From: David Flanagan <david@...>
Date: 2007-09-11T05:19:44+09:00
Subject: integer range literals in conditionals with -e option

Hi,

Here's a question for experts whose memories go back to vrsion 1.6 or 
before...

I know that you can use regexp literals in conditionals with the -e 
option.  There is an implicit comparison to $_ in this case. I gather 
that this used to work everywhere (in 1.6?) but that in 1.8 it only 
works with -e.

The Pickaxe asserts that range literals can also be used in conditionals 
with -e and that there is an implicit test against $. (current line 
number).  This would allow awk-like scripts to print a set of line 
numbers:  ruby -n -e 'print if 1..5'.

There appears to be code to implement this in parse.y, but I can't make 
it work.  (See the range_op method, which appears to insert a == 
comparison with $. Which is surprising, since it ought to insert a === 
comparison, I'd think.  The code never seems to be triggered, though.)

Anyone know what the history and current status of this is?  Is the code 
in parse.y vestigal, or is  a regresson that this feature stopped 
working in 1.8?

	David