[NTG-context] consistent index entries

[Wolfgang Schuster]

Henning Hraban Ramm schrieb am 01.08.2020 um 20:49:
> 
> 
>> Am 01.08.2020 um 13:22 schrieb Henning Hraban Ramm <texml at fiee.net>:
>>
>> Hi,
>>
>> besides the CG journal I’m working on a scientific biography with huge person and locality indexes (named Person and Locality for the examples).
>>
>> In many cases, the author wants additional information in the index, e.g.
>>
>> \Locality{Altona (Hamburg)}
>> \Locality{Breslau (pol. Wrocław)}
>> or
>> \Person{Arends, Katharina (née Schoemaker)}
>> \Person{Wilhelm II. (Kaiser)}
>>
>> Now, I need that consistent and I don’t want to type these complicated entries every time.
>>
>> I’m looking for a good way to handle this – maybe a lookup table in Lua, so that
>> \LookupPerson{Willy II}
>> would call a Lua function that returns
>> \Person{Wilhelm II. (Kaiser)}
>> ?
>>
>> Or is there already something in place that I overlooked, like
>> \OverwriteIndexEntry{Hraban}{Ramm, Henning Hraban}
>> ?
> 
> I came up with:
> 
> \startluacode
> user.Lookups = {
>    ["Albano"] = "Albano (Provinz Rom)",
>    ["Altona"] = "Altona (Hamburg)",
>    ["Aurich"] = "Aurich (Ostfriesland)"
> }
> 
> function user.Lookup(Name)
>    local Res = user.Lookups[Name]
>    if Res then
>      return context(Res)
>    else
>      return context(Name)
>    end
> end
> \stopluacode
> 
> \def\Ort#1{\index{\ctxlua{user.Lookup("#1")}}}

You have to expand the \index argument:

\define[1]\Ort{\expanded{\index{...}}}

> \starttext
> 
> \Ort{Albano}
> \Ort{Altona}
> \Ort{Aurich}
> \strut\page
> 
> \placeindex
> 
> \stoptext
> 
> 
> The lookup works so far, but all the entries get sorted unter C (because of \ctxlua).
> 
> I remember I had the same problem with other macros (like \index{\emph{bla}}), but can’t find a solution in my usual sources.

When you use formatting commands etc. you have to use the optional 
argument for sorting.

You can avoid a few problems when you move the \index command to Lua and 
use context.index or you use a pure TeX solution.

%%%% begin lua example
\startluacode

userdata = userdata or { }

userdata.lookup = {
     ["Albano"] = "Albano (Provinz Rom)",
  -- ["Altona"] = "Altona (Hamburg)",
     ["Aurich"] = "Aurich (Ostfriesland)"
}

function userdata.index(name)
     local indexentry = userdata.lookup[name] or name
     context.index(indexentry)
end
\stopluacode

\define[1]\Ort{\ctxlua{userdata.index("#1")}}

\starttext

\Ort{Albano}
\Ort{Altona}
\Ort{Aurich}
\dontleavehmode\page

\placeindex

\stoptext
%%%% end lua example

%%%% begin tex example
\setvariables
   [index]
   [Albano={Albano (Provinz Rom)},
   %Altona={Altona (Hamburg)},
    Aurich={Aurich (Ostfriesland)}]

\define[1]\Ort
   {\doifelsevariable{index}{#1}
      {\expanded{\index{\getvariable{index}{#1}}}}
      {\index{#1}}}

\starttext

\Ort{Albano}
\Ort{Altona}
\Ort{Aurich}
\dontleavehmode\page

\placeindex

\stoptext
%%%% end tex example

Wolfgang