From 78c4957ba87f95e2f7a28908fcb37743b8e94cfe Mon Sep 17 00:00:00 2001 From: Jeremy Ashkenas Date: Sun, 3 Jan 2010 13:59:17 -0500 Subject: [PATCH] first rough rough rough draft of kamatsu's closure suggestion -- test.coffee runs, but probably nothing else --- lib/coffee_script/grammar.y | 12 +-- lib/coffee_script/nodes.rb | 178 ++++++++++-------------------------- lib/coffee_script/scope.rb | 13 +-- 3 files changed, 62 insertions(+), 141 deletions(-) diff --git a/lib/coffee_script/grammar.y b/lib/coffee_script/grammar.y index f821370d..4810adf1 100644 --- a/lib/coffee_script/grammar.y +++ b/lib/coffee_script/grammar.y @@ -43,14 +43,14 @@ rule # All parsing will end in this rule, being the trunk of the AST. Root: - /* nothing */ { result = Expressions.new([]) } - | Terminator { result = Expressions.new([]) } + /* nothing */ { result = Expressions.new } + | Terminator { result = Expressions.new } | Expressions { result = val[0] } ; # Any list of expressions or method body, seperated by line breaks or semis. Expressions: - Expression { result = Expressions.new(val) } + Expression { result = Expressions.wrap(val) } | Expressions Terminator Expression { result = val[0] << val[2] } | Expressions Terminator { result = val[0] } ; @@ -78,7 +78,7 @@ rule Block: INDENT Expressions OUTDENT { result = val[1] } - | INDENT OUTDENT { result = Expressions.new([]) } + | INDENT OUTDENT { result = Expressions.new } ; # All tokens that can terminate an expression. @@ -405,8 +405,8 @@ rule # The full complement of if blocks, including postfix one-liner ifs and unlesses. If: IfBlock IfEnd { result = val[0].add_else(val[1]) } - | Expression IF Expression { result = IfNode.new(val[2], Expressions.new([val[0]]), nil, {:statement => true}) } - | Expression UNLESS Expression { result = IfNode.new(val[2], Expressions.new([val[0]]), nil, {:statement => true, :invert => true}) } + | Expression IF Expression { result = IfNode.new(val[2], Expressions.wrap(val[0]), nil, {:statement => true}) } + | Expression UNLESS Expression { result = IfNode.new(val[2], Expressions.wrap(val[0]), nil, {:statement => true, :invert => true}) } ; end diff --git a/lib/coffee_script/nodes.rb b/lib/coffee_script/nodes.rb index e7c3ecf8..c9f2fd7d 100644 --- a/lib/coffee_script/nodes.rb +++ b/lib/coffee_script/nodes.rb @@ -11,17 +11,11 @@ module CoffeeScript class_eval "def statement?; true; end" end - # Tag this node as having a custom return, meaning that instead of returning - # it from the outside, you ask it to return itself, and it obliges. - def self.custom_return - class_eval "def custom_return?; true; end" - end - - # Tag this node as having a custom assignment, meaning that instead of - # assigning it to a variable name from the outside, you pass it the variable - # name and let it take care of it. - def self.custom_assign - class_eval "def custom_assign?; true; end" + # Tag this node as a statement that cannot be transformed into an expression. + # (break, continue, etc.) It doesn't make sense to try to transform it. + def self.statement_only + statement + class_eval "def statement_only?; true; end" end def write(code) @@ -33,29 +27,31 @@ module CoffeeScript @options = o.dup end + def compile_closure(o={}) + "(#{CodeNode.new([], Expressions.wrap(self)).compile(o, o[:scope])})()" + end + # Default implementations of the common node methods. - def unwrap; self; end - def line_ending; ';'; end - def statement?; false; end - def custom_return?; false; end - def custom_assign?; false; end + def unwrap; self; end + def statement?; false; end + def statement_only?; false; end end # A collection of nodes, each one representing an expression. class Expressions < Node statement - custom_assign attr_reader :expressions STRIP_TRAILING_WHITESPACE = /\s+$/ # Wrap up a node as an Expressions, unless it already is. - def self.wrap(node) - node.is_a?(Expressions) ? node : Expressions.new([node]) + def self.wrap(*nodes) + return nodes[0] if nodes.length == 1 && nodes[0].is_a?(Expressions) + Expressions.new(*nodes) end - def initialize(nodes) - @expressions = nodes + def initialize(*nodes) + @expressions = nodes.flatten end # Tack an expression onto the end of this node. @@ -83,43 +79,36 @@ module CoffeeScript # If this is the top-level Expressions, wrap everything in a safety closure. def root_compile(o={}) indent = o[:no_wrap] ? '' : TAB - code = compile(o.merge(:indent => indent, :scope => Scope.new), o[:no_wrap] ? nil : :code) + code = compile(o.merge(:indent => indent, :scope => Scope.new(nil, self)), o[:no_wrap] ? nil : :code) code.gsub!(STRIP_TRAILING_WHITESPACE, '') o[:no_wrap] ? code : "(function(){\n#{code}\n})();" end - # The extra fancy is to handle pushing down returns and assignments - # recursively to the final lines of inner statements. - # Variables first defined within the Expressions body have their - # declarations pushed up to the top scope. + # The extra fancy is to handle pushing down returns to the final lines of + # inner statements. Variables first defined within the Expressions body + # have their declarations pushed up top of the closest scope. def compile(options={}, parent=nil) return root_compile(options) unless options[:scope] compiled = @expressions.map do |node| o = super(options) - if last?(node) && (o[:return] || o[:assign]) - if o[:return] - if node.statement? || node.custom_return? - "#{node.compile(o)}#{node.line_ending}" - else - o.delete(:return) - "#{o[:indent]}return #{node.compile(o)}#{node.line_ending}" - end - elsif o[:assign] - if node.statement? || node.custom_assign? - "#{node.compile(o)}#{node.line_ending}" - else - "#{o[:indent]}#{AssignNode.new(o[:assign], node).compile(o)};" - end + returns = o.delete(:return) + code = node.compile(o) + if last?(node) && returns && !node.statement_only? + if node.statement? + node.compile(o.merge(:return => true)) + else + "#{o[:indent]}return #{node.compile(o)};" end else - o.delete(:return) and o.delete(:assign) - indent = node.unwrap.statement? ? '' : o[:indent] - "#{indent}#{node.compile(o)}#{node.line_ending}" + ending = node.statement_only? ? '' : ';' + indent = node.statement? ? '' : o[:indent] + "#{indent}#{node.compile(o)}#{ending}" end end scope = options[:scope] - declarations = scope.any_declared? && parent == :code ? "#{options[:indent]}var #{scope.declared_variables.join(', ')};\n" : '' - code = declarations + compiled.join("\n") + decls = '' + decls = "#{options[:indent]}var #{scope.declared_variables.join(', ')};\n" if parent == :code && scope.declarations?(self) + code = decls + compiled.join("\n") write(code) end end @@ -138,10 +127,7 @@ module CoffeeScript def statement? STATEMENTS.include?(@value.to_s) end - - def line_ending - @value.to_s[-1..-1] == ';' ? '' : ';' - end + alias_method :statement_only?, :statement? def compile(o={}) o = super(o) @@ -152,8 +138,7 @@ module CoffeeScript # Try to return your expression, or tell it to return itself. class ReturnNode < Node - statement - custom_return + statement_only attr_reader :expression @@ -161,10 +146,6 @@ module CoffeeScript @expression = expression end - def line_ending - @expression.custom_return? ? '' : ';' - end - def compile(o={}) o = super(o) return write(@expression.compile(o.merge(:return => true))) if @expression.custom_return? @@ -176,16 +157,12 @@ module CoffeeScript # Pass through CoffeeScript comments into JavaScript comments at the # same position. class CommentNode < Node - statement + statement_only def initialize(lines) @lines = lines.value end - def line_ending - '' - end - def compile(o={}) delimiter = "\n#{o[:indent]}//" comment = "#{delimiter}#{@lines.join(delimiter)}" @@ -253,6 +230,7 @@ module CoffeeScript # Node to extend an object's prototype with an ancestor object. # After goog.inherits from the Closure Library. class ExtendsNode < Node + statement attr_reader :sub_object, :super_object def initialize(sub_object, super_object) @@ -289,14 +267,6 @@ module CoffeeScript @literal.is_a?(Node) && @literal.statement? && !properties? end - def custom_assign? - @literal.is_a?(Node) && @literal.custom_assign? && !properties? - end - - def custom_return? - @literal.is_a?(Node) && @literal.custom_return? && !properties? - end - def compile(o={}) o = super(o) only = o.delete(:only_first) @@ -401,35 +371,25 @@ module CoffeeScript PROTO_ASSIGN = /\A(\S+)\.prototype/ LEADING_DOT = /\A\./ - custom_return - attr_reader :variable, :value, :context def initialize(variable, value, context=nil) @variable, @value, @context = variable, value, context end - def line_ending - @value.custom_assign? ? '' : ';' - end - - def statement? - @value.custom_assign? - end - def compile(o={}) o = super(o) return compile_splice(o) if @variable.properties.last.is_a?(SliceNode) name = @variable.compile(o) last = @variable.last.to_s.sub(LEADING_DOT, '') proto = name[PROTO_ASSIGN, 1] - o = o.merge(:assign => @variable, :last_assign => last, :proto_assign => proto) + o = o.merge(:last_assign => last, :proto_assign => proto) o[:immediate_assign] = last if @value.is_a?(CodeNode) && last.match(Lexer::IDENTIFIER) return write("#{name}: #{@value.compile(o)}") if @context == :object o[:scope].find(name) unless @variable.properties? - return write(@value.compile(o)) if @value.custom_assign? - val = "#{name} = #{@value.compile(o)}" - write(o[:return] && !@value.custom_return? ? "#{o[:indent]}return (#{val})" : val) + code = @value.statement? ? @value.compile_closure(o) : @value.compile(o) + val = "#{name} = #{code}" + write(o[:return] ? "#{o[:indent]}return (#{val})" : val) end def compile_splice(o) @@ -498,13 +458,12 @@ module CoffeeScript @body = body end - def compile(o={}) + def compile(o={}, shared_scope=nil) o = super(o) - o[:scope] = Scope.new(o[:scope]) + o[:scope] = shared_scope || Scope.new(o[:scope], @body) o[:return] = true indent = o[:indent] o[:indent] += TAB - o.delete(:assign) o.delete(:no_wrap) name = o.delete(:immediate_assign) if @params.last.is_a?(ParamSplatNode) @@ -604,10 +563,6 @@ module CoffeeScript @condition, @body = condition, body end - def line_ending - '' - end - def compile(o={}) o = super(o) o.delete(:return) @@ -623,8 +578,6 @@ module CoffeeScript # the current index of the loop as a second parameter. class ForNode < Node statement - custom_return - custom_assign attr_reader :body, :source, :name, :index, :filter, :step @@ -635,10 +588,6 @@ module CoffeeScript @step = source[:step] end - def line_ending - '' - end - def compile(o={}) o = super(o) range = @source.is_a?(RangeNode) @@ -668,14 +617,12 @@ module CoffeeScript set_result = "#{rvar} = [];\n#{o[:indent]}" return_result = rvar temp_var = ValueNode.new(LiteralNode.new(tvar)) - body = Expressions.new([ + body = Expressions.wrap( AssignNode.new(temp_var, @body), CallNode.new(ValueNode.new(LiteralNode.new(rvar), [AccessorNode.new('push')]), [temp_var]) - ]) - if o[:return] || o[:assign] - return_result = "#{o[:assign].compile(o)} = #{return_result}" if o[:assign] + ) + if o[:return] return_result = "return #{return_result}" if o[:return] - o.delete(:assign) o.delete(:return) body = IfNode.new(@filter, body, nil, :statement => true) if @filter elsif @filter @@ -691,8 +638,6 @@ module CoffeeScript # A try/catch/finally block. class TryNode < Node statement - custom_return - custom_assign attr_reader :try, :error, :recovery, :finally @@ -700,24 +645,20 @@ module CoffeeScript @try, @error, @recovery, @finally = try, error, recovery, finally end - def line_ending - '' - end - def compile(o={}) o = super(o) indent = o[:indent] o[:indent] += TAB error_part = @error ? " (#{@error}) " : ' ' catch_part = @recovery && " catch#{error_part}{\n#{@recovery.compile(o)}\n#{indent}}" - finally_part = @finally && " finally {\n#{@finally.compile(o.merge(:assign => nil, :return => nil))}\n#{indent}}" + finally_part = @finally && " finally {\n#{@finally.compile(o.merge(:return => nil))}\n#{indent}}" write("#{indent}try {\n#{@try.compile(o)}\n#{indent}}#{catch_part}#{finally_part}") end end # Throw an exception. class ThrowNode < Node - statement + statement_only attr_reader :expression @@ -760,14 +701,6 @@ module CoffeeScript @expressions.unwrap.statement? end - def custom_assign? - @expressions.custom_assign? - end - - def custom_return? - @expressions.custom_return? - end - def compile(o={}) raise SyntaxError, "line #{@line}: parentheses can't be wrapped around a statement" if statement? o = super(o) @@ -827,18 +760,6 @@ module CoffeeScript @is_statement ||= !!(@tags[:statement] || @body.statement? || (@else_body && @else_body.statement?)) end - def custom_return? - statement? - end - - def custom_assign? - statement? - end - - def line_ending - statement? ? '' : ';' - end - def compile(o={}) o = super(o) write(statement? ? compile_statement(o) : compile_ternary(o)) @@ -850,7 +771,6 @@ module CoffeeScript indent = o[:indent] child = o.delete(:chain_child) cond_o = o.dup - cond_o.delete(:assign) cond_o.delete(:return) o[:indent] += TAB if_dent = child ? '' : indent diff --git a/lib/coffee_script/scope.rb b/lib/coffee_script/scope.rb index 5e510b12..303e5f2b 100644 --- a/lib/coffee_script/scope.rb +++ b/lib/coffee_script/scope.rb @@ -5,11 +5,12 @@ module CoffeeScript # whether a variable has been seen before or if it needs to be declared. class Scope - attr_reader :parent, :variables, :temp_variable + attr_reader :parent, :expressions, :variables, :temp_variable - # Initialize a scope with its parent, for lookups up the chain. - def initialize(parent=nil) - @parent = parent + # Initialize a scope with its parent, for lookups up the chain, + # as well as the Expressions body where it should declare its variables. + def initialize(parent, expressions) + @parent, @expressions = parent, expressions @variables = {} @temp_variable = @parent ? @parent.temp_variable : '__a' end @@ -46,8 +47,8 @@ module CoffeeScript @temp_variable.dup end - def any_declared? - !declared_variables.empty? + def declarations?(body) + !declared_variables.empty? && body == @expressions end # Return the list of variables first declared in current scope.