Re: issorted & sortrows

[John W. Eaton]

On 12-Feb-2009, dbateman wrote:

| Jaroslav Hajek-2 wrote:
|
| > I think these are used for sorting cell arrays.
| 
| I confirm that they are used to sort cell string arrays

OK, I checked in the following change:

  http://hg.savannah.gnu.org/hgweb/octave/rev/a669df7beb73

(sorry about the useless hg log message).  This change restricts
sorting on cell arrays to cell arrays of strings only, by implementing
octave_cell::sort and octave_cell::sortrows_idx methods that ensure
that the cell array contains only strings, and then converts the array
of octave_value objects to an array of std::string objects before
doing the sort, then creates a new .  It might be good to have a way
to avoid doing the conversion if the array is already sorted, but I
don't see a way to do that since the is_sorted functions always seem
to examine the values.  Would it be worth caching the sort mode in the
Array?  When creating a cell from an Array<std::string> object, we
could copy the sort mode as well, then the octave_cell::sort function
could skip the sort without having to first convert the
Array<octave_value> object to an Array<std::string> object.

Does that make sense?  Does it seem worth the effort?

jwe