From: "T. Onoma" <transami@...>
Date: 2003-11-22T20:11:03+09:00
Subject: Re: "stereotyping"

Sorry I forgot to post results of DuckHunter examples. (DuckHunter itself is 
also included below).

DuckHunter is a concise probe providing the functionality of #duck_signature, 
and has a unique feature that suggests how Ruby might proceed to cleaning up 
some of its code: If a type error returns the method that was not implemented 
in the error message then DuckHunter will fix and continue to probe. Using 
this on a number of libraries I have discoverd that ruby has a problem in 
that it allows TypeError to be raised for any reason whatsoever. There needs 
to be a tighter system for raising TypeErrors, including returning the 
offened method. I believe that one of the first things that needs to happen 
to improve Ruby's type mechanics is to ensure that a signature probe can run 
without fail on any method.

Results:

DUCK QUACKS

big4:
        succ()
        to_i()
        >()
        >(Fixnum)

DUCK QUACKS
#<DuckHunter:0x402a8738>
#<DuckHunter:0x402a8738>
#<DuckHunter:0x402a8738>
#<DuckHunter:0x402a8738>

ameth:
        succ()
        jump(Fixnum)
        to_i()
        to_i()
        >()
        >(Fixnum)
        do_what_ever(String,Regexp)
        do_what_ever(String,Regexp,Fixnum)

-t0


On Saturday 22 November 2003 02:22 am, T. Onoma wrote:
> and i thought it was so radical when i wrote it yesterday
>
> # notice if TypeErrors woud return offending respond_to? method
> # in error message then it would continue to probe
>
> class DuckHunter
>
>   def initialize
>     @a_r_g_s = {}
>   end
>
>   def a_r_g_s
>     @a_r_g_s
>   end
>
>   def d_u_c_k_c_a_l_l
>     begin
>       yield
>     rescue TypeError => e
>       self.send(e.message)
>       retry
>     end
>   end
>
>   def method_missing(aSym, *args)
>     # This will happen the first time
>     aSymStr = aSym.to_s
>     @a_r_g_s["#{aSymStr}"] = [ args.collect { |a| "#{a.class}" } ]
>     begin
>       d = %Q{
>         def self.#{aSymStr}(*args)
>           # This will happen the subsequent time
>           @a_r_g_s["#{aSymStr}"] } + %q{.concat [ args.collect { |a|
> "#{a.class}" } ]
>           self
>         end
>       }
>       instance_eval d
>     rescue SyntaxError
>       puts "TypeError induced SyntaxError! TypeError must return respond_to
> method!"
>       raise
>     end
>     self
>   end
>
> end
>
> # example
>
> class TypeTest
>   def ameth(x)
>     big4 x
>     #---
>     puts x.to_i
>     puts x.jump(4)
>     puts x.do_what_ever("Duck can take it!", /\w+/)
>     puts x.do_what_ever("Duck can take it!", /\w+/, 42)
>   end
> end
>
> t = TypeTest.new
>
> puts "\nDUCK QUACKS"
>
> dh = DuckHunter.new
> dh.d_u_c_k_c_a_l_l do
>   t.ameth(dh)
> end
>
> # show args
> puts "\nameth:"
> dh.a_r_g_s.each { |name, argpat| argpat.each { |args| puts "\t#{name}
> (#{args.join(',')})" } }
>
> # -----------
>
> On Saturday 22 November 2003 12:52 am, Greg McIntyre wrote:
> > "David Naseby" <david.naseby@eonesolutions.com.au> wrote:
> > > Below is a quick hack to do that. Needs work. Needs redirection of IO.
> > > But its kinda cute.. Has issues with side effects, of course, and
> > > printing crapola all over the place.
> >
> > Is this or something like it on the RAA? Perhaps a slightly more general
> > mechanism to proxy messages to the "real" object and call a
> > hook/callback?
>
> late could be added