aopts-aset.sh

#!/bin/bash

aopts() { env - sh -s -- "$@"
} <<OPTCASE 3<<\OPTSCRIPT
acase() case "\$a" in $(fmt='
        (%s) f=%s; aset "?$(($f)):";;\n'
        for a do case "$a" in (--) break;;
        (--*[!_[:alnum:]]*) continue;;
        (--*) printf "$fmt" "$a" "${a#--}";;
        esac;done;printf "$fmt" '--*' ignored)
        (*) aset "" "\$a";;esac
shift "$((SHIFT$$))"; f=ignored; exec <&3 
OPTCASE
aset()  {  alias "$f=$(($f${1:-=$(($f))+}1))"
        [ -n "${2+?}" ] && alias "${f}_$(($f))=$2"; }
for a do acase; done; alias
#END
OPTSCRIPT