guile-user
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Gurus? Care to re-explain the absense of gh_set_x() for me?


From: Rob Browning
Subject: Re: Gurus? Care to re-explain the absense of gh_set_x() for me?
Date: 16 Jul 2001 07:50:00 -0500
User-agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.7

Miroslav Silovic <address@hidden> writes:

> > you'd get 9 printed as expected, but if you had:
> > 
> >   (define foo 4)
> >   $foo = 5;
> >   (define foo 9)
> >   print "$foo\n";
> > 
> > I'm not sure what you'd get.
> 
> By r5rs, top-level define of a defined value is the same as set!.

Right, but here, according to the solution I was suggesting, $foo = 1
would be manipulating a "variable cell" (a la libguile/variable.*),
something that isn't part of r5rs, so it's semantics aren't defined.

Basically what I was worried about was if there was somehow another
level of indirection (or an "always lookup mechanism") involved on the
Guile side so that define could create a new variable cell for the
second define and (re)bind it to foo without breaking all the other
references to foo.  Unlikely, I admit, but I didn't know...

My guess is that you're right, though.

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
GPG=1C58 8B2C FB5E 3F64 EA5C  64AE 78FE E5FE F0CB A0AD



reply via email to

[Prev in Thread] Current Thread [Next in Thread]