From: Gavin Sinclair <gsinclair@...>
Date: 2004-10-01T10:59:30+09:00
Subject: Re: Range syntax theory

Zach wrote:
> This has been a very fun discussion. I'll shut up now unless anyone
> comes up with good reasoning for '..' and '...' or until Matz speaks. I
> think everyone knows where I stand.

I'll try to come up with a good reasoning.  Pretend I'm designing a language.

x..y is known to programmers of some other languages as representing a
"range"  (i.e. not necessarily what we'd call a Range, but something close
to the concept).  I decide that this concept will have its own
representation as a Range object.  So:

  2..6        # -> Range object

So far so good.  And familiar to some, but by no means all, programmers of
other languages.

Now I decide, for the good reasons put forth by others, that end-exlusive
ranges are useful enough to be treated explicitly as well.  I go hunting
for a way to represent them, and settle on

  2...6       # -> Range object

I find something visually appealing about it, don't agonise over it too
much, and there you go -- it's in the language.

Speaking as a Ruby programmer again, I personally find nothing whatsoever
confusing about the literal range notation, inclusive or exclusive.  And I
dislike the thought of reversing the notations; not based on precedent and
not wanting to change things, but based an aesthetics.  And trying to
explain why is like trying to explain appreciation for a poem.

Cheers,
Gavin