Re: Sorting on compound keys?

[Andreas Röhler]

Am 26.05.2011 00:08, schrieb Tim Landscheidt:
> Andreas Röhler<andreas.roehler@easy-emacs.de>  wrote:
>
> > > sometimes I want to sort unified diffs of CSV files (sepa-
> > > rated by tabs (here: \t)):
>
> > > | +A 1\t1\tx
> > > | +A 1\t2\ty
> > > | +B 2\t3\tz
> > > | -A 1\t1\tx
> > > | -B 2\t2\ty
> > > | -B 2\t3\tz
>
> > > by the second column, then the first column, then "+" vs.
> > > "-". Unfortunately, it seems that sort-regexp-fields doesn't
> > > allow more than one match field as a key. sort-fields
> > > doesn't work either as it requires the fields to be sur-
> > > rounded by white space (no "+" vs. "-") and doesn't allow
> > > white space inside the fields.
>
> > >     Is there any function in vanilla Emacs (23.1.1) that I
> > > missed? I looked at pimping sort-regexp-fields, but it seems
> > > to me that sort-subr would have to be rewritten from scratch
> > > to achieve sorting on compound keys.
>
> > last time I looked into that feature was missing indeed.
> > However, didn't look for a need of re-write from the
> > scratch, just to extend to existing routine - ie. introduce
> > one or more levels of sorting.
>
> I remember our discussion in de.comp.editoren :-), but as I
> read sort-subr it is hard-coded that the sort key is one
> literal, continuous part of the buffer as sort-lists is a
> list of buffer positions.
>
> Tim


sort-subr takes functions to determine the fields to sort.

As for the functions as arguments, maybe have a look at
`ar-th-sort' in thingatpt-utils-base.el

https://code.launchpad.net/s-x-emacs-werkstatt/

Cheers,

Andreas