Re: [PATCH 1/2] <<# indent-stripping heredoc

[Dennis Williamson]

On Fri, Jul 14, 2023, 3:44 AM Grisha Levit <grishalevit@gmail.com> wrote:

> On Fri, Jul 14, 2023 at 3:44 AM Martin D Kealey <martin@kurahaupo.gen.nz>
> wrote:
> >
> > On the whole I think this is great, and thankyou for working up the
> patch, but I would like to offer some comments and suggestions:
>
> Thanks for looking at it, feedback very much appreciated.
>
> > One option that some other languages use is to find the terminator, and
> then use its indentation as the pattern to remove from the content lines.
> The problem of course is that it would take a double run over the content,
> but the benefit is that there'd only be one in-band signaling line instead
> of two.
>
> I agree, this would be useful functionality, would be interested in
> seeing your implementation.
>
> > Secondly, the battle for 8-space tabs has been well and truly lost at
> this point, so hard-coding that constant feels like it's likely to be a
> source of errors.
> >
> > In order to be tab-agnostic, I can see two reasonable options:
> > 1. remove only an exact match for the sequence of whitespace characters
> that occurs in the indicator line
>
> I think a problem with this is that a coding style using mixed
> tabs/spaces (such as the bash source..) would have
>
>         foo
>       EOF
>
> saved as:
>
> [tab]foo
> [spc][spc][spc][spc][spc][spc]EOF
>
>
> so I don't think it's feasible to record the indent level as a fixed
> tab/space mix if we are to allow indentation deeper into the heredoc
> using the document's native style, at least not without ending up back
> at the problem of needing to pick a tab stop width to use.
>
> Personally, I don't use this indentation style (but don't wish to
> precipitate an argument everyone is surely tired of) so I don't have
> much of an opinion on what would be useful here.  One slight point in
> favor of keeping the 8-space wide tab approach is that this is how
> readline renders literal tabs as well.
>


Would a declared spaces-per-level indent amount be useful? Something like
<<4# that would be the script writer's responsibility to conform to since
they set it. This might be in addition to the already proposed <<#.

>