From: Dave Thomas <Dave@...>
Date: 2002-01-28T07:58:36+09:00
Subject: Re: how to find out which args a method can take

Tobias Reif <tobiasreif@pinkjuice.com> writes:

> I know that I can pass wide varieties to some methods. What I thought 
> was: perhaps there are any built-in documentation like info bits that 
> can help whan generating "tests" for built-in methiods. Something like
> Array.works_with_args?('join')    # -> [[String]]
> String.works_with_args('sub')     # -> [[Regex,String], [Regex, Block]]
> String.works_with_args('reverse') # -> []

But... Ruby classes are not types in this sense (although admittedly
it works 99% of the time). For example,

  irbsh(main):001:0> e = Exception.new("hello")
  #<Exception: hello>
  irbsh(main):002:0> "123".sub(/./, e)
  "hello23"


You _could_ find out some of the information you need by trying things
and catching the TypeError exception, but that seems like a lot of
work :)



Dave