From: Wesley J Landaker <wjl@...>
Date: 2003-12-05T07:40:11+09:00
Subject: Re: Generalized break?

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On Thursday 04 December 2003 3:13 pm, Hal Fulton wrote:
> I've sometimes wished for a "break" that would work in (almost) any
> context -- one that would do "the sensible thing" instead of just
> giving an error saying you can't do a break here.
>
> Two examples are:
>
> 1. A long string, possibly multiline/multi-statement, is being
> evaled. I want the capability to abort the eval.
>
> 2. I have a mild dislike for the idiom if $0 =3D=3D __FILE__ (lines) end
> -- because I always indent inside an if, and I don't want to indent,
> and I really just want to say:  break if $0 !=3D __FILE__

I actually would like that too, especially for #2, since it avoids lots=20
of nasty nesting for unit tests and such.

>
> In both these contexts, I initially tried exit. Of course, that
> doesn't work -- it exits the entire program. A "return" seems like
> the next choice, but that only makes sense within a method.

I think break makes sense here, and I'd use it if it were available.

> There's no proper way to do this kind of thing, as far as I can
> see.

Well, maybe not proper, but here is *a* way to do it. ;)

#!/usr/bin/ruby

puts "File loaded."

if $0 =3D=3D __FILE__ then puts <<-EOF ; end

# look, no indent, and we're not nested in an if! =3D)
puts "File called directly."

EOF



=2D-=20
Wesley J. Landaker - wjl@icecavern.net
OpenPGP FP: 4135 2A3B 4726 ACC5 9094  0097 F0A9 8A4C 4CD6 E3D2


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