From: Mark Hahn <mchahn@...>
Date: 2001-12-11T09:11:02+09:00
Subject: [ruby-talk:28157] Re: The benefits of dynamic typing?


That looks correct.  If String::to_s is fast (it should be since there is
nothing to do) then this is even simpler:

class String
    alias old_plus +
    def +(x)
        old_plus x.to_s
    end
end

But my point was the arguments being made against this feature fell into the
"protecting programmers from themselves" category which I have a big problem
with.

How does everyone else feel about "protecting programmers from themselves"?
At what point does a compiler switch from being helpful to being a pain?

I think this is the fundamental question behind this message thread.

-----Original Message-----
From: Harry Ohlsen [mailto:harryo@zip.com.au]
Sent: Monday, December 10, 2001 4:02 PM
To: ruby-talk ML; undisclosed-recipients:
Subject: [ruby-talk:28155] Re: The benefits of dynamic typing?


In article <CEENJIKJHPPGICBNAFMIGECADCAA.mchahn@facelink.com>, "Mark Hahn"
<mchahn@facelink.com> wrote:


> The reason I lost the argument was that they claimed it would cause
> hard-to-find bugs if someone meant: "1".to_int + 1.  They claimed it was
> ambiguous.  To me it is obvious that "1"+1 means a string and 1+"1"
> means an integer (because of message passing).

You can make this work the way you want (although, you'd have to stick
this code in a module and "require" it in all your code).  Note that I'm
not known for writing the simplest version of things, so someone else
will probably have to clean it up for me (and I've only done the 1 + "1"
case for Fixnum; it would probably have to be coded more generally to be
useful) ...

class String
    alias old_plus +

    def +(x)
        if x.type == String
            old_plus x
        else
            old_plus x.to_s
        end
    end
end


class Fixnum
    alias old_plus +

    def +(x)
        if x.type == String
            old_plus x.to_i
        else
            old_plus x
        end
    end
end

puts "1" + 1 # => "11"
puts 1 + "1" # => 2