Adopting coco-style efficient bound functions for the common case ... but not for class/prototypes.

lib/coffee-script/nodes.js

@@ -1,6 +1,6 @@
 (function() {
   var Access, Arr, Assign, Base, Block, Call, Class, Closure, Code, Comment, Existence, Extends, For, IDENTIFIER, IDENTIFIER_STR, IS_STRING, If, In, Index, LEVEL_ACCESS, LEVEL_COND, LEVEL_LIST, LEVEL_OP, LEVEL_PAREN, LEVEL_TOP, Literal, METHOD_DEF, NEGATE, NO, Obj, Op, Param, Parens, RESERVED, Range, Return, SIMPLENUM, Scope, Slice, Splat, Switch, TAB, THIS, Throw, Try, UTILITIES, Value, While, YES, compact, del, ends, extend, flatten, last, merge, multident, starts, unfoldSoak, utility, _ref;
-  var __hasProp = Object.prototype.hasOwnProperty, __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor; child.__super__ = parent.prototype; return child; }, __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; }, __indexOf = Array.prototype.indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (__hasProp.call(this, i) && this[i] === item) return i; } return -1; };
+  var __hasProp = Object.prototype.hasOwnProperty, __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor; child.__super__ = parent.prototype; return child; }, __indexOf = Array.prototype.indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (__hasProp.call(this, i) && this[i] === item) return i; } return -1; };
 
   Scope = require('./scope').Scope;
 
@@ -397,8 +397,8 @@
     };
 
     Literal.prototype.compileNode = function(o) {
-      var code, _ref2;
+      var code, _ref2, _ref3;
-      code = this.isUndefined ? o.level >= LEVEL_ACCESS ? '(void 0)' : 'void 0' : this.value.reserved && ((_ref2 = "" + this.value) !== 'eval' && _ref2 !== 'arguments') ? "\"" + this.value + "\"" : this.value;
+      code = this.isUndefined ? o.level >= LEVEL_ACCESS ? '(void 0)' : 'void 0' : this.value === 'this' ? ((_ref2 = o.scope.method) != null ? _ref2.bound : void 0) ? o.scope.method.context : this.value : this.value.reserved && ((_ref3 = "" + this.value) !== 'eval' && _ref3 !== 'arguments') ? "\"" + this.value + "\"" : this.value;
       if (this.isStatement()) {
         return "" + this.tab + code + ";";
       } else {
@@ -563,20 +563,21 @@
 
     Value.prototype.unfoldSoak = function(o) {
       var result;
+      var _this = this;
       if (this.unfoldedSoak != null) return this.unfoldedSoak;
-      result = __bind(function() {
+      result = (function() {
         var fst, i, ifn, prop, ref, snd, _len, _ref2;
-        if (ifn = this.base.unfoldSoak(o)) {
+        if (ifn = _this.base.unfoldSoak(o)) {
-          Array.prototype.push.apply(ifn.body.properties, this.properties);
+          Array.prototype.push.apply(ifn.body.properties, _this.properties);
           return ifn;
         }
-        _ref2 = this.properties;
+        _ref2 = _this.properties;
         for (i = 0, _len = _ref2.length; i < _len; i++) {
           prop = _ref2[i];
           if (!prop.soak) continue;
           prop.soak = false;
-          fst = new Value(this.base, this.properties.slice(0, i));
+          fst = new Value(_this.base, _this.properties.slice(0, i));
-          snd = new Value(this.base, this.properties.slice(i));
+          snd = new Value(_this.base, _this.properties.slice(i));
           if (fst.isComplex()) {
             ref = new Literal(o.scope.freeVariable('ref'));
             fst = new Parens(new Assign(ref, fst));
@@ -587,7 +588,7 @@
           });
         }
         return null;
-      }, this)();
+      })();
       return this.unfoldedSoak = result || false;
     };
 
@@ -1166,7 +1167,8 @@
     };
 
     Class.prototype.walkBody = function(name, o) {
-      return this.traverseChildren(false, __bind(function(child) {
+      var _this = this;
+      return this.traverseChildren(false, function(child) {
         var exps, i, node, _len, _ref2;
         if (child instanceof Class) return false;
         if (child instanceof Block) {
@@ -1174,12 +1176,12 @@
           for (i = 0, _len = _ref2.length; i < _len; i++) {
             node = _ref2[i];
             if (node instanceof Value && node.isObject(true)) {
-              exps[i] = this.addProperties(node, name, o);
+              exps[i] = _this.addProperties(node, name, o);
             }
           }
           return child.expressions = exps = flatten(exps);
         }
-      }, this));
+      });
     };
 
     Class.prototype.ensureConstructor = function(name) {
@@ -1429,7 +1431,7 @@
       this.params = params || [];
       this.body = body || new Block;
       this.bound = tag === 'boundfunc';
-      if (this.bound) this.context = 'this';
+      if (this.bound) this.context = '_this';
     }
 
     Code.prototype.children = ['params', 'body'];
@@ -1441,7 +1443,7 @@
     Code.prototype.jumps = NO;
 
     Code.prototype.compileNode = function(o) {
-      var code, exprs, i, idt, lit, p, param, ref, splats, v, val, vars, wasEmpty, _i, _j, _k, _len, _len2, _len3, _len4, _ref2, _ref3, _ref4, _ref5;
+      var code, exprs, i, idt, lit, p, param, ref, splats, v, val, vars, wasEmpty, _i, _j, _k, _len, _len2, _len3, _len4, _ref2, _ref3, _ref4, _ref5, _ref6;
       o.scope = new Scope(o.scope, this.body, this);
       o.scope.shared = del(o, 'sharedScope');
       o.indent += TAB;
@@ -1500,6 +1502,13 @@
         }
       }
       if (!(wasEmpty || this.noReturn)) this.body.makeReturn();
+      if (this.bound) {
+        if ((_ref6 = o.scope.parent.method) != null ? _ref6.bound : void 0) {
+          this.bound = o.scope.parent.method.context;
+        } else {
+          o.scope.parent.assign('_this', 'this');
+        }
+      }
       idt = o.indent;
       code = 'function';
       if (this.ctor) code += ' ' + this.name;
@@ -1509,9 +1518,6 @@
       }
       code += '}';
       if (this.ctor) return this.tab + code;
-      if (this.bound) {
-        return utility('bind') + ("(" + code + ", " + this.context + ")");
-      }
       if (this.front || (o.level >= LEVEL_ACCESS)) {
         return "(" + code + ")";
       } else {

src/nodes.coffee

@@ -310,6 +310,8 @@ exports.Literal = class Literal extends Base
   compileNode: (o) ->
     code = if @isUndefined
       if o.level >= LEVEL_ACCESS then '(void 0)' else 'void 0'
+    else if @value is 'this'
+      if o.scope.method?.bound then o.scope.method.context else @value
     else if @value.reserved and "#{@value}" not in ['eval', 'arguments']
       "\"#{@value}\""
     else
@@ -1080,7 +1082,7 @@ exports.Code = class Code extends Base
     @params  = params or []
     @body    = body or new Block
     @bound   = tag is 'boundfunc'
-    @context = 'this' if @bound
+    @context = '_this' if @bound
 
   children: ['params', 'body']
 
@@ -1095,7 +1097,7 @@ exports.Code = class Code extends Base
   # a closure.
   compileNode: (o) ->
     o.scope         = new Scope o.scope, @body, this
-    o.scope.shared  = del o, 'sharedScope'
+    o.scope.shared  = del(o, 'sharedScope')
     o.indent        += TAB
     delete o.bare
     vars   = []
@@ -1122,6 +1124,11 @@ exports.Code = class Code extends Base
     @body.expressions.unshift exprs... if exprs.length
     o.scope.parameter vars[i] = v.compile o for v, i in vars unless splats
     @body.makeReturn() unless wasEmpty or @noReturn
+    if @bound
+      if o.scope.parent.method?.bound
+        @bound = o.scope.parent.method.context
+      else
+        o.scope.parent.assign '_this', 'this'
     idt   = o.indent
     code  = 'function'
     code  += ' ' + @name if @ctor
@@ -1129,7 +1136,6 @@ exports.Code = class Code extends Base
     code  += "\n#{ @body.compileWithDeclarations o }\n#{@tab}" unless @body.isEmpty()
     code  += '}'
     return @tab + code if @ctor
-    return utility('bind') + "(#{code}, #{@context})" if @bound
     if @front or (o.level >= LEVEL_ACCESS) then "(#{code})" else code
 
   # Short-circuit `traverseChildren` method to prevent it from crossing scope boundaries

test/functions.coffee

@@ -64,6 +64,21 @@ ok obj isnt obj.unbound()
 eq obj, obj.nested()
 
 
+test "even more fancy bound functions", ->
+  obj = 
+    one: ->
+      do =>
+        return this.two()
+    two: ->
+      do =>
+        do =>
+          do =>
+            return this.three
+    three: 3
+
+  eq obj.one(), 3
+
+
 test "self-referencing functions", ->
   changeMe = ->
     changeMe = 2