require 'parse_tree'
require 'ruby2ruby'
class ParseTreeArray < Array
R2R = Object.const_defined?(:Ruby2Ruby) ? Ruby2Ruby : RubyToRuby
def self.translate(*args)
sexp = ParseTree.translate(*args)
# ParseTree.translate returns [nil] if called on an inherited method, so walk
# up the inheritance chain to find the class that the method was defined in
unless sexp.first
klass = args.first.ancestors.detect do |klass|
klass.public_instance_methods(false).include?(args.last.to_s)
end
sexp = ParseTree.translate(klass, args.last) if klass
end
sexp = Unifier.new.process(sexp)
self.new(sexp)
end
def deep_array_node(type = nil)
each do |node|
return ParseTreeArray.new(node) if node.is_a?(Array) && (!type || node[0] == type)
next unless node.is_a?(Array)
return ParseTreeArray.new(node).deep_array_node(type)
end
nil
end
def arg_nodes
self[1..-1].inject([]) do |sum,item|
sum << [item] unless item.is_a?(Array)
sum
end
end
def get_args
if arg_node = deep_array_node(:args)
# method defined with def keyword
args = arg_node.arg_nodes
default_node = arg_node.deep_array_node(:block)
return [args, []] unless default_node
else
# assuming method defined with Module#define_method
return [[],[]]
end
# if it was defined with def, and we found the default_node,
# that should bring us back to regularly scheduled programming..
lasgns = default_node[1..-1]
lasgns.each do |asgn|
args.assoc(asgn[1]) << eval(R2R.new.process(asgn[2]))
end
[args, (default_node[1..-1].map { |asgn| asgn[1] })]
end
end
# Used in mapping controller arguments to the params hash.
# NOTE: You must have the 'ruby2ruby' gem installed for this to work.
#
# ==== Examples
# # In PostsController
# def show(id) #=> id is the same as params[:id]
module GetArgs
# ==== Returns
# Array:: Method arguments and their default values.
#
# ==== Examples
# class Example
# def hello(one,two="two",three)
# end
#
# def goodbye
# end
# end
#
# Example.instance_method(:hello).get_args
# #=> [[:one], [:two, "two"], [:three, "three"]]
# Example.instance_method(:goodbye).get_args #=> nil
def get_args
klass, meth = self.to_s.split(/ /).to_a[1][0..-2].split("#")
# Remove stupidity for #<Method: Class(Object)#foo>
klass = $` if klass =~ /\(/
ParseTreeArray.translate(Object.full_const_get(klass), meth).get_args
end
end
