Re: local/typeset stupidity

[Nikolai Weibull <mailing-lists.zsh-users@rawuncut.elitemail.org>]

* Peter Stephenson <pws@csr.com> [Dec 20, 2004 13:00]:
> > func () { local s="..." }
> > 
> > then I don't expect zsh to respond with
> > 
> > func:local:1: not valid in this context: 100
> > 
> > right?

> There's something you're not telling us.  With the default zsh options
> the syntax you show is guaranteed to work.  My guess is something is
> causing what you show in "..." to be split into words.  Is there a
> "$@" inside it?  For example,

> func() { local s="$@" } func foo 100

Argh, man, I need to get used to hom $(...) works.  It looks like one
element, but its of course split in that position.

> s="..."

> is special syntax; it's recognised as a scalar assignment, so
> wordsplitting is implicitly turned off.  This differs from "local"
> which has the semantics of a normal builtin, almost (actually, there's
> special behaviour of ~'s and ='s at the start of the value).

> This is rather nasty.  People often expect assignments after "local"
> etc. to be the same as assignments on their own, but that syntax
> conflicts with the way the arguments of builtins, and any other
> commands, are handled.  There's no simple answer, but retaining
> builtin syntax is at least predictable and stops the already
> horrendous code for local variables from becoming any worse.  Any way
> round is a kludge of some sort.

This is what fooled me, yes.

> >  Even with
> > 
> > setopt typesetsilent # (how can't this be the default?)

> typesetsilent works around a different problem:

> func() { local s; local s; } func

> outputs

> s=''

> unless the option is turned on.  This came from the very early days of
> zsh.  It was mostly useful for examining the state of variables that
> already exist interactively; it's not obvious you would use it in a
> function.  It's annoying this is the default behaviour.  There may be
> a better way of suppressing the output in functions, but I'm not sure
> whose functions it would break.  Personally I'd be quite happy to have
> the effect of typesetsilent enforced inside functions.  A compromise
> would be to keep the non-silent behaviour only for "typeset" itself.

Yes, definitely.  It's weird where the language has dynamic binding, yet
"complains" about things like this.

Thanks for your help,
	nikolai


-- 
::: name: Nikolai Weibull    :: aliases: pcp / lone-star / aka :::
::: born: Chicago, IL USA    :: loc atm: Gothenburg, Sweden    :::
::: page: www.pcppopper.org  :: fun atm: gf,lps,ruby,lisp,war3 :::
main(){printf(&linux["\021%six\012\0"],(linux)["have"]+"fun"-97);}