From: Robert Klemme <bob.news@...>
Date: 2006-02-14T18:38:25+09:00
Subject: Re: Generic method without case/when?

Paatsch, Bernd wrote:
> I like to write a generic method that calls different functions
> depending on what string I parse to the method (see example) without
> having to use a case-when? Is there a way to do that?
>
> Process_easy("aFile", "Summer")
>
> def process_easy(file, what)
>
>     if file.include?("#{what}#{NL}") then
>       constructor = CategoriesFactory.start_what # this is wrong. I
> like to substitute and have:  constructor =
>       CategoriesFactory.start_summer start = file.index("Summer#{NL}")
>       return constructor
> # etc
> end


Difficult to tell from this example.  You could use send as Tim suggested.
But you might as well use a different approach:

 - extract a class name from the string
 - extract another string from the string and map that via a Hash to a
lambda / class whatever

MAP = {
  "what" => lambda {|x| puts "doing what #{x}"},
  "Summer" => lambda {|x| puts "it's summer"},
}
def process_easy(file)
  cmd = MAP[file[/\w+$/m]] and cmd[file]
end

Kind regards

    robert