hello, excuse my bad english
your sample code that you write what it should produce you propose for the
future so ?
it doesnt make me much sense that unset -v assoc[$key] gives syntax error
or so..
also about the assoc_expand_once i dont understand
cant it be as written, expand_once ( maybe _at_beginning_only )
set unset -v assoc[$key] would expand key as alike the first argument of
[[ comparision
to a string $( echo foo ) .. no more further .. .. and work out .. .. ?
i dont understand im sorry
On Tue, Mar 16, 2021 at 7:03 AM Lawrence Velázquez <v...@larryv.me> wrote:
> > On Mar 15, 2021, at 9:03 PM, Léa Gris <lea.g...@noiraude.net> wrote:
> >
> > Please excuse my profanity of mentioning zsh in this list, but I really
> think features and behavior convergence can benefit end users in multiple
> ways, especially when expanding beyond the POSIX sh scope.
> >
> > What direction has taken zsh with expanding associative array indexes?
>
> Broadly speaking, zsh treats subscript expressions as if they are
> double-quoted, but it does not perform arithmetic expansion on associative
> array indices (although subscript expressions must still adhere to related
> parsing rules).
>
> % zsh --version; echo
> zsh 5.8 (x86_64-apple-darwin18.7.0)
>
> % cat /tmp/demo1
> # Chet's example modified to highlight certain behaviors
> foo() {
> echo uname >&2
> echo +1
> }
>
> declare -A assoc
> key='x$(foo)]=1,b[1$(foo)'
>
> assoc[$key]=0
> declare -p assoc b
>
> % zsh -f /tmp/demo1
> /tmp/demo1:declare:10: no such variable: b
> typeset -A assoc=( ['x$(foo)]=1,b[1$(foo)']=0 )
>
> However, it does perform multiple expansions in arithmetic contexts.
>
> % cat /tmp/demo2
> # Chet's example modified to highlight certain behaviors
> foo() {
> echo uname >&2
> echo +1
> }
>
> declare -A assoc
> key='x$(foo)]=1,b[1$(foo)'
>
> (( assoc[$key]++ ))
> declare -p assoc b
>
> % zsh -f /tmp/demo2
> uname
> uname
> typeset -A assoc=( [x+1]=1 )
> typeset -a b=( '' 1 )
>
> Furthermore, "as if they are double-quoted" is rather literal. (Special
> handling allows the use of a["foo"] instead of a[\"foo\"].)
>
> % cat /tmp/demo3
> declare -A a
> key='$(echo foo)'
> a[$key]=1
> a['$key']=2
> a["foo"]=3
>
> declare -p a
>
> % zsh -f /tmp/demo3
> typeset -A a=( ['"foo"']=3 ['$(echo foo)']=1 [\''$(echo foo)'\']=2
> )
>
> If we tweak the preamble to create the intended array (and disable NOMATCH
> to treat failed filename generation as bash does), the unset commands work
> the same as in Chet's proposal.
>
> % cat /tmp/demo4
> declare -A a
> key='$(echo foo)'
> a[$key]=1
> a[\$key]=2
> a[foo]=3
>
> # Avoid Chet's intentional error because it's difficult to get zsh
> to
> # imitate it faithfully.
> #unset -v a[$key]
> declare -p a
>
> # unsets element with key $key
> unset -v a['$key']
> declare -p a
>
> # unsets element with key $(echo foo)
> unset -v a["$key"]
> declare -p a
>
> # unsets element with key foo
> eval unset -v a\["$key"\]
> declare -p a
>
> % zsh -f +o NOMATCH /tmp/demo4
> typeset -A a=( ['$(echo foo)']=1 ['$key']=2 [foo]=3 )
> typeset -A a=( ['$(echo foo)']=1 [foo]=3 )
> typeset -A a=( [foo]=3 )
> typeset -A a=( )
>
> vq
>
