Re: texinfo 6.0 texindex problem?

[Gavin Smith]

On 8 October 2015 at 20:06, Aharon Robbins <address@hidden> wrote:
> Hi.
>
> I added
>
> @tex
> \global\usebracesinindexestrue
> @end tex
>
> to gawktexi.in in the gawk dist and built a pdf with the tools from
> texinfo 6.0.  Something's weird.  First, there is no initial for \.
> Second, braces come out under backslash.
>
> Did I do something wrong?  Index files attached.
>
> Thanks,
>
> Arnold

It appears that the texinfo.tex version from Texinfo 6.0 is not the
one that's being used here, but one more recent. However, the version
of texindex being used likely is the one from Texinfo 6.0. If you used
the current development version of texindex (or possibly the texindex
from an earlier release than 6.0), then I expect the braces coming out
under backslash problem would be resolved.

The lack of initial for \ is expected. This is due to a change in
index sorting where backslash is ignored for the purposes of
generating a sort key, along with a few non-alphabetic characters. So
many manuals have indexed items starting with a backslash that are
better indexed under a letter following the backslash (an example from
Texinfo's manual is \mathopsup, better indexed under "M"). Admittedly,
sometimes a backslash on it's own is indexed (I see the gawk manual
has many occurrences of this), but this is likely the rarer case.
There is a new syntax for specifying an explicit sort key that was
introduced after the Texinfo 6.0 release. It looks like

@cindex @sortas{\ escape sequence} \ (backslash), escape sequence

Here "\ (backslash), escape sequence" is the text that will be output
in the index, and "\ escape sequence" is the sort key.