From: ts <decoux@...>
Date: 2004-09-03T20:11:36+09:00
Subject: Re: Not just $SAFE, but damn $SAFE

>>>>> "F" == Florian Gross <flgr@ccan.de> writes:

F> Because sometimes the user wants to do a non-stupid, but still 
F> unexpected thing and then flexibility is good. But I think it would 
F> maybe be a good idea to allow white lists via an option to the safe()-call.

 and where is the problem ?

 There are 2 cases :

  * some classes are safe, because you can safely use a method to create an
    object.

    For example Symbol, NilClass, TrueClass, FalseClass, Fixnum, Bignum,
    Float, String, Exception, Regexp, Time, Range, Array, Hash

    your module can handle these classes

  * for other classes, define a protocol

    - when you enter in #safe store in an array, all classes which are not
      tainted (test it with Kernel#tainted?) and which define the method
      ::secure_it 

    - when the class of the result respond to this method, call it with the
      result of #eval

       kl.secure_it(obj)

      now this is the responsibilty to the user to make the "right" thing
      and at least it will not be the fault of *your* module if the user
      has a problem.


 It's evident that all this must be done at $SAFE >=4


Guy Decoux