From 0f2a2ee11e651a547f97a7255907ceb67ca3eac3 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Sat, 20 Feb 2010 20:00:07 -0500
Subject: [PATCH] Improving soaks to avoid uncessesary parentheses.

---
 lib/nodes.js               | 18 +++++++++++++-----
 src/nodes.coffee           | 20 +++++++++++++-------
 test/test_existence.coffee | 13 +++++++++++++
 3 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/lib/nodes.js b/lib/nodes.js
index c05f9cdb..2f2fc7a8 100644
--- a/lib/nodes.js
+++ b/lib/nodes.js
@@ -99,6 +99,9 @@
     var closure, top;
     this.options = merge(o || {});
     this.indent = o.indent;
+    if (!(this.operation_sensitive())) {
+      del(this.options, 'operation');
+    }
     top = this.top_sensitive() ? this.options.top : del(this.options, 'top');
     closure = this.is_statement() && !this.is_statement_only() && !top && !this.options.returns && !(this instanceof CommentNode) && !this.contains(function(node) {
       return node.is_statement_only();
@@ -164,6 +167,9 @@
   Node.prototype.top_sensitive = function top_sensitive() {
     return false;
   };
+  Node.prototype.operation_sensitive = function operation_sensitive() {
+    return false;
+  };
   // A collection of nodes, each one representing an expression.
   Expressions = (exports.Expressions = inherit(Node, {
     type: 'Expressions',
@@ -326,6 +332,9 @@
       this.children.push(prop);
       return this;
     },
+    operation_sensitive: function operation_sensitive() {
+      return true;
+    },
     has_properties: function has_properties() {
       return !!this.properties.length;
     },
@@ -349,9 +358,10 @@
       return this.base.is_statement && this.base.is_statement() && !this.has_properties();
     },
     compile_node: function compile_node(o) {
-      var _a, _b, baseline, code, only, part, parts, prop, props, soaked, temp;
+      var _a, _b, baseline, code, only, op, part, parts, prop, props, soaked, temp;
       soaked = false;
       only = del(o, 'only_first');
+      op = del(o, 'operation');
       props = only ? this.properties.slice(0, this.properties.length - 1) : this.properties;
       baseline = this.base.compile(o);
       if (this.base instanceof ObjectNode && this.has_properties()) {
@@ -378,10 +388,7 @@
       this.last = parts[parts.length - 1];
       this.source = parts.length > 1 ? parts.slice(0, (parts.length - 1)).join('') : null;
       code = parts.join('').replace(/\)\(\)\)/, '()))');
-      if (!(soaked)) {
-        return code;
-      }
-      return '(' + code + ')';
+      return op && soaked ? '(' + code + ')' : code;
     }
   }));
   // Pass through CoffeeScript comments into JavaScript comments at the
@@ -943,6 +950,7 @@
       return this.CHAINABLE.indexOf(this.operator) >= 0;
     },
     compile_node: function compile_node(o) {
+      o.operation = true;
       if (this.is_chainable() && this.first.unwrap() instanceof OpNode && this.first.unwrap().is_chainable()) {
         return this.compile_chain(o);
       }
diff --git a/src/nodes.coffee b/src/nodes.coffee
index c4a7131c..a7d5a026 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -63,6 +63,7 @@ Node: exports.Node: ->
 Node::compile: (o) ->
   @options: merge o or {}
   @indent:  o.indent
+  del @options, 'operation' unless @operation_sensitive()
   top:      if @top_sensitive() then @options.top else del @options, 'top'
   closure:  @is_statement() and not @is_statement_only() and not top and
             not @options.returns and not (this instanceof CommentNode) and
@@ -95,11 +96,12 @@ Node::toString: (idt) ->
   '\n' + idt + @type + (child.toString(idt + TAB) for child in @children).join('')
 
 # Default implementations of the common node methods.
-Node::unwrap:             -> this
-Node::children:           []
-Node::is_statement:       -> false
-Node::is_statement_only:  -> false
-Node::top_sensitive:      -> false
+Node::unwrap:               -> this
+Node::children:             []
+Node::is_statement:         -> false
+Node::is_statement_only:    -> false
+Node::top_sensitive:        -> false
+Node::operation_sensitive:  -> false
 
 # A collection of nodes, each one representing an expression.
 Expressions: exports.Expressions: inherit Node, {
@@ -239,6 +241,9 @@ ValueNode: exports.ValueNode: inherit Node, {
     @children.push(prop)
     this
 
+  operation_sensitive: ->
+    true
+
   has_properties: ->
     !!@properties.length
 
@@ -264,6 +269,7 @@ ValueNode: exports.ValueNode: inherit Node, {
   compile_node: (o) ->
     soaked:   false
     only:     del(o, 'only_first')
+    op:       del(o, 'operation')
     props:    if only then @properties[0...@properties.length - 1] else @properties
     baseline: @base.compile o
     baseline: '(' + baseline + ')' if @base instanceof ObjectNode and @has_properties()
@@ -285,8 +291,7 @@ ValueNode: exports.ValueNode: inherit Node, {
     @last: parts[parts.length - 1]
     @source: if parts.length > 1 then parts[0...(parts.length - 1)].join('') else null
     code: parts.join('').replace(/\)\(\)\)/, '()))')
-    return code unless soaked
-    '(' + code + ')'
+    if op and soaked then '(' + code + ')' else code
 
 }
 
@@ -757,6 +762,7 @@ OpNode: exports.OpNode: inherit Node, {
     @CHAINABLE.indexOf(@operator) >= 0
 
   compile_node: (o) ->
+    o.operation: true
     return @compile_chain(o)      if @is_chainable() and @first.unwrap() instanceof OpNode and @first.unwrap().is_chainable()
     return @compile_assignment(o) if @ASSIGNMENT.indexOf(@operator) >= 0
     return @compile_unary(o)      if @is_unary()
diff --git a/test/test_existence.coffee b/test/test_existence.coffee
index c08d8151..502e8f6f 100644
--- a/test/test_existence.coffee
+++ b/test/test_existence.coffee
@@ -55,3 +55,16 @@ ok arr.pop()?.length is 2
 ok arr.pop()?.length is undefined
 ok arr[0]?.length is undefined
 ok arr.pop()?.length?.non?.existent()?.property is undefined
+
+
+# Soaks method calls safely.
+value: undefined
+result: value?.toString().toLowerCase()
+
+ok result is undefined
+
+value: 10
+result: value?.toString().toLowerCase()
+
+ok result is '10'
+