Clean up the compiler a bit

1 files changed, 91 insertions, 69 deletions

diff --git a/lib/handlebars/compiler/compiler.js b/lib/handlebars/compiler/compiler.js
index 8fccc90..994192b 100644
--- a/lib/handlebars/compiler/compiler.js
+++ b/lib/handlebars/compiler/compiler.js
@@ -22,15 +22,18 @@ Handlebars.JavaScriptCompiler = function() {};
     invokePartial: 12,
     push: 13,
     assignToHash: 15,
-    pushStringParam: 16
+    pushStringParam: 16,
+    knownHelper: 17,
+    pushContext: 18,
+    lookupOnContext: 19
   };
 
   Compiler.MULTI_PARAM_OPCODES = {
     appendContent: 1,
     getContext: 1,
-    lookupWithHelpers: 2,
+    lookupWithHelpers: 1,
     lookup: 1,
-    invokeMustache: 3,
+    invokeMustache: 2,
     pushString: 1,
     truthyOrFallback: 1,
     functionOrFallback: 1,
@@ -38,7 +41,10 @@ Handlebars.JavaScriptCompiler = function() {};
     invokePartial: 1,
     push: 1,
     assignToHash: 1,
-    pushStringParam: 1
+    pushStringParam: 1,
+    knownHelper: 1,
+    pushContext: 0,
+    lookupOnContext: 1
   };
 
   Compiler.DISASSEMBLE_MAP = {};
@@ -227,7 +233,7 @@ Handlebars.JavaScriptCompiler = function() {};
     mustache: function(mustache) {
       var params = this.setupStackForMustache(mustache);
 
-      this.opcode('invokeMustache', params.length, mustache.id.original, !!mustache.hash);
+      this.opcode('invokeMustache', params.length, mustache.id.original);
 
       if(mustache.escaped && !this.options.noEscape) {
         this.opcode('appendEscaped');
@@ -241,7 +247,20 @@ Handlebars.JavaScriptCompiler = function() {};
 
       this.opcode('getContext', id.depth);
 
-      this.opcode('lookupWithHelpers', id.parts[0] || null, id.isScoped || false);
+      var name = id.parts[0];
+
+      if (!name) {
+        this.opcode('pushContext');
+      } else if (!id.isScoped && this.options.knownHelpers[name]) {
+        this.declare('usingKnownHelper', true);
+        this.opcode('knownHelper', name);
+      } else if (id.isScoped || this.options.knownHelpersOnly) {
+        this.declare('usingKnownHelper', false);
+        this.opcode('lookupOnContext', name);
+      } else {
+        this.declare('usingKnownHelper', false);
+        this.opcode('lookupWithHelpers', name);
+      }
 
       for(var i=1, l=id.parts.length; i<l; i++) {
         this.opcode('lookup', id.parts[i]);
@@ -311,6 +330,8 @@ Handlebars.JavaScriptCompiler = function() {};
 
       if(mustache.hash) {
         this.hash(mustache.hash);
+      } else {
+        this.opcode('push', '{}');
       }
 
       this.ID(mustache.id);
@@ -521,23 +542,21 @@ Handlebars.JavaScriptCompiler = function() {};
       }
     },
 
-    lookupWithHelpers: function(name, isScoped) {
-      if(name) {
-        this.usingKnownHelper = false;
+    knownHelper: function(name) {
+      this.pushStackLiteral(this.nameLookup('helpers', name, 'helper'));
+    },
 
-        var toPush;
-        if (!isScoped && this.options.knownHelpers[name]) {
-          this.usingKnownHelper = true;
-          this.pushStackLiteral(this.nameLookup('helpers', name, 'helper'));
-        } else if (isScoped || this.options.knownHelpersOnly) {
-          this.pushStackLiteral(this.nameLookup('depth' + this.lastContext, name, 'context'));
-        } else {
-          this.register('foundHelper', this.nameLookup('helpers', name, 'helper'));
-          this.pushStack("foundHelper || " + this.nameLookup('depth' + this.lastContext, name, 'context'));
-        }
-      } else {
-        this.pushStackLiteral('depth' + this.lastContext);
-      }
+    lookupOnContext: function(name) {
+      this.pushStackLiteral(this.nameLookup('depth' + this.lastContext, name, 'context'));
+    },
+
+    pushContext: function() {
+      this.pushStackLiteral('depth' + this.lastContext);
+    },
+
+    lookupWithHelpers: function(name) {
+      this.register('foundHelper', this.nameLookup('helpers', name, 'helper'));
+      this.pushStack("foundHelper || " + this.nameLookup('depth' + this.lastContext, name, 'context'));
     },
 
     lookup: function(name) {
@@ -559,43 +578,52 @@ Handlebars.JavaScriptCompiler = function() {};
       this.pushStack(name);
     },
 
-    invokeMustache: function(paramSize, original, hasHash) {
-      this.populateParams(paramSize, this.quotedString(original), null, null, hasHash, function(nextStack, helperMissingString, id) {
-        if (!this.usingKnownHelper) {
-          this.context.aliases.helperMissing = 'helpers.helperMissing';
-          this.context.aliases.undef = 'void 0';
-          this.source.push("else if(" + id + "=== undef) { " + nextStack + " = helperMissing.call(" + helperMissingString + "); }");
-          if (nextStack !== id) {
-            this.source.push("else { " + nextStack + " = " + id + "; }");
-          }
+    // The rules for mustaches are:
+    //
+    // If the first parameter resolves to a function, call the function with the remaining parameters
+    // If the first parameter resolves to undefined, call helperMissing with the string form of the
+    //   first parameter and the remaining parameters
+    // Otherwise, if there is only one parameter, the expression evaluates to the value of the first
+    //   parameter
+    invokeMustache: function(paramSize, original) {
+      this.populateParams(paramSize, this.quotedString(original), [], true, function(nextStack, helperMissingString, id) {
+        this.context.aliases.helperMissing = 'helpers.helperMissing';
+        this.context.aliases.undef = 'void 0';
+
+        this.source.push("else if(" + id + "=== undef) { " + nextStack + " = helperMissing.call(" + helperMissingString + "); }");
+        if (nextStack !== id) {
+          this.source.push("else { " + nextStack + " = " + id + "; }");
         }
       });
     },
 
-    invokeProgram: function(guid, paramSize, hasHash) {
-      var inverse = this.programExpression(this.inverse);
-      var mainProgram = this.programExpression(guid);
+    // The rules for mustaches containing a block are:
+    //
+    // If the first parameter resolves to a function, call the function with the remaining parameters
+    // Otherwise, invoke blockHelperMissing with the string form of the first parameter and the
+    //   remaining parameters.
+    invokeProgram: function(guid, paramSize) {
+      var options = [], program, inverse;
 
-      this.populateParams(paramSize, null, mainProgram, inverse, hasHash, function(nextStack, helperMissingString, id) {
-        if (!this.usingKnownHelper) {
-          this.context.aliases.blockHelperMissing = 'helpers.blockHelperMissing';
-          this.source.push("else { " + nextStack + " = blockHelperMissing.call(" + helperMissingString + "); }");
-        }
+      if (inverse = this.programExpression(this.inverse)) {
+        options.push("inverse:" + inverse);
+      }
+
+      if (program = this.programExpression(guid)) {
+        options.push("fn:" + program);
+      }
+
+      this.populateParams(paramSize, null, options, false, function(nextStack, helperMissingString) {
+        this.context.aliases.blockHelperMissing = 'helpers.blockHelperMissing';
+        this.source.push("else { " + nextStack + " = blockHelperMissing.call(" + helperMissingString + "); }");
       });
     },
 
-    populateParams: function(paramSize, helperId, program, inverse, hasHash, callback) {
-      var needsRegister = hasHash || this.options.stringParams || inverse || this.options.data;
+    populateParams: function(paramSize, helperId, options, resolveLambdas, callback) {
       var id = this.popStack(), nextStack;
-      var params = [], param, stringParam, stringOptions;
-
-      var options = [], contexts = [];
+      var params = [], contexts = [], param, paramString, stringOptions;
 
-      if (hasHash) {
-        options.push("hash:" + this.popStack());
-      } else {
-        options.push("hash:{}");
-      }
+      options.push("hash:" + this.popStack());
 
       for(var i=0; i<paramSize; i++) {
         param = this.popStack();
@@ -610,14 +638,6 @@ Handlebars.JavaScriptCompiler = function() {};
         options.push("contexts:[" + contexts.join(",") + "]");
       }
 
-      if (program) {
-        options.push("fn:" + program);
-      }
-
-      if (inverse) {
-        options.push("inverse:" + inverse);
-      }
-
       if(this.options.data) {
         options.push("data:data");
       }
@@ -626,25 +646,27 @@ Handlebars.JavaScriptCompiler = function() {};
 
       params.push("params");
 
-      this.populateCall(params, id, helperId || id, callback, program);
+      if (this.usingKnownHelper) {
+        this.pushStack(id + ".call(" + ["depth0"].concat(params).join(", ") + ")");
+      } else {
+        this.findAndCallHelper(params, id, helperId || id, resolveLambdas, callback);
+      }
     },
 
-    populateCall: function(params, id, helperId, callback, program) {
+    findAndCallHelper: function(params, id, helperId, resolveLambdas, callback) {
+      this.useRegister('foundHelper');
+      this.context.aliases.functionType = '"function"';
+
       var paramString = ["depth0"].concat(params).join(", "), nextStack;
       var helperMissingString = ["depth0"].concat(helperId).concat(params).join(", ");
 
-      if (this.usingKnownHelper) {
-        nextStack = this.pushStack(id + ".call(" + paramString + ")");
-      } else {
-        this.useRegister('foundHelper');
+      nextStack = this.nextStack();
+      var condition = resolveLambdas ? "" : "foundHelper && ";
+
+      this.source.push("if(" + condition + "typeof " + id + " === functionType) { " +
+        nextStack + " = " + id + ".call(" + paramString + "); }");
 
-        nextStack = this.nextStack();
-        this.context.aliases.functionType = '"function"';
-        var condition = program ? "foundHelper && " : "";
-        this.source.push("if(" + condition + "typeof " + id + " === functionType) { " + nextStack + " = " + id + ".call(" + paramString + "); }");
-      }
       callback.call(this, nextStack, helperMissingString, id);
-      this.usingKnownHelper = false;
     },
 
     invokePartial: function(context) {