
        if (result0 !== null) {
-          if (input.charAt(pos) === "^") {
+          if (input.charCodeAt(pos) === 94) {
            result1 = "^";
            pos += 1;
          } else {
@ -2370,7 +2370,7 @@ PEG.parser = (function(){
              }
            }
            if (result2 !== null) {
-              if (input.charAt(pos) === "]") {
+              if (input.charCodeAt(pos) === 93) {
                result3 = "]";
                pos += 1;
              } else {
@ -2451,7 +2451,7 @@ PEG.parser = (function(){
        pos1 = pos;
        result0 = parse_classCharacter();
        if (result0 !== null) {
-          if (input.charAt(pos) === "-") {
+          if (input.charCodeAt(pos) === 45) {
            result1 = "-";
            pos += 1;
          } else {
@ -2595,7 +2595,7 @@ PEG.parser = (function(){
        pos1 = pos;
        pos2 = pos;
        reportFailures++;
-        if (input.charAt(pos) === "]") {
+        if (input.charCodeAt(pos) === 93) {
          result0 = "]";
          pos += 1;
        } else {
@ -2605,7 +2605,7 @@ PEG.parser = (function(){
          }
        }
        if (result0 === null) {
-          if (input.charAt(pos) === "\\") {
+          if (input.charCodeAt(pos) === 92) {
            result0 = "\\";
            pos += 1;
          } else {
@ -2676,7 +2676,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "\\") {
+        if (input.charCodeAt(pos) === 92) {
          result0 = "\\";
          pos += 1;
        } else {
@ -2690,7 +2690,7 @@ PEG.parser = (function(){
          reportFailures++;
          result1 = parse_digit();
          if (result1 === null) {
-            if (input.charAt(pos) === "x") {
+            if (input.charCodeAt(pos) === 120) {
              result1 = "x";
              pos += 1;
            } else {
@ -2700,7 +2700,7 @@ PEG.parser = (function(){
              }
            }
            if (result1 === null) {
-              if (input.charAt(pos) === "u") {
+              if (input.charCodeAt(pos) === 117) {
                result1 = "u";
                pos += 1;
              } else {
@ -2974,7 +2974,7 @@ PEG.parser = (function(){
        
        pos0 = pos;
        pos1 = pos;
-        if (input.charAt(pos) === "\\") {
+        if (input.charCodeAt(pos) === 92) {
          result0 = "\\";
          pos += 1;
        } else {
@ -3493,7 +3493,7 @@ PEG.parser = (function(){
        var pos0;
        
        reportFailures++;
-        if (input.charAt(pos) === "\n") {
+        if (input.charCodeAt(pos) === 10) {
          result0 = "\n";
          pos += 1;
        } else {
@ -3513,7 +3513,7 @@ PEG.parser = (function(){
            }
          }
          if (result0 === null) {
-            if (input.charAt(pos) === "\r") {
+            if (input.charCodeAt(pos) === 13) {
              result0 = "\r";
              pos += 1;
            } else {
@ -3523,7 +3523,7 @@ PEG.parser = (function(){
              }
            }
            if (result0 === null) {
-              if (input.charAt(pos) === "\u2028") {
+              if (input.charCodeAt(pos) === 8232) {
                result0 = "\u2028";
                pos += 1;
              } else {
@ -3533,7 +3533,7 @@ PEG.parser = (function(){
                }
              }
              if (result0 === null) {
-                if (input.charAt(pos) === "\u2029") {
+                if (input.charCodeAt(pos) === 8233) {
                  result0 = "\u2029";
                  pos += 1;
                } else {