ARGC (and other readonly specials) and "local"

ARGC (and other readonly specials) and "local"

[Bart Schaefer]

This is 4.0.1-pre-2:

zsh% ARGC=0
zsh: read-only variable: ARGC
zsh% argc () { echo $ARGC; local -i ARGC; ARGC=0; echo $ARGC }
zsh% argc a b c
3
3

So even though I can make it local and thereby not read-only, it still
behaves as if it were read-only.

This is of course what "local -h" is for.  However:

zsh% argc () { echo $ARGC; local -Z3 ARGC; ARGC=0; echo $ARGC }
zsh% argc a b c
argc:local: ARGC: can't change type of a special parameter

If I can't change any other attributes, why should I be able to change
readonly?

BTW, I found this interesting:

zsh% typeset -i2 ARGC
zsh% echo $ARGC
2#0

So *some* attributes can change, even of readonly parameters.

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

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net