Compile Codie templates only once

src/emitter.js

@@ -226,37 +226,11 @@ PEG.compiler.emitter = function(ast) {
     return Codie;
   })();
 
-  function formatCode() {
+  var templates = (function() {
-    var args = Array.prototype.slice.call(arguments);
+    var name,
-    var vars = args[args.length - 1] instanceof Object ? args.pop() : {};
+        templates = {},
-
+        sources = {
-    vars.string = quote;
+          grammar: [
-
-    return Codie.template(args.join('\n'))(vars);
-  }
-
-  function resultVar(index) { return "result" + index; }
-  function posVar(index)    { return "pos"    + index; }
-
-  var emit = buildNodeVisitor({
-    grammar: function(node) {
-      var initializerCode = node.initializer !== null
-        ? emit(node.initializer)
-        : "";
-      var name;
-
-      var parseFunctionTableItems = [];
-      for (name in node.rules) {
-        parseFunctionTableItems.push(quote(name) + ": parse_" + name);
-      }
-      parseFunctionTableItems.sort();
-
-      var parseFunctionDefinitions = [];
-      for (name in node.rules) {
-        parseFunctionDefinitions.push(emit(node.rules[name]));
-      }
-
-      return formatCode(
             '(function(){',
             '  /* Generated by PEG.js @VERSION (http://pegjs.majda.cz/). */',
             '  ',
@@ -479,34 +453,9 @@ PEG.compiler.emitter = function(ast) {
             '  result.SyntaxError.prototype = Error.prototype;',
             '  ',
             '  return result;',
-        '})()',
+            '})()'
-        {
+          ],
-          initializerCode:          initializerCode,
+          rule: [
-          parseFunctionTableItems:  parseFunctionTableItems,
-          parseFunctionDefinitions: parseFunctionDefinitions,
-          startRule:                node.startRule
-        }
-      );
-    },
-
-    initializer: function(node) {
-      return node.code;
-    },
-
-    rule: function(node) {
-      var context = {
-        resultIndex: 0,
-        posIndex:    0,
-        delta:       function(resultIndexDelta, posIndexDelta) {
-          return {
-            resultIndex: this.resultIndex + resultIndexDelta,
-            posIndex:    this.posIndex    + posIndexDelta,
-            delta:       this.delta
-          };
-        }
-      };
-
-      return formatCode(
             'function parse_#{node.name}() {',
             '  var cacheKey = "#{node.name}@" + pos;',
             '  var cachedResult = cache[cacheKey];',
@@ -538,15 +487,209 @@ PEG.compiler.emitter = function(ast) {
             '    result:  #{resultVar}',
             '  };',
             '  return #{resultVar};',
+            '}'
+          ],
+          choice: [
+            '#block currentAlternativeCode',
+            '#block nextAlternativesCode'
+          ],
+          "choice.next": [
+            'if (#{resultVar} === null) {',
+            '  #block code',
+            '}'
+          ],
+          sequence: [
+            '#{posVar} = pos;',
+            '#block code'
+          ],
+          "sequence.iteration": [
+            '#block elementCode',
+            'if (#{elementResultVar} !== null) {',
+            '  #block code',
+            '} else {',
+            '  #{resultVar} = null;',
+            '  pos = #{posVar};',
+            '}'
+          ],
+          "sequence.inner": [
+            '#{resultVar} = [#{elementResultVars.join(", ")}];'
+          ],
+          simple_and: [
+            '#{posVar} = pos;',
+            'reportFailures++;',
+            '#block expressionCode',
+            'reportFailures--;',
+            'if (#{resultVar} !== null) {',
+            '  #{resultVar} = "";',
+            '  pos = #{posVar};',
+            '} else {',
+            '  #{resultVar} = null;',
+            '}'
+          ],
+          simple_not: [
+            '#{posVar} = pos;',
+            'reportFailures++;',
+            '#block expressionCode',
+            'reportFailures--;',
+            'if (#{resultVar} === null) {',
+            '  #{resultVar} = "";',
+            '} else {',
+            '  #{resultVar} = null;',
+            '  pos = #{posVar};',
+            '}'
+          ],
+          semantic_and: [
+            '#{resultVar} = (function() {#{node.code}})() ? "" : null;'
+          ],
+          semantic_not: [
+            '#{resultVar} = (function() {#{node.code}})() ? null : "";'
+          ],
+          optional: [
+            '#block expressionCode',
+            '#{resultVar} = #{resultVar} !== null ? #{resultVar} : "";'
+          ],
+          zero_or_more: [
+            '#{resultVar} = [];',
+            '#block expressionCode',
+            'while (#{expressionResultVar} !== null) {',
+            '  #{resultVar}.push(#{expressionResultVar});',
+            '  #block expressionCode',
+            '}'
+          ],
+          one_or_more: [
+            '#block expressionCode',
+            'if (#{expressionResultVar} !== null) {',
+            '  #{resultVar} = [];',
+            '  while (#{expressionResultVar} !== null) {',
+            '    #{resultVar}.push(#{expressionResultVar});',
+            '    #block expressionCode',
+            '  }',
+            '} else {',
+            '  #{resultVar} = null;',
+            '}'
+          ],
+          action: [
+            '#{posVar} = pos;',
+            '#block expressionCode',
+            'if (#{resultVar} !== null) {',
+            '  #{resultVar} = (function(#{formalParams.join(", ")}) {#{node.code}})(#{actualParams.join(", ")});',
             '}',
-        {
+            'if (#{resultVar} === null) {',
+            '  pos = #{posVar};',
+            '}'
+          ],
+          rule_ref: [
+            '#{resultVar} = parse_#{node.name}();'
+          ],
+          literal: [
+            '#if node.value.length === 0',
+            '  #{resultVar} = "";',
+            '#else',
+            '  #if node.value.length === 1',
+            '    if (input.charCodeAt(pos) === #{node.value.charCodeAt(0)}) {',
+            '  #else',
+            '    if (input.substr(pos, #{node.value.length}) === #{string(node.value)}) {',
+            '  #end',
+            '    #{resultVar} = #{string(node.value)};',
+            '    pos += #{node.value.length};',
+            '  } else {',
+            '    #{resultVar} = null;',
+            '    if (reportFailures === 0) {',
+            '      matchFailed(#{string(string(node.value))});',
+            '    }',
+            '  }',
+            '#end'
+          ],
+          any: [
+            'if (input.length > pos) {',
+            '  #{resultVar} = input.charAt(pos);',
+            '  pos++;',
+            '} else {',
+            '  #{resultVar} = null;',
+            '  if (reportFailures === 0) {',
+            '    matchFailed("any character");',
+            '  }',
+            '}'
+          ],
+          "class": [
+            'if (#{regexp}.test(input.charAt(pos))) {',
+            '  #{resultVar} = input.charAt(pos);',
+            '  pos++;',
+            '} else {',
+            '  #{resultVar} = null;',
+            '  if (reportFailures === 0) {',
+            '    matchFailed(#{string(node.rawText)});',
+            '  }',
+            '}'
+          ]
+        };
+
+    for (name in sources) {
+      templates[name] = Codie.template(sources[name].join('\n'));
+    }
+
+    return templates;
+  })();
+
+  function fill(name, vars) {
+    vars.string = quote;
+
+    return templates[name](vars);
+  }
+
+  function resultVar(index) { return "result" + index; }
+  function posVar(index)    { return "pos"    + index; }
+
+  var emit = buildNodeVisitor({
+    grammar: function(node) {
+      var initializerCode = node.initializer !== null
+        ? emit(node.initializer)
+        : "";
+      var name;
+
+      var parseFunctionTableItems = [];
+      for (name in node.rules) {
+        parseFunctionTableItems.push(quote(name) + ": parse_" + name);
+      }
+      parseFunctionTableItems.sort();
+
+      var parseFunctionDefinitions = [];
+      for (name in node.rules) {
+        parseFunctionDefinitions.push(emit(node.rules[name]));
+      }
+
+      return fill("grammar", {
+        initializerCode:          initializerCode,
+        parseFunctionTableItems:  parseFunctionTableItems,
+        parseFunctionDefinitions: parseFunctionDefinitions,
+        startRule:                node.startRule
+      });
+    },
+
+    initializer: function(node) {
+      return node.code;
+    },
+
+    rule: function(node) {
+      var context = {
+        resultIndex: 0,
+        posIndex:    0,
+        delta:       function(resultIndexDelta, posIndexDelta) {
+          return {
+            resultIndex: this.resultIndex + resultIndexDelta,
+            posIndex:    this.posIndex    + posIndexDelta,
+            delta:       this.delta
+          };
+        }
+      };
+
+      return fill("rule", {
         node:       node,
         resultVars: map(range(node.resultStackDepth), resultVar),
         posVars:    map(range(node.posStackDepth), posVar),
         code:       emit(node.expression, context),
         resultVar:  resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     /*
@@ -584,24 +727,15 @@ PEG.compiler.emitter = function(ast) {
 
       for (var i = node.alternatives.length - 1; i >= 0; i--) {
         nextAlternativesCode = i !== node.alternatives.length - 1
-          ? formatCode(
+          ? fill("choice.next", {
-              'if (#{resultVar} === null) {',
-              '  #block code',
-              '}',
-              {
               code:      code,
               resultVar: resultVar(context.resultIndex)
-              }
+            })
-            )
           : '';
-        code = formatCode(
+        code = fill("choice", {
-          '#block currentAlternativeCode',
-          '#block nextAlternativesCode',
-          {
           currentAlternativeCode: emit(node.alternatives[i], context),
           nextAlternativesCode:   nextAlternativesCode
-          }
+        });
-        );
       }
 
       return code;
@@ -612,41 +746,22 @@ PEG.compiler.emitter = function(ast) {
         return resultVar(context.resultIndex + i);
       });
 
-      var code = formatCode(
+      var code = fill("sequence.inner", {
-        '#{resultVar} = [#{elementResultVars.join(", ")}];',
-        {
         resultVar:         resultVar(context.resultIndex),
         elementResultVars: elementResultVars
-        }
+      });
-      );
 
       for (var i = node.elements.length - 1; i >= 0; i--) {
-        code = formatCode(
+        code = fill("sequence.iteration", {
-          '#block elementCode',
-          'if (#{elementResultVar} !== null) {',
-          '  #block code',
-          '} else {',
-          '  #{resultVar} = null;',
-          '  pos = #{posVar};',
-          '}',
-          {
           elementCode:      emit(node.elements[i], context.delta(i, 1)),
           elementResultVar: elementResultVars[i],
           code:             code,
           posVar:           posVar(context.posIndex),
           resultVar:        resultVar(context.resultIndex)
-          }
+        });
-        );
       }
 
-      return formatCode(
+      return fill("sequence", { code: code, posVar: posVar(context.posIndex) });
-        '#{posVar} = pos;',
-        '#block code',
-        {
-          code:   code,
-          posVar: posVar(context.posIndex)
-        }
-      );
     },
 
     labeled: function(node, context) {
@@ -654,110 +769,56 @@ PEG.compiler.emitter = function(ast) {
     },
 
     simple_and: function(node, context) {
-      return formatCode(
+      return fill("simple_and", {
-        '#{posVar} = pos;',
-        'reportFailures++;',
-        '#block expressionCode',
-        'reportFailures--;',
-        'if (#{resultVar} !== null) {',
-        '  #{resultVar} = "";',
-        '  pos = #{posVar};',
-        '} else {',
-        '  #{resultVar} = null;',
-        '}',
-        {
         expressionCode: emit(node.expression, context.delta(0, 1)),
         posVar:         posVar(context.posIndex),
         resultVar:      resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     simple_not: function(node, context) {
-      return formatCode(
+      return fill("simple_not", {
-        '#{posVar} = pos;',
-        'reportFailures++;',
-        '#block expressionCode',
-        'reportFailures--;',
-        'if (#{resultVar} === null) {',
-        '  #{resultVar} = "";',
-        '} else {',
-        '  #{resultVar} = null;',
-        '  pos = #{posVar};',
-        '}',
-        {
         expressionCode: emit(node.expression, context.delta(0, 1)),
         posVar:         posVar(context.posIndex),
         resultVar:      resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     semantic_and: function(node, context) {
-      return formatCode(
+      return fill("semantic_and", {
-        '#{resultVar} = (function() {#{node.code}})() ? "" : null;',
-        {
         node:      node,
         resultVar: resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     semantic_not: function(node, context) {
-      return formatCode(
+      return fill("semantic_not", {
-        '#{resultVar} = (function() {#{node.code}})() ? null : "";',
-        {
         node:      node,
         resultVar: resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     optional: function(node, context) {
-      return formatCode(
+      return fill("optional", {
-        '#block expressionCode',
-        '#{resultVar} = #{resultVar} !== null ? #{resultVar} : "";',
-        {
         expressionCode: emit(node.expression, context),
         resultVar:      resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     zero_or_more: function(node, context) {
-      return formatCode(
+      return fill("zero_or_more", {
-        '#{resultVar} = [];',
-        '#block expressionCode',
-        'while (#{expressionResultVar} !== null) {',
-        '  #{resultVar}.push(#{expressionResultVar});',
-        '  #block expressionCode',
-        '}',
-        {
         expressionCode:      emit(node.expression, context.delta(1, 0)),
         expressionResultVar: resultVar(context.resultIndex + 1),
         resultVar:           resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     one_or_more: function(node, context) {
-      return formatCode(
+      return fill("one_or_more", {
-        '#block expressionCode',
-        'if (#{expressionResultVar} !== null) {',
-        '  #{resultVar} = [];',
-        '  while (#{expressionResultVar} !== null) {',
-        '    #{resultVar}.push(#{expressionResultVar});',
-        '    #block expressionCode',
-        '  }',
-        '} else {',
-        '  #{resultVar} = null;',
-        '}',
-        {
         expressionCode:      emit(node.expression, context.delta(1, 0)),
         expressionResultVar: resultVar(context.resultIndex + 1),
         resultVar:           resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     action: function(node, context) {
@@ -793,75 +854,32 @@ PEG.compiler.emitter = function(ast) {
         actualParams = [];
       }
 
-      return formatCode(
+      return fill("action", {
-        '#{posVar} = pos;',
-        '#block expressionCode',
-        'if (#{resultVar} !== null) {',
-        '  #{resultVar} = (function(#{formalParams.join(", ")}) {#{node.code}})(#{actualParams.join(", ")});',
-        '}',
-        'if (#{resultVar} === null) {',
-        '  pos = #{posVar};',
-        '}',
-        {
         node:           node,
         expressionCode: emit(node.expression, context.delta(0, 1)),
         formalParams:   formalParams,
         actualParams:   actualParams,
         posVar:         posVar(context.posIndex),
         resultVar:      resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     rule_ref: function(node, context) {
-      return formatCode(
+      return fill("rule_ref", {
-        '#{resultVar} = parse_#{node.name}();',
-        {
         node:      node,
         resultVar: resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     literal: function(node, context) {
-      return formatCode(
+      return fill("literal", {
-        '#if node.value.length === 0',
-        '  #{resultVar} = "";',
-        '#else',
-        '  #if node.value.length === 1',
-        '    if (input.charCodeAt(pos) === #{node.value.charCodeAt(0)}) {',
-        '  #else',
-        '    if (input.substr(pos, #{node.value.length}) === #{string(node.value)}) {',
-        '  #end',
-        '    #{resultVar} = #{string(node.value)};',
-        '    pos += #{node.value.length};',
-        '  } else {',
-        '    #{resultVar} = null;',
-        '    if (reportFailures === 0) {',
-        '      matchFailed(#{string(string(node.value))});',
-        '    }',
-        '  }',
-        '#end',
-        {
         node:      node,
         resultVar: resultVar(context.resultIndex)
-        }
+      });
-      );
     },
 
     any: function(node, context) {
-      return formatCode(
+      return fill("any", { resultVar: resultVar(context.resultIndex) });
-        'if (input.length > pos) {',
-        '  #{resultVar} = input.charAt(pos);',
-        '  pos++;',
-        '} else {',
-        '  #{resultVar} = null;',
-        '  if (reportFailures === 0) {',
-        '    matchFailed("any character");',
-        '  }',
-        '}',
-        { resultVar: resultVar(context.resultIndex) }
-      );
     },
 
     "class": function(node, context) {
@@ -886,22 +904,11 @@ PEG.compiler.emitter = function(ast) {
         regexp = node.inverted ? '/^[\\S\\s]/' : '/^(?!)/';
       }
 
-      return formatCode(
+      return fill("class", {
-        'if (#{regexp}.test(input.charAt(pos))) {',
-        '  #{resultVar} = input.charAt(pos);',
-        '  pos++;',
-        '} else {',
-        '  #{resultVar} = null;',
-        '  if (reportFailures === 0) {',
-        '    matchFailed(#{string(node.rawText)});',
-        '  }',
-        '}',
-        {
         node:      node,
         regexp:    regexp,
         resultVar: resultVar(context.resultIndex)
-        }
+      });
-      );
     }
   });