zsh has `= expansion`: > 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

zsh has `= expansion`: > 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