@@ -1,9 +1,11 @@ == 1.0.4 / 2008-11-17 -* 3 minor enhancements +* 4 minor enhancements * Updated array traversal code to be recursive by default * Updated visitor code to use class instances instead of class-level methods for greater flexibility * Updated error handling to include parsing context in error message + * Added clone method for deep copy of AST + * Updated node building to set node parents for easier traversal of the AST == 1.0.0 / 2008-06-29 History.txt @@ -31,6 +31,8 @@ module TireSwing @attribute_mapping ||= {} end + attr_accessor :parent + # Instantiate a node. # # Values can either be a hash of values to set the values of this node's attributes, or a Treetop syntax node @@ -57,15 +59,7 @@ module TireSwing def build_from_parsed_node(parsed_node) attributes.each do |attrib| if handler = mapping(attrib) - if handler.kind_of?(Proc) - value = handler.call(parsed_node) - else - if parsed_node.respond_to?(handler) - value = parsed_node.send(handler) - else - value = parsed_node.text_value.send(handler) - end - end + value = apply_mapping(handler, parsed_node) else value = parsed_node.send(attrib) end @@ -80,9 +74,25 @@ module TireSwing end end + def apply_mapping(handler, parsed_node) + # TODO add in handler for arrays of methods to call in order + if handler.kind_of?(Proc) + value = handler.call(parsed_node) + else + # TODO need to add more error checking + if parsed_node.respond_to?(handler) + value = parsed_node.send(handler) + else + value = parsed_node.text_value.send(handler) + end + end + end + def extract_value(value) if value.respond_to?(:build) - value.build + node = value.build + node.parent = self if node.kind_of?(Node) + node elsif value.kind_of?(Treetop::Runtime::SyntaxNode) value.text_value else lib/tire_swing/node.rb @@ -2,15 +2,16 @@ module TireSwing::NodeDefinition module ModuleMethods - # Returns a NodeCreator to act as a stand-in for a normal node class definition. + # Returns a NodeCreator to act as a stand-in for a node class in the treetop parser. # According to the treetop metagrammar, node class definitions can have more than just a class in them. - # For example: + # + # Given the initial grammar, # # rule variable # [a-z]+ <Variable> # end # - # Instead, use this method to use AST node auto-build functionality. Given + # you might instead use use the AST node auto-build functionality. Given # # node :variable, :value => :text_value # @@ -20,6 +21,8 @@ module TireSwing::NodeDefinition # [a-z]+ <node(:variable)> # end # + # and voila, you'll magically have a Variable node with a #value attribute containing the text value. + # # Also note that you can specify alternate namespaces: # # module AST @@ -28,15 +31,15 @@ module TireSwing::NodeDefinition # # <AST.create_node(:variable)> # - # When you're using the parser extension: + # and when you're using the parser extension, tell the parser about the namespace # # TireSwing.parses_grammar(Grammar, AST) # - # you can use + # and then you can use the shortest possible syntax, # # <node(...)> # - # Which is an instance method wrapper for the create_node class method. + # which is an instance method wrapper for the create_node class method. # def create_node(name) TireSwing::NodeCreator.new(name, const_get(name.to_s.camelize)) lib/tire_swing/node_definition.rb @@ -2,6 +2,13 @@ require File.join(File.dirname(__FILE__), %w[spec_helper]) describe TireSwing::Node do + it "has a parent accessor" do + node = TireSwing::Node.new + node.parent.should be_nil + node.parent = :parent + node.parent.should == :parent + end + describe ".create" do it "returns a class that inherits from TireSwing::Node" do klass = TireSwing::Node.create @@ -120,6 +127,16 @@ describe TireSwing::Node do TireSwing::Node.create(:foo => :children).new(@top).foo.should == ["foo", 1, "child"] end + it "assigns the parent node if the child node is also a TireSwing node" do + @top.should_receive(:child).and_return(@child) + node = TireSwing::Node.create(:foo => :child) + child_node = TireSwing::Node.new + @child.should_receive(:build).and_return(child_node) + new_top = node.new(@top) + new_top.foo.should == child_node + child_node.parent.should == new_top + end + end it "yields the syntax node instance if a named attribute is a lambda" do @@ -141,7 +158,7 @@ describe TireSwing::Node do describe "#clone" do it "does a deep copy of a node" do - # can't leave this as an anonymous class, marshal dump/load don't like it + # can't leave this as an anonymous class, marshal dump/load doesn't like it MyNode = TireSwing::Node.create node = MyNode.new node.clone.should_not eql node spec/node_spec.rb b3850b22cb77f2bccc959ce43136481eb78a7f5b Nathan Witmer nwitmer@gmail.com http://github.com/aniero/tire_swing/commit/0da39edd937c82769b7a8d075ccb63a011c13d5a 0da39edd937c82769b7a8d075ccb63a011c13d5a 2008-11-18T16:21:57-08:00 2008-11-18T07:33:30-08:00 Added parent tracking for nodes f64f45692c8eccc41e61c4901d99f99311cc522b Nathan Witmer nwitmer@gmail.com