Merge pull request #412 from wycats/inline-ops

Inline ops

1 files changed, 217 insertions, 70 deletions

diff --git a/lib/handlebars/compiler/compiler.js b/lib/handlebars/compiler/compiler.js
index 9bcc065..0d21739 100644
--- a/lib/handlebars/compiler/compiler.js
+++ b/lib/handlebars/compiler/compiler.js
@@ -38,6 +38,26 @@ Handlebars.JavaScriptCompiler = function() {};
 
       return out.join("\n");
     },
+    equals: function(other) {
+      var len = this.opcodes.length;
+      if (other.opcodes.length !== len) {
+        return false;
+      }
+
+      for (var i = 0; i < len; i++) {
+        var opcode = this.opcodes[i],
+            otherOpcode = other.opcodes[i];
+        if (opcode.opcode !== otherOpcode.opcode || opcode.args.length !== otherOpcode.args.length) {
+          return false;
+        }
+        for (var j = 0; j < opcode.args.length; j++) {
+          if (opcode.args[j] !== otherOpcode.args[j]) {
+            return false;
+          }
+        }
+      }
+      return true;
+    },
 
     guid: 0,
 
@@ -129,7 +149,7 @@ Handlebars.JavaScriptCompiler = function() {};
         // evaluate it by executing `blockHelperMissing`
         this.opcode('pushProgram', program);
         this.opcode('pushProgram', inverse);
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
         this.opcode('blockValue');
       } else {
         this.ambiguousMustache(mustache, program, inverse);
@@ -138,7 +158,7 @@ Handlebars.JavaScriptCompiler = function() {};
         // evaluate it by executing `blockHelperMissing`
         this.opcode('pushProgram', program);
         this.opcode('pushProgram', inverse);
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
         this.opcode('ambiguousBlockValue');
       }
 
@@ -162,6 +182,7 @@ Handlebars.JavaScriptCompiler = function() {};
 
         this.opcode('assignToHash', pair[0]);
       }
+      this.opcode('popHash');
     },
 
     partial: function(partial) {
@@ -202,14 +223,16 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     ambiguousMustache: function(mustache, program, inverse) {
-      var id = mustache.id, name = id.parts[0];
+      var id = mustache.id,
+          name = id.parts[0],
+          isBlock = program != null || inverse != null;
 
       this.opcode('getContext', id.depth);
 
       this.opcode('pushProgram', program);
       this.opcode('pushProgram', inverse);
 
-      this.opcode('invokeAmbiguous', name);
+      this.opcode('invokeAmbiguous', name, isBlock);
     },
 
     simpleMustache: function(mustache) {
@@ -343,7 +366,7 @@ Handlebars.JavaScriptCompiler = function() {};
       if(mustache.hash) {
         this.hash(mustache.hash);
       } else {
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
       }
 
       return params;
@@ -360,7 +383,7 @@ Handlebars.JavaScriptCompiler = function() {};
       if(mustache.hash) {
         this.hash(mustache.hash);
       } else {
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
       }
 
       return params;
@@ -389,7 +412,11 @@ Handlebars.JavaScriptCompiler = function() {};
       if (this.environment.isSimple) {
         return "return " + string + ";";
       } else {
-        return "buffer += " + string + ";";
+        return {
+          appendToBuffer: true,
+          content: string,
+          toString: function() { return "buffer += " + string + ";"; }
+        };
       }
     },
 
@@ -410,6 +437,7 @@ Handlebars.JavaScriptCompiler = function() {};
       this.isChild = !!context;
       this.context = context || {
         programs: [],
+        environments: [],
         aliases: { }
       };
 
@@ -419,6 +447,7 @@ Handlebars.JavaScriptCompiler = function() {};
       this.stackVars = [];
       this.registers = { list: [] };
       this.compileStack = [];
+      this.inlineStack = [];
 
       this.compileChildren(environment, options);
 
@@ -444,7 +473,7 @@ Handlebars.JavaScriptCompiler = function() {};
       return opcodes[this.i + 1];
     },
 
-    eat: function(opcode) {
+    eat: function() {
       this.i = this.i + 1;
     },
 
@@ -506,16 +535,42 @@ Handlebars.JavaScriptCompiler = function() {};
         params.push("depth" + this.environment.depths.list[i]);
       }
 
+      // Perform a second pass over the output to merge content when possible
+      var source = this.mergeSource();
+
       if (asObject) {
-        params.push(this.source.join("\n  "));
+        params.push(source);
 
         return Function.apply(this, params);
       } else {
-        var functionSource = 'function ' + (this.name || '') + '(' + params.join(',') + ') {\n  ' + this.source.join("\n  ") + '}';
+        var functionSource = 'function ' + (this.name || '') + '(' + params.join(',') + ') {\n  ' + source + '}';
         Handlebars.log(Handlebars.logger.DEBUG, functionSource + "\n\n");
         return functionSource;
       }
     },
+    mergeSource: function() {
+      // WARN: We are not handling the case where buffer is still populated as the source should
+      // not have buffer append operations as their final action.
+      var source = '',
+          buffer;
+      for (var i = 0, len = this.source.length; i < len; i++) {
+        var line = this.source[i];
+        if (line.appendToBuffer) {
+          if (buffer) {
+            buffer = buffer + '\n    + ' + line.content;
+          } else {
+            buffer = line.content;
+          }
+        } else {
+          if (buffer) {
+            source += 'buffer += ' + buffer + ';\n  ';
+            buffer = undefined;
+          }
+          source += line + '\n  ';
+        }
+      }
+      return source;
+    },
 
     // [blockValue]
     //
@@ -553,6 +608,9 @@ Handlebars.JavaScriptCompiler = function() {};
       var current = this.topStack();
       params.splice(1, 0, current);
 
+      // Use the options value generated from the invocation
+      params[params.length-1] = 'options';
+
       this.source.push("if (!" + this.lastHelper + ") { " + current + " = blockHelperMissing.call(" + params.join(", ") + "); }");
     },
 
@@ -576,6 +634,9 @@ Handlebars.JavaScriptCompiler = function() {};
     // If `value` is truthy, or 0, it is coerced into a string and appended
     // Otherwise, the empty string is appended
     append: function() {
+      // Force anything that is inlined onto the stack so we don't have duplication
+      // when we examine local
+      this.flushInline();
       var local = this.popStack();
       this.source.push("if(" + local + " || " + local + " === 0) { " + this.appendToBuffer(local) + " }");
       if (this.environment.isSimple) {
@@ -590,15 +651,9 @@ Handlebars.JavaScriptCompiler = function() {};
     //
     // Escape `value` and append it to the buffer
     appendEscaped: function() {
-      var opcode = this.nextOpcode(), extra = "";
       this.context.aliases.escapeExpression = 'this.escapeExpression';
 
-      if(opcode && opcode.opcode === 'appendContent') {
-        extra = " + " + this.quotedString(opcode.args[0]);
-        this.eat(opcode);
-      }
-
-      this.source.push(this.appendToBuffer("escapeExpression(" + this.popStack() + ")" + extra));
+      this.source.push(this.appendToBuffer("escapeExpression(" + this.popStack() + ")"));
     },
 
     // [getContext]
@@ -622,7 +677,7 @@ Handlebars.JavaScriptCompiler = function() {};
     // Looks up the value of `name` on the current context and pushes
     // it onto the stack.
     lookupOnContext: function(name) {
-      this.pushStack(this.nameLookup('depth' + this.lastContext, name, 'context'));
+      this.push(this.nameLookup('depth' + this.lastContext, name, 'context'));
     },
 
     // [pushContext]
@@ -670,7 +725,7 @@ Handlebars.JavaScriptCompiler = function() {};
     //
     // Push the result of looking up `id` on the current data
     lookupData: function(id) {
-      this.pushStack(this.nameLookup('data', id, 'data'));
+      this.push(this.nameLookup('data', id, 'data'));
     },
 
     // [pushStringParam]
@@ -693,13 +748,25 @@ Handlebars.JavaScriptCompiler = function() {};
       }
     },
 
-    pushHash: function() {
-      this.push('{}');
+    emptyHash: function() {
+      this.pushStackLiteral('{}');
 
       if (this.options.stringParams) {
         this.register('hashTypes', '{}');
       }
     },
+    pushHash: function() {
+      this.hash = {values: [], types: []};
+    },
+    popHash: function() {
+      var hash = this.hash;
+      this.hash = undefined;
+
+      if (this.options.stringParams) {
+        this.register('hashTypes', '{' + hash.types.join(',') + '}');
+      }
+      this.push('{\n    ' + hash.values.join(',\n    ') + '\n  }');
+    },
 
     // [pushString]
     //
@@ -718,7 +785,8 @@ Handlebars.JavaScriptCompiler = function() {};
     //
     // Push an expression onto the stack
     push: function(expr) {
-      this.pushStack(expr);
+      this.inlineStack.push(expr);
+      return expr;
     },
 
     // [pushLiteral]
@@ -761,12 +829,14 @@ Handlebars.JavaScriptCompiler = function() {};
     invokeHelper: function(paramSize, name) {
       this.context.aliases.helperMissing = 'helpers.helperMissing';
 
-      var helper = this.lastHelper = this.setupHelper(paramSize, name);
-      this.register('foundHelper', helper.name);
+      var helper = this.lastHelper = this.setupHelper(paramSize, name, true);
 
-      this.pushStack("foundHelper ? foundHelper.call(" +
-        helper.callParams + ") " + ": helperMissing.call(" +
-        helper.helperMissingParams + ")");
+      this.push(helper.name);
+      this.replaceStack(function(name) {
+        return name + ' ? ' + name + '.call(' +
+            helper.callParams + ") " + ": helperMissing.call(" +
+            helper.helperMissingParams + ")";
+      });
     },
 
     // [invokeKnownHelper]
@@ -778,7 +848,7 @@ Handlebars.JavaScriptCompiler = function() {};
     // so a `helperMissing` fallback is not required.
     invokeKnownHelper: function(paramSize, name) {
       var helper = this.setupHelper(paramSize, name);
-      this.pushStack(helper.name + ".call(" + helper.callParams + ")");
+      this.push(helper.name + ".call(" + helper.callParams + ")");
     },
 
     // [invokeAmbiguous]
@@ -793,19 +863,18 @@ Handlebars.JavaScriptCompiler = function() {};
     // This operation emits more code than the other options,
     // and can be avoided by passing the `knownHelpers` and
     // `knownHelpersOnly` flags at compile-time.
-    invokeAmbiguous: function(name) {
+    invokeAmbiguous: function(name, helperCall) {
       this.context.aliases.functionType = '"function"';
 
-      this.pushStackLiteral('{}');
-      var helper = this.setupHelper(0, name);
+      this.pushStackLiteral('{}');    // Hash value
+      var helper = this.setupHelper(0, name, helperCall);
 
       var helperName = this.lastHelper = this.nameLookup('helpers', name, 'helper');
-      this.register('foundHelper', helperName);
 
       var nonHelper = this.nameLookup('depth' + this.lastContext, name, 'context');
       var nextStack = this.nextStack();
 
-      this.source.push('if (foundHelper) { ' + nextStack + ' = foundHelper.call(' + helper.callParams + '); }');
+      this.source.push('if (' + nextStack + ' = ' + helperName + ') { ' + nextStack + ' = ' + nextStack + '.call(' + helper.callParams + '); }');
       this.source.push('else { ' + nextStack + ' = ' + nonHelper + '; ' + nextStack + ' = typeof ' + nextStack + ' === functionType ? ' + nextStack + '.apply(depth0) : ' + nextStack + '; }');
     },
 
@@ -824,7 +893,7 @@ Handlebars.JavaScriptCompiler = function() {};
       }
 
       this.context.aliases.self = "this";
-      this.pushStack("self.invokePartial(" + params.join(", ") + ")");
+      this.push("self.invokePartial(" + params.join(", ") + ")");
     },
 
     // [assignToHash]
@@ -835,17 +904,19 @@ Handlebars.JavaScriptCompiler = function() {};
     // Pops a value and hash off the stack, assigns `hash[key] = value`
     // and pushes the hash back onto the stack.
     assignToHash: function(key) {
-      var value = this.popStack();
+      var value = this.popStack(),
+          type;
 
       if (this.options.stringParams) {
-        var type = this.popStack();
+        type = this.popStack();
         this.popStack();
-        this.source.push("hashTypes['" + key + "'] = " + type + ";");
       }
 
-      var hash = this.topStack();
-
-      this.source.push(hash + "['" + key + "'] = " + value + ";");
+      var hash = this.hash;
+      if (type) {
+        hash.types.push("'" + key + "': " + type);
+      }
+      hash.values.push("'" + key + "': (" + value + ")");
     },
 
     // HELPERS
@@ -859,11 +930,27 @@ Handlebars.JavaScriptCompiler = function() {};
         child = children[i];
         compiler = new this.compiler();
 
-        this.context.programs.push('');     // Placeholder to prevent name conflicts for nested children
-        var index = this.context.programs.length;
-        child.index = index;
-        child.name = 'program' + index;
-        this.context.programs[index] = compiler.compile(child, options, this.context);
+        var index = this.matchExistingProgram(child);
+
+        if (index == null) {
+          this.context.programs.push('');     // Placeholder to prevent name conflicts for nested children
+          index = this.context.programs.length;
+          child.index = index;
+          child.name = 'program' + index;
+          this.context.programs[index] = compiler.compile(child, options, this.context);
+          this.context.environments[index] = child;
+        } else {
+          child.index = index;
+          child.name = 'program' + index;
+        }
+      }
+    },
+    matchExistingProgram: function(child) {
+      for (var i = 0, len = this.context.environments.length; i < len; i++) {
+        var environment = this.context.environments[i];
+        if (environment && environment.equals(child)) {
+          return i;
+        }
       }
     },
 
@@ -907,57 +994,111 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     pushStackLiteral: function(item) {
-      this.compileStack.push(new Literal(item));
-      return item;
+      return this.push(new Literal(item));
     },
 
     pushStack: function(item) {
+      this.flushInline();
+
       var stack = this.incrStack();
-      this.source.push(stack + " = " + item + ";");
+      if (item) {
+        this.source.push(stack + " = " + item + ";");
+      }
       this.compileStack.push(stack);
       return stack;
     },
 
     replaceStack: function(callback) {
-      var stack = this.topStack(),
-          item = callback.call(this, stack);
+      var prefix = '',
+          inline = this.isInline(),
+          stack;
+
+      // If we are currently inline then we want to merge the inline statement into the
+      // replacement statement via ','
+      if (inline) {
+        var top = this.popStack(true);
+
+        if (top instanceof Literal) {
+          // Literals do not need to be inlined
+          stack = top.value;
+        } else {
+          // Get or create the current stack name for use by the inline
+          var name = this.stackSlot ? this.topStackName() : this.incrStack();
 
-      // Prevent modification of the context depth variable. Through replaceStack
-      if (/^depth/.test(stack)) {
-        stack = this.nextStack();
+          prefix = '(' + this.push(name) + ' = ' + top + '),';
+          stack = this.topStack();
+        }
+      } else {
+        stack = this.topStack();
       }
 
-      this.source.push(stack + " = " + item + ";");
+      var item = callback.call(this, stack);
+
+      if (inline) {
+        if (this.inlineStack.length || this.compileStack.length) {
+          this.popStack();
+        }
+        this.push('(' + prefix + item + ')');
+      } else {
+        // Prevent modification of the context depth variable. Through replaceStack
+        if (!/^stack/.test(stack)) {
+          stack = this.nextStack();
+        }
+
+        this.source.push(stack + " = (" + prefix + item + ");");
+      }
       return stack;
     },
 
-    nextStack: function(skipCompileStack) {
-      var name = this.incrStack();
-      this.compileStack.push(name);
-      return name;
+    nextStack: function() {
+      return this.pushStack();
     },
 
     incrStack: function() {
       this.stackSlot++;
       if(this.stackSlot > this.stackVars.length) { this.stackVars.push("stack" + this.stackSlot); }
+      return this.topStackName();
+    },
+    topStackName: function() {
       return "stack" + this.stackSlot;
     },
+    flushInline: function() {
+      var inlineStack = this.inlineStack;
+      if (inlineStack.length) {
+        this.inlineStack = [];
+        for (var i = 0, len = inlineStack.length; i < len; i++) {
+          var entry = inlineStack[i];
+          if (entry instanceof Literal) {
+            this.compileStack.push(entry);
+          } else {
+            this.pushStack(entry);
+          }
+        }
+      }
+    },
+    isInline: function() {
+      return this.inlineStack.length;
+    },
 
-    popStack: function() {
-      var item = this.compileStack.pop();
+    popStack: function(wrapped) {
+      var inline = this.isInline(),
+          item = (inline ? this.inlineStack : this.compileStack).pop();
 
-      if (item instanceof Literal) {
+      if (!wrapped && (item instanceof Literal)) {
         return item.value;
       } else {
-        this.stackSlot--;
+        if (!inline) {
+          this.stackSlot--;
+        }
         return item;
       }
     },
 
-    topStack: function() {
-      var item = this.compileStack[this.compileStack.length - 1];
+    topStack: function(wrapped) {
+      var stack = (this.isInline() ? this.inlineStack : this.compileStack),
+          item = stack[stack.length - 1];
 
-      if (item instanceof Literal) {
+      if (!wrapped && (item instanceof Literal)) {
         return item.value;
       } else {
         return item;
@@ -972,22 +1113,22 @@ Handlebars.JavaScriptCompiler = function() {};
         .replace(/\r/g, '\\r') + '"';
     },
 
-    setupHelper: function(paramSize, name) {
+    setupHelper: function(paramSize, name, missingParams) {
       var params = [];
-      this.setupParams(paramSize, params);
+      this.setupParams(paramSize, params, missingParams);
       var foundHelper = this.nameLookup('helpers', name, 'helper');
 
       return {
         params: params,
         name: foundHelper,
         callParams: ["depth0"].concat(params).join(", "),
-        helperMissingParams: ["depth0", this.quotedString(name)].concat(params).join(", ")
+        helperMissingParams: missingParams && ["depth0", this.quotedString(name)].concat(params).join(", ")
       };
     },
 
     // the params and contexts arguments are passed in arrays
     // to fill in
-    setupParams: function(paramSize, params) {
+    setupParams: function(paramSize, params, useRegister) {
       var options = [], contexts = [], types = [], param, inverse, program;
 
       options.push("hash:" + this.popStack());
@@ -1032,7 +1173,13 @@ Handlebars.JavaScriptCompiler = function() {};
         options.push("data:data");
       }
 
-      params.push("{" + options.join(",") + "}");
+      options = "{" + options.join(",") + "}";
+      if (useRegister) {
+        this.register('options', options);
+        params.push('options');
+      } else {
+        params.push(options);
+      }
       return params.join(", ");
     }
   };