nodes: refactored and removed the notion of o.top in favor of LVL_TOP

2026-02-18 03:21:20 -05:00 · 2010-10-23 18:06:04 +09:00
parent b82f495ec7
commit 2bc2c4717e
7 changed files with 365 additions and 431 deletions
--- a/lib/nodes.js
+++ b/lib/nodes.js
@@ -1,5 +1,5 @@
 (function() {
-  var Accessor, ArrayLiteral, Assign, Base, Call, Class, Closure, Code, Comment, Existence, Expressions, Extends, For, IDENTIFIER, IS_STRING, If, In, Index, LVL_ACCESS, LVL_ASSIGN, LVL_COND, LVL_LIST, LVL_OP, LVL_PAREN, LVL_TOP, Literal, NO, NUMBER, ObjectLiteral, Op, Param, Parens, Push, Return, SIMPLENUM, Scope, Splat, Switch, TAB, THIS, TRAILING_WHITESPACE, Throw, Try, UTILITIES, Value, While, YES, _ref, compact, del, ends, extend, flatten, last, merge, starts, utility;
+  var Accessor, ArrayLiteral, Assign, Base, Call, Class, Closure, Code, Comment, Existence, Expressions, Extends, For, IDENTIFIER, IS_STRING, If, In, Index, LVL_ACCESS, LVL_COND, LVL_LIST, LVL_OP, LVL_PAREN, LVL_TOP, Literal, NO, NUMBER, ObjectLiteral, Op, Param, Parens, Push, Return, SIMPLENUM, Scope, Splat, Switch, TAB, THIS, TRAILING_WHITESPACE, Throw, Try, UTILITIES, Value, While, YES, _ref, compact, del, ends, extend, flatten, last, merge, multident, starts, utility;
  var __extends = function(child, parent) {
    function ctor() { this.constructor = child; }
    ctor.prototype = parent.prototype;
@@ -31,14 +31,14 @@
      return Base;
    })();
    Base.prototype.compile = function(o, lvl) {
-      var top;
+      var node;
      o = o ? extend({}, o) : {};
-      if (lvl) {
+      if (lvl != null) {
        o.level = lvl;
      }
-      top = this.topSensitive ? o.top : del(o, 'top');
-      this.tab = o.indent;
-      return top || o.asStatement || this instanceof Comment || this.isPureStatement() || !this.isStatement(o) ? this.compileNode(o) : this.compileClosure(o);
+      node = this.unfoldSoak(o) || this;
+      node.tab = o.indent;
+      return o.level === LVL_TOP || node.isPureStatement() || !node.isStatement(o) ? node.compileNode(o) : node.compileClosure(o);
    };
    Base.prototype.compileClosure = function(o) {
      if (this.containsPureStatement()) {
@@ -60,7 +60,7 @@
    };
    Base.prototype.compileLoopReference = function(o, name) {
      var src, tmp;
-      src = tmp = this.compile(o, LVL_ASSIGN);
+      src = tmp = this.compile(o, LVL_LIST);
      if (!(NUMBER.test(src) || IDENTIFIER.test(src) && o.scope.check(src, {
        immediate: true
      }))) {
@@ -98,7 +98,7 @@
    Base.prototype.toString = function(idt, override) {
      var _i, _len, _ref2, _result, child, children, klass;
      idt || (idt = '');
-      children = (function() {
+      children = ((function() {
        _ref2 = this.collectChildren();
        _result = [];
        for (_i = 0, _len = _ref2.length; _i < _len; _i++) {
@@ -106,7 +106,7 @@
          _result.push(child.toString(idt + TAB));
        }
        return _result;
-      }).call(this).join('');
+      }).call(this)).join('');
      klass = override || this.constructor.name + (this.soakNode ? '?' : '');
      return '\n' + idt + klass + children;
    };
@@ -155,7 +155,6 @@
    Base.prototype.isPureStatement = NO;
    Base.prototype.isComplex = YES;
    Base.prototype.isChainable = NO;
-    Base.prototype.topSensitive = false;
    Base.prototype.unfoldSoak = NO;
    Base.prototype.assigns = NO;
    return Base;
@@ -204,15 +203,16 @@
    };
    Expressions.prototype.compileNode = function(o) {
      var _i, _len, _ref2, _result, node;
-      return (function() {
+      this.tab = o.indent;
+      return ((function() {
        _ref2 = this.expressions;
        _result = [];
        for (_i = 0, _len = _ref2.length; _i < _len; _i++) {
          node = _ref2[_i];
-          _result.push(this.compileExpression(node, merge(o)));
+          _result.push(this.compileExpression(node, o));
        }
        return _result;
-      }).call(this).join('\n');
+      }).call(this)).join('\n');
    };
    Expressions.prototype.compileRoot = function(o) {
      var code;
@@ -224,20 +224,25 @@
      return o.bare ? code : "(function() {\n" + code + "\n}).call(this);\n";
    };
    Expressions.prototype.compileWithDeclarations = function(o) {
-      var code;
+      var code, scope;
      code = this.compileNode(o);
-      if (o.scope.hasAssignments(this)) {
-        code = "" + this.tab + "var " + (o.scope.compiledAssignments().replace(/\n/g, '$&' + this.tab)) + ";\n" + code;
+      scope = o.scope;
+      if (scope.hasAssignments(this)) {
+        code = "" + this.tab + "var " + (multident(scope.compiledAssignments(), this.tab)) + ";\n" + code;
      }
      if (!o.globals && o.scope.hasDeclarations(this)) {
-        code = "" + this.tab + "var " + (o.scope.compiledDeclarations()) + ";\n" + code;
+        code = "" + this.tab + "var " + (scope.compiledDeclarations()) + ";\n" + code;
      }
      return code;
    };
    Expressions.prototype.compileExpression = function(node, o) {
      var code;
-      o.top = node.tags.front = true;
-      this.tab = o.indent;
+      while (node !== (node = node.unwrap())) {
+
+      }
+      node = node.unfoldSoak(o) || node;
+      node.tags.front = true;
+      o.level = LVL_TOP;
      code = node.compile(o);
      return node.isStatement(o) ? code : this.tab + code + ';';
    };
@@ -262,19 +267,16 @@
    Literal.prototype.makeReturn = function() {
      return this.isStatement() ? this : Literal.__super__.makeReturn.call(this);
    };
-    Literal.prototype.isStatement = function() {
+    Literal.prototype.isPureStatement = function() {
      var _ref2;
      return (_ref2 = this.value) === 'break' || _ref2 === 'continue' || _ref2 === 'debugger';
    };
-    Literal.prototype.isPureStatement = Literal.prototype.isStatement;
    Literal.prototype.isComplex = NO;
    Literal.prototype.assigns = function(name) {
      return name === this.value;
    };
-    Literal.prototype.compileNode = function() {
-      var val;
-      val = this.value.reserved ? "\"" + this.value + "\"" : this.value;
-      return this.isStatement() ? this.tab + val + ';' : val;
+    Literal.prototype.compile = function() {
+      return this.value.reserved ? "\"" + this.value + "\"" : this.value;
    };
    Literal.prototype.toString = function() {
      return ' "' + this.value + '"';
@@ -301,15 +303,8 @@
      return expr && !(expr instanceof Return) ? expr.compile(o, lvl) : Return.__super__.compile.call(this, o, lvl);
    };
    Return.prototype.compileNode = function(o) {
-      var expr;
-      expr = '';
-      if (this.expression) {
-        if (this.expression.isStatement(o)) {
-          o.asStatement = true;
-        }
-        expr = ' ' + this.expression.compile(o, LVL_PAREN);
-      }
-      return this.tab + 'return' + expr + ';';
+      o.level = LVL_PAREN;
+      return this.tab + ("return" + (this.expression ? ' ' + this.expression.compile(o) : '') + ";");
    };
    return Return;
  })();
@@ -365,7 +360,7 @@
      return this.properties.length ? this : this.base;
    };
    Value.prototype.isStatement = function(o) {
-      return this.base.isStatement(o) && !this.properties.length;
+      return !this.properties.length && this.base.isStatement(o);
    };
    Value.prototype.isSimpleNumber = function() {
      return this.base instanceof Literal && SIMPLENUM.test(this.base.value);
@@ -391,23 +386,17 @@
      }
      return [base.push(name), new Value(bref || base.base, [nref || name])];
    };
-    Value.prototype.compile = function(o, lvl) {
-      this.base.tags.front = this.tags.front;
-      return !o.top || this.properties.length ? Value.__super__.compile.call(this, o, lvl) : this.base.compile(o, lvl);
-    };
    Value.prototype.compileNode = function(o) {
-      var _i, _len, code, ifn, prop, props;
-      if (ifn = this.unfoldSoak(o)) {
-        return ifn.compile(o);
-      }
+      var _i, _len, code, prop, props;
+      this.base.tags.front = this.tags.front;
      props = this.properties;
-      code = this.base.compile(o, props.length && LVL_ACCESS);
+      code = this.base.compile(o, props.length ? LVL_ACCESS : null);
      if (props[0] instanceof Accessor && this.isSimpleNumber()) {
        code = "(" + code + ")";
      }
      for (_i = 0, _len = props.length; _i < _len; _i++) {
        prop = props[_i];
-        (code += prop.compileNode(o));
+        code += prop.compile(o);
      }
      return code;
    };
@@ -451,10 +440,10 @@
      return Comment;
    })();
    __extends(Comment, Base);
-    Comment.prototype.isStatement = YES;
+    Comment.prototype.isPureStatement = YES;
    Comment.prototype.makeReturn = THIS;
    Comment.prototype.compileNode = function(o) {
-      return this.tab + '/*' + this.comment.replace(/\n/g, '\n' + this.tab) + '*/';
+      return this.tab + '/*' + multident(this.comment, this.tab) + '*/';
    };
    return Comment;
  })();
@@ -543,11 +532,10 @@
      return ifn;
    };
    Call.prototype.compileNode = function(o) {
-      var _i, _j, _len, _len2, _ref2, _ref3, _ref4, _result, arg, args, ifn;
-      if (ifn = this.unfoldSoak(o)) {
-        return ifn.compile(o);
+      var _i, _j, _len, _len2, _ref2, _ref3, _ref4, _result, arg, args;
+      if ((_ref2 = this.variable) != null) {
+        _ref2.tags.front = this.tags.front;
      }
-      (_ref2 = this.variable) != null ? _ref2.tags.front = this.tags.front : undefined;
      _ref3 = this.args;
      for (_i = 0, _len = _ref3.length; _i < _len; _i++) {
        arg = _ref3[_i];
@@ -555,7 +543,7 @@
          return this.compileSplat(o);
        }
      }
-      args = (function() {
+      args = ((function() {
        _ref4 = this.args;
        _result = [];
        for (_j = 0, _len2 = _ref4.length; _j < _len2; _j++) {
@@ -563,7 +551,7 @@
          _result.push(arg.compile(o, LVL_LIST));
        }
        return _result;
-      }).call(this).join(', ');
+      }).call(this)).join(', ');
      return this.isSuper ? this.compileSuper(args, o) : (this.isNew ? 'new ' : '') + this.variable.compile(o, LVL_ACCESS) + ("(" + args + ")");
    };
    Call.prototype.compileSuper = function(args, o) {
@@ -579,11 +567,11 @@
        base = Value.wrap(this.variable);
        if ((name = base.properties.pop()) && base.isComplex()) {
          ref = o.scope.freeVariable('this');
-          fun = "(" + ref + " = " + (base.compile(o, LVL_ASSIGN)) + ")" + (name.compileNode(o));
+          fun = "(" + ref + " = " + (base.compile(o, LVL_LIST)) + ")" + (name.compile(o));
        } else {
          fun = ref = base.compile(o, LVL_ACCESS);
          if (name) {
-            fun += name.compileNode(o);
+            fun += name.compile(o);
          }
        }
        return "" + fun + ".apply(" + ref + ", " + splatargs + ")";
@@ -605,7 +593,7 @@
    })();
    __extends(Extends, Base);
    Extends.prototype.children = ['child', 'parent'];
-    Extends.prototype.compileNode = function(o) {
+    Extends.prototype.compile = function(o) {
      return new Call(new Value(new Literal(utility('extends'))), [this.child, this.parent]).compile(o);
    };
    return Extends;
@@ -623,7 +611,7 @@
    })();
    __extends(Accessor, Base);
    Accessor.prototype.children = ['name'];
-    Accessor.prototype.compileNode = function(o) {
+    Accessor.prototype.compile = function(o) {
      var name;
      name = this.name.compile(o);
      return this.proto + (IS_STRING.test(name) ? "[" + name + "]" : "." + name);
@@ -642,7 +630,7 @@
    })();
    __extends(Index, Base);
    Index.prototype.children = ['index'];
-    Index.prototype.compileNode = function(o) {
+    Index.prototype.compile = function(o) {
      return (this.proto ? '.prototype' : '') + ("[" + (this.index.compile(o, LVL_PAREN)) + "]");
    };
    Index.prototype.isComplex = function() {
@@ -662,8 +650,7 @@
    __extends(ObjectLiteral, Base);
    ObjectLiteral.prototype.children = ['properties'];
    ObjectLiteral.prototype.compileNode = function(o) {
-      var _i, _len, _ref2, _result, i, indent, join, lastNoncom, nonComments, obj, prop, props, top;
-      top = del(o, 'top');
+      var _i, _len, _ref2, _result, i, indent, join, lastNoncom, nonComments, obj, prop, props;
      o.indent = this.idt(1);
      nonComments = (function() {
        _ref2 = this.properties;
@@ -779,14 +766,13 @@
      return this;
    };
    Class.prototype.compileNode = function(o) {
-      var _i, _len, _ref2, _ref3, access, applied, apply, className, constScope, construct, constructor, extension, func, me, pname, prop, props, pvar, ref, returns, val, variable;
+      var _i, _len, _ref2, _ref3, access, applied, apply, className, constScope, construct, constructor, extension, func, me, pname, prop, props, pvar, ref, val, variable;
      variable = this.variable;
      if (variable.value === '__temp__') {
        variable = new Literal(o.scope.freeVariable('ctor'));
      }
      extension = this.parent && new Extends(variable, this.parent);
      props = new Expressions;
-      o.top = true;
      me = null;
      className = variable.compile(o);
      constScope = null;
@@ -847,13 +833,18 @@
      if (me) {
        constructor.body.unshift(new Literal("" + me + " = this"));
      }
-      construct = this.idt() + new Assign(variable, constructor).compile(merge(o, {
-        sharedScope: constScope
-      })) + ';';
-      props = !props.empty() ? '\n' + props.compile(o) : '';
-      extension = extension ? '\n' + this.idt() + extension.compile(o) + ';' : '';
-      returns = this.returns ? '\n' + new Return(variable).compile(o) : '';
-      return construct + extension + props + returns;
+      o.sharedScope = constScope;
+      construct = this.tab + new Assign(variable, constructor).compile(o) + ';';
+      if (extension) {
+        construct += '\n' + this.tab + extension.compile(o) + ';';
+      }
+      if (!props.empty()) {
+        construct += '\n' + props.compile(o);
+      }
+      if (this.returns) {
+        construct += '\n' + new Return(variable).compile(o);
+      }
+      return construct;
    };
    return Class;
  })();
@@ -872,29 +863,28 @@
    Assign.prototype.METHOD_DEF = /^(?:(\S+)\.prototype\.)?([$A-Za-z_][$\w]*)$/;
    Assign.prototype.CONDITIONAL = ['||=', '&&=', '?='];
    Assign.prototype.children = ['variable', 'value'];
-    Assign.prototype.topSensitive = true;
+    Assign.prototype.assigns = function(name) {
+      return this[this.context === 'object' ? 'value' : 'variable'].assigns(name);
+    };
+    Assign.prototype.unfoldSoak = function(o) {
+      return If.unfoldSoak(o, this, 'variable');
+    };
    Assign.prototype.compileNode = function(o) {
-      var _ref2, ifn, isValue, match, name, stmt, top, val;
+      var _ref2, isValue, match, name, val;
      if (isValue = this.variable instanceof Value) {
        if (this.variable.isArray() || this.variable.isObject()) {
          return this.compilePatternMatch(o);
        }
-        if (ifn = If.unfoldSoak(o, this, 'variable')) {
-          delete o.top;
-          return ifn.compile(o);
-        }
        if (_ref2 = this.context, __indexOf.call(this.CONDITIONAL, _ref2) >= 0) {
          return this.compileConditional(o);
        }
      }
-      top = del(o, 'top');
-      stmt = del(o, 'asStatement');
-      name = this.variable.compile(o, LVL_ASSIGN);
+      name = this.variable.compile(o, LVL_LIST);
      if (this.value instanceof Code && (match = this.METHOD_DEF.exec(name))) {
        this.value.name = match[2];
        this.value.klass = match[1];
      }
-      val = this.value.compile(o, LVL_ASSIGN);
+      val = this.value.compile(o, LVL_LIST);
      if (this.context === 'object') {
        return "" + name + ": " + val;
      }
@@ -902,17 +892,11 @@
        o.scope.find(name);
      }
      val = name + (" " + (this.context || '=') + " ") + val;
-      if (stmt) {
-        return "" + this.tab + val + ";";
-      }
-      return top || o.level <= LVL_ASSIGN ? val : "(" + val + ")";
+      return o.level <= LVL_LIST ? val : "(" + val + ")";
    };
    Assign.prototype.compilePatternMatch = function(o) {
-      var _len, _ref2, _ref3, accessClass, assigns, code, i, idx, isObject, obj, objects, olength, otop, ref, splat, top, val, valVar, value;
-      top = del(o, 'top');
-      otop = merge(o, {
-        top: true
-      });
+      var _len, _ref2, _ref3, _ref4, _ref5, accessClass, assigns, code, i, idx, isObject, obj, objects, olength, ref, splat, top, val, valVar, value;
+      top = o.level === LVL_TOP;
      value = this.value;
      objects = this.variable.base.objects;
      if (!(olength = objects.length)) {
@@ -921,15 +905,15 @@
      isObject = this.variable.isObject();
      if (top && olength === 1 && !((obj = objects[0]) instanceof Splat)) {
        if (obj instanceof Assign) {
-          _ref2 = obj, idx = _ref2.variable.base, obj = _ref2.value;
+          _ref2 = obj, (_ref3 = _ref2.variable, idx = _ref3.base, _ref3), obj = _ref2.value;
        } else {
          idx = isObject ? obj.tags["this"] ? obj.properties[0].name : obj : new Literal(0);
        }
        accessClass = IDENTIFIER.test(idx.value) ? Accessor : Index;
        (value = Value.wrap(value)).properties.push(new accessClass(idx));
-        return new Assign(obj, value).compile(otop);
+        return new Assign(obj, value).compile(o);
      }
-      valVar = value.compile(o);
+      valVar = value.compile(o, LVL_LIST);
      assigns = [];
      splat = false;
      if (!IDENTIFIER.test(valVar) || this.variable.assigns(valVar)) {
@@ -941,7 +925,7 @@
        idx = i;
        if (isObject) {
          if (obj instanceof Assign) {
-            _ref3 = obj, idx = _ref3.variable.base, obj = _ref3.value;
+            _ref4 = obj, (_ref5 = _ref4.variable, idx = _ref5.base, _ref5), obj = _ref4.value;
          } else {
            idx = obj.tags["this"] ? obj.properties[0].name : obj;
          }
@@ -959,22 +943,19 @@
          }
          val = new Value(new Literal(valVar), [new accessClass(idx)]);
        }
-        assigns.push(new Assign(obj, val).compile(otop));
+        assigns.push(new Assign(obj, val).compile(o, LVL_LIST));
      }
      if (!top) {
        assigns.push(valVar);
      }
      code = assigns.join(', ');
-      return top || o.level <= LVL_PAREN ? code : "(" + code + ")";
+      return o.level < LVL_LIST ? code : "(" + code + ")";
    };
    Assign.prototype.compileConditional = function(o) {
      var _ref2, left, rite;
      _ref2 = this.variable.cacheReference(o), left = _ref2[0], rite = _ref2[1];
      return new Op(this.context.slice(0, -1), left, new Assign(rite, this.value)).compile(o);
    };
-    Assign.prototype.assigns = function(name) {
-      return this[this.context === 'object' ? 'value' : 'variable'].assigns(name);
-    };
    return Assign;
  })();
  exports.Code = (function() {
@@ -996,11 +977,9 @@
    __extends(Code, Base);
    Code.prototype.children = ['params', 'body'];
    Code.prototype.compileNode = function(o) {
-      var _i, _len, _len2, _ref2, _ref3, _result, close, code, comm, empty, func, i, open, param, params, sharedScope, splat, top, value;
+      var _i, _len, _len2, _ref2, _ref3, _result, close, code, comm, empty, func, i, idt, open, param, params, scope, sharedScope, splat, value;
      sharedScope = del(o, 'sharedScope');
-      top = del(o, 'top');
-      o.scope = sharedScope || new Scope(o.scope, this.body, this);
-      o.top = true;
+      o.scope = scope = sharedScope || new Scope(o.scope, this.body, this);
      o.indent = this.idt(1);
      empty = this.body.expressions.length === 0;
      delete o.bare;
@@ -1019,7 +998,7 @@
        } else {
          if (param.attach) {
            value = param.value;
-            _ref3 = [new Literal(o.scope.freeVariable('arg')), param.splat], param = _ref3[0], param.splat = _ref3[1];
+            _ref3 = [new Literal(scope.freeVariable('arg')), param.splat], param = _ref3[0], param.splat = _ref3[1];
            this.body.unshift(new Assign(new Value(new Literal('this'), [new Accessor(value)]), param));
          }
          if (param.splat) {
@@ -1033,31 +1012,36 @@
          }
        }
      }
-      o.scope.startLevel();
+      scope.startLevel();
+      if (!(empty || this.noReturn)) {
+        this.body.makeReturn();
+      }
      params = (function() {
        _result = [];
        for (_i = 0, _len2 = params.length; _i < _len2; _i++) {
          param = params[_i];
-          _result.push(param.compile(o));
+          _result.push((function() {
+            scope.parameter(param = param.compile(o));
+            return param;
+          })());
        }
        return _result;
      })();
-      if (!(empty || this.noReturn)) {
-        this.body.makeReturn();
-      }
-      for (_i = 0, _len2 = params.length; _i < _len2; _i++) {
-        param = params[_i];
-        o.scope.parameter(param);
-      }
      comm = this.comment ? this.comment.compile(o) + '\n' : '';
      if (this.className) {
        o.indent = this.idt(2);
      }
+      idt = this.idt(1);
      code = this.body.expressions.length ? "\n" + (this.body.compileWithDeclarations(o)) + "\n" : '';
-      open = this.className ? "(function() {\n" + comm + (this.idt(1)) + "function " + this.className + "(" : "function(";
-      close = this.className ? "" + (code && this.idt(1)) + "};\n" + (this.idt(1)) + "return " + this.className + ";\n" + this.tab + "})()" : "" + (code && this.tab) + "}";
+      if (this.className) {
+        open = "(function() {\n" + comm + idt + "function " + this.className + "(";
+        close = "" + (code && idt) + "};\n" + idt + "return " + this.className + ";\n" + this.tab + "})()";
+      } else {
+        open = "function(";
+        close = "" + (code && this.tab) + "}";
+      }
      func = "" + open + (params.join(', ')) + ") {" + code + close;
-      o.scope.endLevel();
+      scope.endLevel();
      if (this.bound) {
        return "" + (utility('bind')) + "(" + func + ", " + this.context + ")";
      }
@@ -1082,7 +1066,7 @@
    })();
    __extends(Param, Base);
    Param.prototype.children = ['name'];
-    Param.prototype.compileNode = function(o) {
+    Param.prototype.compile = function(o) {
      return this.value.compile(o, LVL_LIST);
    };
    Param.prototype.toString = function() {
@@ -1112,7 +1096,7 @@
    Splat.prototype.assigns = function(name) {
      return this.name.assigns(name);
    };
-    Splat.prototype.compileNode = function(o) {
+    Splat.prototype.compile = function(o) {
      return this.index != null ? this.compileParam(o) : this.name.compile(o);
    };
    Splat.prototype.compileParam = function(o) {
@@ -1182,7 +1166,6 @@
    })();
    __extends(While, Base);
    While.prototype.children = ['condition', 'guard', 'body'];
-    While.prototype.topSensitive = true;
    While.prototype.isStatement = YES;
    While.prototype.addBody = function(body) {
      this.body = body;
@@ -1193,31 +1176,26 @@
      return this;
    };
    While.prototype.compileNode = function(o) {
-      var cond, post, pre, rvar, set, top;
-      top = del(o, 'top') && !this.returns;
+      var body, code, rvar, set;
      o.indent = this.idt(1);
-      cond = this.condition.compile(o, LVL_PAREN);
-      o.top = true;
      set = '';
-      if (!top) {
+      body = this.body;
+      if (o.level > LVL_TOP || this.returns) {
        rvar = o.scope.freeVariable('result');
        set = "" + this.tab + rvar + " = [];\n";
-        if (this.body) {
-          this.body = Push.wrap(rvar, this.body);
+        if (body) {
+          body = Push.wrap(rvar, body);
        }
      }
-      pre = "" + set + this.tab + "while (" + cond + ")";
      if (this.guard) {
-        this.body = Expressions.wrap([new If(this.guard, this.body)]);
+        body = Expressions.wrap([new If(this.guard, body)]);
      }
+      code = set + this.tab + ("while (" + (this.condition.compile(o, LVL_PAREN)) + ") {\n" + (body.compile(o, LVL_TOP)) + "\n" + this.tab + "}");
      if (this.returns) {
-        post = '\n' + new Return(new Literal(rvar)).compile(merge(o, {
-          indent: this.idt()
-        }));
-      } else {
-        post = '';
+        o.indent = this.tab;
+        code += '\n' + new Return(new Literal(rvar)).compile(o);
      }
-      return "" + pre + " {\n" + (this.body.compile(o)) + "\n" + this.tab + "}" + post;
+      return code;
    };
    return While;
  })();
@@ -1278,12 +1256,12 @@
    Op.prototype.toString = function(idt) {
      return Op.__super__.toString.call(this, idt, this.constructor.name + ' ' + this.operator);
    };
+    Op.prototype.unfoldSoak = function(o) {
+      var _ref2;
+      return (_ref2 = this.operator, __indexOf.call(this.MUTATORS, _ref2) >= 0) && If.unfoldSoak(o, this, 'first');
+    };
    Op.prototype.compileNode = function(o) {
-      var _ref2, ifn;
      if (this.isUnary()) {
-        if ((_ref2 = this.operator, __indexOf.call(this.MUTATORS, _ref2) >= 0) && (ifn = If.unfoldSoak(o, this, 'first'))) {
-          return ifn.compile(o);
-        }
        return this.compileUnary(o);
      }
      if (this.isChainable() && this.first.unwrap().isChainable()) {
@@ -1309,7 +1287,7 @@
        fst = this.first;
        ref = fst.compile(o);
      }
-      return new Existence(fst).compile(o) + (" ? " + ref + " : " + (this.second.compile(o, LVL_ASSIGN)));
+      return new Existence(fst).compile(o) + (" ? " + ref + " : " + (this.second.compile(o, LVL_LIST)));
    };
    Op.prototype.compileUnary = function(o) {
      var _ref2, parts, space;
@@ -1394,14 +1372,11 @@
      return this;
    };
    Try.prototype.compileNode = function(o) {
-      var attemptPart, catchPart, errorPart, finallyPart;
+      var catchPart, errorPart;
      o.indent = this.idt(1);
-      o.top = true;
-      attemptPart = this.attempt.compile(o);
      errorPart = this.error ? " (" + (this.error.compile(o)) + ") " : ' ';
-      catchPart = this.recovery ? " catch" + errorPart + "{\n" + (this.recovery.compile(o)) + "\n" + this.tab + "}" : !(this.ensure || this.recovery) ? ' catch (_e) {}' : '';
-      finallyPart = (this.ensure || '') && ' finally {\n' + this.ensure.compile(merge(o)) + ("\n" + this.tab + "}");
-      return "" + this.tab + "try {\n" + attemptPart + "\n" + this.tab + "}" + catchPart + finallyPart;
+      catchPart = this.recovery ? " catch" + errorPart + "{\n" + (this.recovery.compile(o, LVL_TOP)) + "\n" + this.tab + "}" : !(this.ensure || this.recovery) ? ' catch (_e) {}' : undefined;
+      return ("" + this.tab + "try {\n" + (this.attempt.compile(o, LVL_TOP)) + "\n" + this.tab + "}" + (catchPart || '')) + (this.ensure ? " finally {\n" + (this.ensure.compile(o, LVL_TOP)) + "\n" + this.tab + "}" : '');
    };
    return Try;
  })();
@@ -1419,7 +1394,7 @@
    Throw.prototype.isStatement = YES;
    Throw.prototype.makeReturn = THIS;
    Throw.prototype.compileNode = function(o) {
-      return "" + this.tab + "throw " + (this.expression.compile(o)) + ";";
+      return this.tab + ("throw " + (this.expression.compile(o)) + ";");
    };
    return Throw;
  })();
@@ -1453,9 +1428,8 @@
    })();
    __extends(Parens, Base);
    Parens.prototype.children = ['expression'];
-    Parens.prototype.topSensitive = true;
-    Parens.prototype.isStatement = function(o) {
-      return this.expression.isStatement(o);
+    Parens.prototype.unwrap = function() {
+      return this.expression;
    };
    Parens.prototype.isComplex = function() {
      return this.expression.isComplex();
@@ -1464,21 +1438,15 @@
      return this.expression.makeReturn();
    };
    Parens.prototype.compileNode = function(o) {
-      var code, expr, top;
-      top = del(o, 'top');
+      var bare, code, expr;
      expr = this.expression;
      if (expr instanceof Value && expr.isAtomic()) {
        expr.tags.front = this.tags.front;
        return expr.compile(o);
      }
+      bare = o.level < LVL_OP && (expr instanceof Op || expr instanceof Call);
      code = expr.compile(o, LVL_PAREN);
-      if (o.level < LVL_OP && (expr instanceof Op || expr instanceof Call)) {
-        return code;
-      }
-      if (expr.isStatement(o)) {
-        return (top ? this.tab + code + ';' : code);
-      }
-      return "(" + code + ")";
+      return bare ? code : "(" + code + ")";
    };
    return Parens;
  })();
@@ -1505,7 +1473,6 @@
    })();
    __extends(For, Base);
    For.prototype.children = ['body', 'source', 'guard', 'step', 'from', 'to'];
-    For.prototype.topSensitive = true;
    For.prototype.isStatement = YES;
    For.prototype.makeReturn = function() {
      this.returns = true;
@@ -1521,9 +1488,8 @@
      return '';
    };
    For.prototype.compileNode = function(o) {
-      var _ref2, _ref3, _ref4, _ref5, _ref6, body, cond, defPart, forPart, guardPart, idt, index, ivar, lvar, name, namePart, pvar, resultRet, rvar, scope, sourcePart, step, svar, tail, top, tvar, varPart, vars;
+      var _ref2, _ref3, _ref4, _ref5, _ref6, body, cond, defPart, forPart, guardPart, idt, index, ivar, lvar, name, namePart, pvar, resultRet, rvar, scope, sourcePart, step, svar, tail, tvar, varPart, vars;
      scope = o.scope;
-      top = del(o, 'top') && !this.returns;
      name = !this.pattern && ((_ref2 = this.name) != null ? _ref2.compile(o) : undefined);
      index = (_ref3 = this.index) != null ? _ref3.compile(o) : undefined;
      ivar = !index ? scope.freeVariable('i') : index;
@@ -1554,11 +1520,9 @@
        if (name) {
          _ref6 = this.source.compileLoopReference(o, 'ref'), sourcePart = _ref6[0], svar = _ref6[1];
        } else {
-          sourcePart = svar = this.source.compile(o);
+          sourcePart = svar = this.source.compile(o, LVL_PAREN);
        }
-        namePart = this.pattern ? new Assign(this.name, new Literal("" + svar + "[" + ivar + "]")).compile(merge(o, {
-          top: true
-        })) : name ? "" + name + " = " + svar + "[" + ivar + "]" : undefined;
+        namePart = this.pattern ? new Assign(this.name, new Literal("" + svar + "[" + ivar + "]")).compile(o, LVL_TOP) : name ? "" + name + " = " + svar + "[" + ivar + "]" : undefined;
        if (!this.object) {
          if (0 > pvar && (pvar | 0) === +pvar) {
            vars = "" + ivar + " = " + svar + ".length - 1";
@@ -1581,18 +1545,18 @@
        if (svar !== sourcePart) {
          defPart = "" + this.tab + sourcePart + ";\n";
        }
-        forPart = ("" + vars + "; " + cond + "; ") + (function() {
+        forPart = ("" + vars + "; " + cond + "; ") + ivar + (function() {
          switch (+pvar) {
            case 1:
-              return ivar + '++';
+              return '++';
            case -1:
-              return ivar + '--';
+              return '--';
            default:
-              return ivar + (pvar < 0 ? ' -= ' + pvar.slice(1) : ' += ' + pvar);
+              return pvar < 0 ? ' -= ' + pvar.slice(1) : ' += ' + pvar;
          }
        })();
      }
-      if (!top) {
+      if (o.level > LVL_TOP || this.returns) {
        rvar = scope.freeVariable('result');
        defPart += "" + this.tab + rvar + " = [];\n";
        resultRet = this.compileReturnValue(rvar, o);
@@ -1604,10 +1568,8 @@
      if (namePart) {
        varPart = "" + idt + namePart + ";\n";
      }
-      return "" + (defPart || '') + this.tab + "for (" + forPart + ") {\n" + (guardPart || '') + varPart + (body.compile(merge(o, {
-        indent: idt,
-        top: true
-      }))) + "\n" + this.tab + "}" + (resultRet || '');
+      o.indent = idt;
+      return "" + (defPart || '') + this.tab + "for (" + forPart + ") {\n" + (guardPart || '') + varPart + (body.compile(o, LVL_TOP)) + "\n" + this.tab + "}" + (resultRet || '');
    };
    return For;
  })();
@@ -1626,43 +1588,51 @@
    Switch.prototype.children = ['subject', 'cases', 'otherwise'];
    Switch.prototype.isStatement = YES;
    Switch.prototype.makeReturn = function() {
-      var _i, _len, _ref2, pair;
+      var _i, _len, _ref2, _ref3, pair;
      _ref2 = this.cases;
      for (_i = 0, _len = _ref2.length; _i < _len; _i++) {
        pair = _ref2[_i];
        pair[1].makeReturn();
      }
-      if (this.otherwise) {
-        this.otherwise.makeReturn();
+      if ((_ref3 = this.otherwise) != null) {
+        _ref3.makeReturn();
      }
      return this;
    };
    Switch.prototype.compileNode = function(o) {
-      var _i, _j, _len, _len2, _ref2, _ref3, _ref4, block, code, condition, conditions, idt1, idt2;
+      var _i, _j, _len, _len2, _ref2, _ref3, _ref4, _ref5, block, code, cond, conditions, expr, i, idt1, idt2;
      idt1 = this.idt(1);
      idt2 = o.indent = this.idt(2);
-      o.top = true;
-      code = "" + this.tab + "switch (" + (((_ref2 = this.subject) != null ? _ref2.compile(o) : undefined) || true) + ") {";
-      for (_i = 0, _len = this.cases.length; _i < _len; _i++) {
-        _ref3 = this.cases[_i], conditions = _ref3[0], block = _ref3[1];
+      code = this.tab + ("switch (" + (((_ref2 = this.subject) != null ? _ref2.compile(o, LVL_PAREN) : undefined) || true) + ") {\n");
+      for (i = 0, _len = this.cases.length; i < _len; i++) {
+        _ref3 = this.cases[i], conditions = _ref3[0], block = _ref3[1];
        _ref4 = flatten([conditions]);
-        for (_j = 0, _len2 = _ref4.length; _j < _len2; _j++) {
-          condition = _ref4[_j];
+        for (_i = 0, _len2 = _ref4.length; _i < _len2; _i++) {
+          cond = _ref4[_i];
          if (!this.subject) {
-            condition = condition.invert().invert();
+            cond = cond.invert().invert();
          }
-          code += "\n" + idt1 + "case " + (condition.compile(o)) + ":";
+          code += idt1 + ("case " + (cond.compile(o, LVL_PAREN)) + ":\n");
        }
-        code += "\n" + (block.compile(o));
-        if (!(last(block.expressions) instanceof Return)) {
-          code += "\n" + idt2 + "break;";
+        code += block.compile(o, LVL_TOP) + '\n';
+        if (i === this.cases.length - 1 && !this.otherwise) {
+          break;
+        }
+        _ref5 = block.expressions;
+        for (_j = _ref5.length - 1; _j >= 0; _j--) {
+          expr = _ref5[_j];
+          if (!(expr instanceof Comment)) {
+            if (!(expr instanceof Return)) {
+              code += idt2 + 'break;\n';
+            }
+            break;
+          }
        }
      }
      if (this.otherwise) {
-        code += "\n" + idt1 + "default:\n" + (this.otherwise.compile(o));
+        code += idt1 + ("default:\n" + (this.otherwise.compile(o, LVL_TOP)) + "\n");
      }
-      code += "\n" + this.tab + "}";
-      return code;
+      return code + this.tab + '}';
    };
    return Switch;
  })();
@@ -1681,7 +1651,6 @@
    })();
    __extends(If, Base);
    If.prototype.children = ['condition', 'body', 'elseBody'];
-    If.prototype.topSensitive = true;
    If.prototype.bodyNode = function() {
      var _ref2;
      return (_ref2 = this.body) != null ? _ref2.unwrap() : undefined;
@@ -1701,7 +1670,7 @@
    };
    If.prototype.isStatement = function(o) {
      var _ref2;
-      return this.statement || (this.statement = (o != null ? o.top : undefined) || this.bodyNode().isStatement(o) || ((_ref2 = this.elseBodyNode()) != null ? _ref2.isStatement(o) : undefined));
+      return (o != null ? o.level : undefined) === LVL_TOP || this.bodyNode().isStatement(o) || ((_ref2 = this.elseBodyNode()) != null ? _ref2.isStatement(o) : undefined);
    };
    If.prototype.compileNode = function(o) {
      return this.isStatement(o) ? this.compileStatement(o) : this.compileExpression(o);
@@ -1719,13 +1688,12 @@
      return node instanceof Expressions ? node : new Expressions([node]);
    };
    If.prototype.compileStatement = function(o) {
-      var child, condO, ifPart, top;
-      top = del(o, 'top');
+      var body, child, cond, ifPart;
      child = del(o, 'chainChild');
-      condO = merge(o);
+      cond = this.condition.compile(o, LVL_PAREN);
      o.indent = this.idt(1);
-      o.top = true;
-      ifPart = "if (" + (this.condition.compile(condO, LVL_PAREN)) + ") {\n" + (this.body.compile(o)) + "\n" + this.tab + "}";
+      body = this.ensureExpressions(this.body).compile(o);
+      ifPart = "if (" + cond + ") {\n" + body + "\n" + this.tab + "}";
      if (!child) {
        ifPart = this.tab + ifPart;
      }
@@ -1735,11 +1703,11 @@
      return ifPart + ' else ' + (this.isChain ? this.elseBodyNode().compile(merge(o, {
        indent: this.tab,
        chainChild: true
-      })) : "{\n" + (this.elseBody.compile(o)) + "\n" + this.tab + "}");
+      })) : "{\n" + (this.elseBody.compile(o, LVL_TOP)) + "\n" + this.tab + "}");
    };
    If.prototype.compileExpression = function(o) {
      var _ref2, code;
-      code = this.condition.compile(o, LVL_COND) + ' ? ' + this.bodyNode().compile(o, LVL_ASSIGN) + ' : ' + ((_ref2 = this.elseBodyNode()) != null ? _ref2.compile(o, LVL_ASSIGN) : undefined);
+      code = this.condition.compile(o, LVL_COND) + ' ? ' + this.bodyNode().compile(o, LVL_LIST) + ' : ' + ((_ref2 = this.elseBodyNode()) != null ? _ref2.compile(o, LVL_LIST) : undefined);
      return o.level >= LVL_COND ? "(" + code + ")" : code;
    };
    If.prototype.unfoldSoak = function() {
@@ -1801,10 +1769,9 @@
  LVL_TOP = 0;
  LVL_PAREN = 1;
  LVL_LIST = 2;
-  LVL_ASSIGN = 3;
-  LVL_COND = 4;
-  LVL_OP = 5;
-  LVL_ACCESS = 6;
+  LVL_COND = 3;
+  LVL_OP = 4;
+  LVL_ACCESS = 5;
  TAB = '  ';
  TRAILING_WHITESPACE = /[ \t]+$/gm;
  IDENTIFIER = /^[$A-Za-z_][$\w]*$/;
@@ -1817,4 +1784,7 @@
    Scope.root.assign(ref, UTILITIES[name]);
    return ref;
  };
+  multident = function(code, tab) {
+    return code.replace(/\n/g, '$&' + tab);
+  };
 }).call(this);