[NTG-context] How to sort in Lua using locale?

[Mojca Miklavec]

Hello,

I would like to create a document using some functionality that is
pretty close to creating an index, but the built-in index creation
code doesn't suffice. My main question is: how do I sort strings using
the built-in sorting rules for the current language?

Here is an example with a table of names:

names = {
{first=Hans, last=Hagen},
{first=Hartmut, last=Henkel},
{first=Taco, last=Hoekwater},
{first=Caron, last=Haček}
{first=Ančka, last=Car}
{first=Ana, last=Car}
{first=Anita, last=Car}
{first=Matija, last=Čop}
}

and I want to print out the following:

\section{C}
\person{Car}{Ana}
\person{Car}{Ančka}
\person{Car}{Anita}

\section{Č}
\person{Čop}{Matija}

\section{H}
\person{Haček}{Caron}
\person{Hagen}{Hans}
\person{Henkel}{Hartmut}
\person{Hoekwater}{Taco}

The following code works for English and needs a fix to respect local
sorting rules. I would be grateful for any hint before reinventing the
wheel (the hint can also be a pointer to the right line of ConTeXt
source code that does the sorting; I was a bit lost in the code).

\mainlanguage[sl]
\setuphead[section][style=\bf,before=\blank,after=,number=no]
\def\person#1#2{\hbox{{\sc #1}, #2}}

\starttext

Code that needs fixing:

\startluacode

names = {
{first=Hans,last=Hagen},
{first=Hartmut, last=Henkel},
{first=Taco,last=Hoekwater},
{first=Caron,   last=Haček},
{first=Ančka,   last=Car},
{first=Ana, last=Car},
{first=Anita,   last=Car},
{first=Matija,  last=Čop},
}

-- this should sort with local sorting rules; how?
function sort_names(a,b)
if (a.last == b.last) then
return a.firstb.first
else
return a.lastb.last
end
end

-- this is extremely ugly and needs to be fixed
-- with some UTF-8 library
function first_letter(str)
if (string.byte(str,1)127) then
return string.sub(str,1,2)
else
return string.sub(str,1,1)
end
end

table.sort(names, sort_names)

for k,v in pairs(names) do
-- nested tables would also be an option; but are not required
if (k==1) or (k1 and (first_letter(names[k-1].last) ~=
first_letter(v.last))) then
tex.print(string.format('\\section{%s}', first_letter(v.last)))
end
tex.print(string.format('\\person{%s}{%s}', v.last, v.first))
end

\stopluacode

\crlf\crlf

Desired result:

\section{C}
\person{Car}{Ana}
\person{Car}{Ančka}
\person{Car}{Anita}

\section{Č}
\person{Čop}{Matija}

\section{H}
\person{Haček}{Caron}
\person{Hagen}{Hans}
\person{Henkel}{Hartmut}
\person{Hoekwater}{Taco}

\stoptext

Thanks a lot,
   Mojca
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Re: [NTG-context] How to sort in Lua using locale?

[Hans Hagen]

On 12-7-2010 12:30, Mojca Miklavec wrote:

Hello,

I would like to create a document using some functionality that is
pretty close to creating an index, but the built-in index creation
code doesn't suffice. My main question is: how do I sort strings using
the built-in sorting rules for the current language?


\startluacode
document.whatever =  { names = { } }

function document.whatever.sortnames()
local names = document.whatever.names
local split = sorters.splitters.utf
for i=1,#names do
local name = names[i]
name.split = {
split(name.last),
split(name.first),
}
end
sorters.sort(names, sorters.comparers.basic)
end

function document.whatever.flushnames()
local names = document.whatever.names
local previous = false
for i=1,#names do
local name = names[i]
local letter, current = sorters.firstofsplit(name)
if previous ~= current then
previous = current
context.section(letter)
end
context.person(name.last,name.first)
end
end

document.whatever.names = {
{ first = Hans,last = Hagen },
{ first = Hartmut, last = Henkel },
{ first = Taco,last = Hoekwater },
{ first = Caron,   last = Haček },
{ first = Ančka,   last = Car },
{ first = Ana, last = Car },
{ first = Anita,   last = Car },
{ first = Matija,  last = Čop },
}

sorters.setlanguage(sl)
document.whatever.sortnames()
document.whatever.flushnames()
\stopluacode

-
  Hans Hagen | PRAGMA ADE
  Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
 | www.pragma-pod.nl
-
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wiki : http://contextgarden.net
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