functional

lib/functional.rb

@@ -0,0 +1,46 @@
+
+class Functional
+	include Enumerable
+
+	def self.method_missing meth, *args, &exe
+		self.new.send meth, *args, &exe
+	end
+
+	def push_method code, *args, &exe
+		name = "__meth_#{exe.object_id}"
+		define_singleton_method name, &exe
+		@stack.push [code % name]+args
+		self
+	end
+
+	def initialize obj = nil, func = nil, *args
+		@stack, @obj, @func, @args = [], obj, func, args
+	end
+
+	def collect &exe
+		push_method "value=%s(value)", &exe
+	end
+
+=begin
+	# map/reduce?
+	def map &exe
+		push_method "value=%s(value)", &exe
+	end
+=end
+	def select &exe
+		push_method "%s(value)||next", &exe
+	end
+
+	def delete_if &exe
+		push_method "%s(value)&&next", &exe
+	end
+
+	def each obj, &exe
+		return Enumerator.new self, :each, obj  unless exe
+		obj.each &eval( "lambda{|value|#{@stack.join( ";")};exe.call(value)}")
+	end
+
+	def inject obj, start, &exe
+		each( obj).inject start, &exe
+	end
+end