module Parser module FunctionDefinition include Parslet rule(:function_definition) { keyword_def >> name.as(:function_definition) >> parmeter_list >> newline >> expressions_end } rule(:parmeter_list) { left_parenthesis >> ((name.as(:parmeter) >> (comma >> name.as(:parmeter)).repeat(0)).repeat(0,1)).as(:parmeter_list) >> right_parenthesis } end end