Would someone please tell me how to make methods that have other methods as parameters? (My ultimate goal is to teach Ruby basic calculus.) For example, I'd like something on the order of: def at_zero(m()) # pickaxe says "you must use parentheses # on a method call which is itself a # parameter to another method" m(0) end When I try this, I run into trouble: irb(main):001:0> require 'mathn' true irb(main):002:0> include Math Object irb(main):003:0> sin(0) 0.0 irb(main):004:0> def at_zero(m()) # first cut irb(main):005:1> m(0) irb(main):006:1> end SyntaxError: compile error (irb):4: parse error def at_zero(m()) ^ (irb):6: parse error from (irb):6 irb(main):007:0> class Method # maybe I can get sin.at_zero irb(main):008:1> def at_zero irb(main):009:2> self(0) irb(main):010:2> end irb(main):011:1> end SyntaxError: compile error (irb):9: parse error self(0) ^ from (irb):11 irb(main):012:0> def at_zero(m) irb(main):013:1> m(0) irb(main):014:1> end nil irb(main):015:0> sin(0) 0.0 irb(main):016:0> at_zero(sin()) ArgumentError: wrong # of arguments(0 for 1) from (irb):16:in `sin' from (irb):16 irb(main):017:0> at_zero(sin) ArgumentError: wrong # of arguments(0 for 1) from (irb):17:in `sin' from (irb):17 irb(main):018:0> at_zero(:sin) # desperation NameError: undefined method `m' for #<Object:0x401ddc90> from (irb):13:in `at_zero' from (irb):18 irb(main):019:0> class Method # try with explicit "self" param irb(main):020:1> def at_zero(self) irb(main):021:2> self(0) irb(main):022:2> end irb(main):023:1> end SyntaxError: compile error (irb):20: parse error def at_zero(self) ^ from (irb):23 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Help, please! Doomoo arigatoo Regards, Bret Jolly (Jou Lii Bair) For email, please remove the cow noises and underbar from my domain name. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =-----