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[mkgmap-dev] Fix and augment sort definitions

From Gerd Petermann gpetermann_muenchen at hotmail.com on Tue Jan 4 09:50:41 GMT 2022

Hi Ticker,

I think you need option -g with svn log to see changes done in branches.

Anyhow, I think I made a mistake back then because I didn't think of devices which
are not configured to show a German keyboard (which has keys for äöü and ß).

You are probably right that the expands are better for this case and I don't
remember what problems I had with the ß. It is very likely that the open
collator strength questions are the better approach.

I test with a tile around my hometown Wildeshausen
55410043: 2447360,389120 to 2469888,407552
#       : 52.514648,8.349609 to 52.998047,8.745117

One problem that I found on the Oregon is the search for a
name that appears as a nearby city called "Voßberg"

This name doesn't appear in the Oregons basemap.
I created a map with --latin and --lower-case.
When I search for Voß it is not found. Same when I search
for Voßber. Only the search for the full name works.
Voss is also not found, but Vossberg works.

Without the patch, search for Voß returns Voßberg,
search for Vossberg does that also, which is quite confusing
for me.
My basemap shows
--------- Description ----------------------------------------------------------
00000035 | 41 53 43 49 49 20 53 6f | Description: ASCII Sort
0000003d | 72 74 00                |
--------- Character table header -----------------------------------------------
00000040 | 000000 | 5c 00                   | sub header len 92
00000042 | 000002 | 01 00                   | id1 1
00000044 | 000004 | 01 00                   | id2 1
00000046 | 000006 | e4 04                   | codepage 1252

Maybe I should repeat those tests with the mdr2 branch?


Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
Gesendet: Dienstag, 4. Januar 2022 09:40
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] Fix and augment sort definitions

Hi Gerd

Sorry - I hadn't noticed these changes. They don't show up with
$ svn log resources/sort/cp1252.txt or cp1254.txt

All the other mkgmap sort files have all the expansions possible
including the eszett and diphthongs if applicable.

The two non-mkgmap sort files (0000848.SRT/Turkey and
I00003A0.SRT/adriatic TOPO) have expand for "ß" and some of "Œ"... so I
presumed it was expected and reasonably supported.

In the binaries, the expand is expressed as a list of sortOrders
{primary,secondary,tertiary}. The secondary and tertiary are disrupted
and don't match ones from actual characters (in the case of "ß", the
two s's get different secondaries). So these double chars will sort
after the real char and only match with PRIMARY.

As there many unknowns about how to make --lower-case indexing work and
the setting, regarding collation strength, of the bit-flag indicating
same-name in some of the MDR sections, I feel that it is better to have
the all the expands.

However, if you are against this, I'll redo cp1252 without these
expansions. I'm not sure of the basis of having the diphthongs as
alternate secondaries of their first character and the eszett as a
unique character.


On Mon, 2022-01-03 at 11:44 +0100, Gerd Petermann wrote:
> Hi Ticker,
> see
> https://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=3948
> https://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=3949
> the sortResource.patch reverts these changes.
> In Mapsource the results are a bit better with your patch.
> I'll try again with my Oregon later.
> Gerd
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> https://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

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