From: Brian Candler <B.Candler@...>
Date: 2003-02-21T07:47:11+09:00
Subject: Re: Lexical scope and closures

On Mon, Feb 17, 2003 at 12:05:01AM +0900, Tom Sawyer wrote:
> On Sunday 16 February 2003 06:06 am, dblack@candle.superlink.net wrote:
> > As one of the two or three people in the world who think that Ruby's
> > scoping rules are actually fine, I have to say that after all this
> > debate, people had better use whatever the new thing is, whether it's
> > necessary or not!  :-)
> 
> honestly, i probably have to agree. the more i think about it the more i see 
> that the way it is might be best after all.
> 
> > And I suspect people will, which means that if we have "local {}" or
> > "let x = ", we're going to see *lots* of them.
> 
> good point.

Just a random thought which occurred to me:

Suppose Ruby did introduce a declaration for local variables as discussed,
say 'let x=' for the sake of argument.

It has already been asked what happens if you used this outside a block.

Suppose you made 'let x=' the _only_ way to get a local variable? And
without it, 'x=' defaults to a method call, self.x= ?

It seems to me that a number of inconsistencies would vanish: 'x' always
refers to the object method 'x' or 'x=', unless you have previously
introduced it as a local variable with 'let x='. And then inside blocks, x
would continue to be bound to the same method or variable, unless you
introduce a new variable with another 'let x='.

Declarations for local variables would be clunky, same as Perl's "my". You'd
have to remember to use them, and take care when reordering lines that only
the first assignment of a variable said "let" (same as Perl). And there's
very little chance of backwards compatibility. But it would be very logical
and consistent :-)

But it's also not Ruby...

Regards,

Brian.