help-script(){ "${EDITOR:?vi}" "$(which "$1")"; }
help-script(){ "${EDITOR:?vi}" "$(which "$1")"; }
> If a word begins with an unquoted `=' and the EQUALS option is set, the remainder of the word is taken as the name of a command. If a command exists by that name, the word is replaced by the full pathname of the command.
To edit the source of `myscript` I can then use
vim =myscript