Re: [PATCH] test defs: add subroutine for input unindenting

[Ralf Wildenhues]

Hi Peter,

* Peter Rosin wrote on Sat, Feb 19, 2011 at 12:28:53AM CET:
> unindent ()
> {
>   sed '
>     /^$/b                   # Nothing to do for empty lines, next line please.
>     x                       # Get x<indent> into pattern space.
>     /^$/{                   # No prior x<indent>, go prepare it.
>       g                     # Copy this 1st non-blank line into pattern space.
>       s/^\([  ]*\).*/x\1/ # Prepare x<indent> in pattern space.

tab before space, please; or even better, use ...'"$tab"'...

>     }                       # Now: x<indent> in pattern and <line> in hold.
>     G                       # Build x<indent>\n<line> in pattern space, and
>     h                       # duplicate it into hold space.
>     s/\n.*$//               # Restore x<indent> in pattern space, and
>     x                       # exchange with the above duplicate in hold space.
>     s/^x\(.*\)\n\1//        # Remove leading <indent> from <line>.
>     s/^.*\n//'              # Restore <line> when there's no leading <indent>.
> }

I kinda like this.  It will be unintelligible without the comments,
however.  gnulib-tool has a sed comment removal, search for
$sed_comments.  What I wouldn't like is invoking an extra sed in each
test startup just to remove comments from a helper function, that will
noticeably slow down things (it could be removed at config.status
time?); OTOH, this function will be faster than our current unindent.

And I'll defer to Stefano's preference for or against complex code in
the testsuite.

Thanks,
Ralf