From: Michael Campbell <michael_s_campbell@...>
Date: 2003-07-17T23:57:24+09:00
Subject: Re: What's the point?

> I've known for some time that methods can be defined inside
> methods, but I am still wondering what's the point.
>
>   def fred
>     def x
>       puts "x"
>     end
>     x
>   end
>
>   fred
>   x
>
> produces
> x
> x
>
> Why would any sane person do such a thing? :)


I can only remember ever seeing this in Pascal (not that I have a wide
language experience base).

I can imagine the use for such a construct is similar to "private" methods
in a class (in a Java context).  You want abstract some procedure or
algorithm, but limit its visibility.  In the above case, 'x' is only known
to 'fred'.  If fred was doing a lot of repetitious stuff that wasn't
relevant outside fred, it might make sense to abstract the
repetitious/common stuff into 'x'.

I remember wishing for this sort of thing in C, where I didn't want to
clutter the 'global namespace' with my utility functions that were only
relevant within another function.  Maybe that was poor design on my part.