Static variables?

Static variables?

[Johan Sundström]

Is it possible to use c-style "static" variables in my functions, or do I
have to stick to global ones? My precmd function doesn't get too happy when
its variables are tampered with, and it's quite slow enough as it is without
sanitytests. Having some variables accessable only from a certain function
(precmd in this case) would help a lot and unclutter the huge list of global
variables a bit, while at it.

If it's possible, how is it done?

/Johan Sundström

Re: Static variables?

[Bart Schaefer]

On Jun 14,  6:55am, =?iso-8859-1?Q?Johan_Sundstr=F6m?= wrote:
} Subject: Static variables?
}
} Is it possible to use c-style "static" variables in my functions, or do I
} have to stick to global ones?

The only "persistent" variable namespace is the global one.

That said, there may be a way to get the effect you want, because the
"local" namespace has dynamic scope.  Here's how:

First, rename your precmd as precmd_body.

Next, create a function precmd_setup which assigns values to the variables
you wish to make static.

Now create a new precmd which does the following:
- Declares "local" all the variables that are assigned in precmd_setup
- Executes precmd_setup (this assigns to the locals of precmd)
- Executes precmd_body (this references the locals of precmd)
- Redefines precmd_setup to assign the new values of the locals to
  the appropriate names, e.g. eval function precmd_setup \{ ... \}

Finally, be sure that none of the affected variables is declared local
in precmd_body (so it will inherit the locals from precmd).

The tricky bit is "redefines precmd_setup."  Depending on the values of
the variables in question, it may be difficult to generate on the fly a
new definition that performs the correct assignments.  Just how ugly are
the contents of the variables you're trying to preserve?

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com