From: "Hal E. Fulton" <hal9000@...>
Date: 2001-11-07T06:45:28+09:00
Subject: [ruby-talk:24469] Re: Range in Hash array?

----- Original Message ----- 
From: <puzzled186@hotmail.com>
Newsgroups: comp.lang.ruby
To: ruby-talk ML <ruby-talk@ruby-lang.org>; <undisclosed-recipients: ;>
Sent: Tuesday, November 06, 2001 3:26 PM
Subject: [ruby-talk:24456] Range in Hash array?


> I'd like to be able to do something like:
> {1..100=>"a",101..300=>"c", 500..1000=>"r"}
> 
> The syntax accepts it, but it doesn't behave the way I'd like (always
> comes up nil).
> 
> Anyway to pull this off (currently using a case statement).

I think the basic problem is that Ruby is doing exactly what
you tell it, rather than what you want. Don't you hate computers
for that?

A Range is itself an object. When you use it as a hash key, you
are associating the range itself with the given value... NOT each
item of the range with the given value.

So your hash above has only three keys, not 801 as I think you 
want.

You *could* create a hash of 801 elements easily this way:

h = {}
1..100.each {|x| h[x] = "a" }
101..300.each {|x| h[x] = "c" }
500..1000.each {|x| h[x] = "r" }

There are probably more elegant ways, though nothing comes
to mind... unless you wanted to just hide your case statement
inside a method (essentially a function returning the value 
based on the key). This would save a little memory but would
slow downyour runtime a little.

Hal