From: dblack@...
Date: 2006-07-29T20:53:56+09:00
Subject: Re: Wild ideas: Finding a missing 'end'

Hi --

On Sat, 29 Jul 2006, N Okia wrote:

> Yes, it has been considered. Unfortunately allowing the
> interpreter/compiler figure this out only works in the extremely
> simple case
>
> Consider:
>
> a=[1,2,3]
> for i in a
> begin
> if i > 1
>   x = 3*i
> end
> end
> puts x
>
> Obviously there is a missing end statement. However, where we put it
> makes a big difference. If we put it before the puts x, we get a very
> different output then if we put it after puts x. This is a simple
> example as well, even more complex examples will show that it gets
> very dangerous to let the interpreter figure out what you meant.
>
> Using indentation is dangerous, because indentation doesn't mean
> anything in ruby normally, and trying to figure out the right thing
> would mean that we start having to be careful with indentation levels,
> and code works in strange ways because we don't know ruby is 'helping'
> us out. It can make for very hard to find bugs.

But surely just a warning can't be harmful, even if it mentions what
turns out to be the wrong line -- ?


David

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