From: Jacob Burkhart <igotimac@...>
Date: 2007-05-31T21:17:35+09:00
Subject: Re: Introducing the "it" keyword

Would a let or with construct be fast enough and memory efficient
enough for those concerned about such things?

def with(args*)
    yield args
end

with( v + 1 ) do |it|
    return it if it < 10
end

If this isn't fast enough or memory-efficient enough, then I would
suggest we find a way to make the interpreter recognize or optimize
such cases.

Perhaps "with" could be provided by the language by default, and then
we could support this line as syntactic sugar:

return it if with(v+1) < 10

or maybe:
return it if with_it(v+1) < 10

The interpreter would have to recognize and transform this into the
equivalent with ... do ... end

Or maybe we can go really crazy with the syntax, and support any name
for the 'tmp' variable (and any number of temp variables) with the
knowledge that if we use this syntax to assign them, the interpreter
will know to transform and garbage collect appropriately.

return it if with:it(v+1) < 10

return a if with:a(v+1) < 10

return a,b if ( with:a(v+1) + with:b(x*y) ) < 10