Re: Block comments ala Ray

[Bart Schaefer <schaefer@brasslantern.com>]

On Fri, Feb 12, 2021 at 7:45 AM Stephane Chazelas <stephane@chazelas.org> wrote:
>
> 2021-02-12 07:30:23 -0800, Bart Schaefer:
> > On Thu, Feb 11, 2021 at 11:40 PM Stephane Chazelas
> > <stephane@chazelas.org> wrote:
> > >
> > > :||:<<'# some comment'
> >
> > That's exactly what the zsh-users discussion has been telling Ray he
> > should not do, because at some point it's not going to work the way he
> > expects.
> [...]
>
> How so?

What was said on zsh-users (not by me):

"Here-documents are not comments, despite your best efforts to abuse
them for that role."

"The construct you use has side-effects you've overlooked, which mean
your fashion of comments will backfire in a way that you don't see yet."

(Paraphrased) There are places where you might want comments but that
command syntax is not allowed, for example in the midst of "for ...
do".

> How would it be different from your !# .. #! ?

For one thing, the content of a here-document is "compiled" into the
wordcode of the script or function, even if the command referencing
that here-document is never going to execute.   True comments are
discarded during lexing.