From: daz <dooby@...10.karoo.co.uk>
Date: 2005-11-18T01:32:19+09:00
Subject: Re: Ruby style question from a newby: exceptions


YANAGAWA Kazuhisa wrote:
>
>     irb(main):019:1>   retry if c < 5


Hi Richard,

Here's a variation on that theme:

#--------------------------------------------------------

METHOD_Q = [ [:aaa, TypeError],
             [:bbb, NoMethodError],
             [:ccc, ArgumentError],
             [:ddd, NameError],
           ].freeze

def log(item); puts "LOG: #{item}"; end

def aaa;  11 + 'Two Two'; end
def bbb;  12.sort; end
def ccc;  [].each(13) {}; end
def ddd
  puts "4th attempt"
  # NOCONST   # <--- uncomment
end


catch(:done) do
  stack = METHOD_Q.dup
  begin
    meth, exc = stack.shift
    unless meth
      log "Tried everything :("
      throw(:done)
    end
    send(meth)
    log "Success at last!"
  rescue exc => e
    log "#{meth} error"
    log "^ #{e.message}"
    retry
  end
end

=begin

LOG: aaa error
LOG: ^ String can't be coerced into Fixnum
LOG: bbb error
LOG: ^ undefined method `sort' for 12:Fixnum
LOG: ccc error
LOG: ^ wrong number of arguments (1 for 0)
4th attempt
LOG: Success at last!

=end
#--------------------------------------------------------


daz