From: tho_mica_l <micathom@...>
Date: 2008-02-08T14:30:02+09:00
Subject: Re: Ruby type-safe? Ruby strongly/weakly typed? Ruby pitfalls?

> Thought it was interesting.  So you can easily add type checking to
> your functions if you desire to do so.

Well, there are various way to add something in this line to the
language. E.g., one could easily do something like this:


    class Class

        def let(value)
            unless self === value
                raise TypeError, 'expected %s but got %s' %
[self.name, value.class.name]
            end
            value
        end

    end

    irb(main)> String.let a = 1
    TypeError: expected String but got Fixnum

    irb(main)> String.let a = "foo"
    => "foo"

But the idea of type definitions and argument checks would of course
be
to give the compiler/interpreter a chance to perform some sanity
checks
at load/compile time. For this to happen, ruby would have to
understand
these definitions though and try to make some sense out of them. Now
I
know the counter-arguments since this isn't the first time this was
discussed. I nevertheless wish that ruby had some sense for
types/interfaces and from time to time I take the freedom to write
this.

Thomas.