From: cjon@... (Cullen J O'neill)
Date: 2001-03-13T08:10:07+09:00
Subject: [ruby-talk:12533] Re: FEATURE REQUEST: 'my' local variables

Stephen White (spwhite@chariot.net.au) wrote:
: On Mon, 12 Mar 2001, W. Kent Starr wrote:

: > Howabout creating a "strict" local using a prefix in front of an alpha 
: > (excepting symbols like $) as in _var to mean LOCAL! LOCAL!! LOCCAL!!!
: > as in :
: > 
: > x = 5; loop { |y| x = 3; x * y }; puts x ->5
: > x = 5; loop { |y| _x = 3; _x * y }; puts x -> 3

: I think this is the best suggestion I've seen so far, though it needs
: to be better defined to cover this scenario:

:   x = 5; loop {|y| _x = x + 5; loop {|y| puts _x } }

: Does the _x carry over from the parent loop?

What about the reverse:

x = 5; loop { |y| x = 3; x * y }; puts x ->3
x = 5; loop { |y| _x = 3; _x * y }; puts x -> 5

This is just like normal code.

and

x = 5; loop {|y| _x = x + 5; loop {|y| puts _x } } -> 10

and

_x = 5; loop {|y| _x = x + 5; loop {|y| _x = 12 }; puts _x } ; puts _x

-> 10 5 (where the first puts will output 10 and the second 5)

_ at the beginning basically would mean that the variable will be
shadowed by default (in blocks anyway)


Cullen J O'Neill
--
cjon@engin.umich.edu