Re: Radix tree for character conversion

Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Oct 7, 2016 at 6:46 AM, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
>> Ouch. We should find and document an authoritative source for all the
>> mappings we have...
>> 
>> I think the next steps here are:
>> 
>> 1. Find an authoritative source for all the existing mappings.
>> 2. Generate the radix tree files directly from the authoritative sources,
>> instead of the existing *.map files.
>> 3. Completely replace the existing binary-search code with this.

> It might be best to convert using the existing map files, and then
> update the mappings later.  Otherwise, when things break, you won't
> know what to blame.

I think I went through this exercise last year or so, and updated the
notes about the authoritative sources where I was able to find one.
In the remaining cases, I believe that the maps have been intentionally
tweaked and we should be cautious about undoing that.  Tatsuo-san might
remember more about why they are the way they are.
        regards, tom lane