Re: Optimal way to defining of macros in Luacode in ConTeXt

[Hans Hagen <pragma@wxs.nl>]

On 13-7-2011 10:05, Jaroslav Hajtmar wrote:
> Hello all.
> It is GREAT! Thanx Hans and Wolfgang too. It is very instructive and
> inspiring for me...
> I was looking for something similar for a long time, but I have not
> found anything (not even in the CLD-MKIV and others ...). Finally, after
> yours reply to this email find something in the ctx-man.pdf from 1997
> year :-).
> But I have a few questions and comments on this subject:
>
> 1. Is there any possibility to do anything similar with counters,
> dimensions etc? I trying but without success.
> For example:
> context.newcount(mycounter) or context.newcounter(mycounter)
> context.mycounter=5 etc.

As currently we cannot define a counter at the tex end (using countdef) 
it would introduce too much complexitity to mimmick that now.

When you do:

context.newcount("name")

you should realize that this command is effectuated after the lua call, 
so if you want a counter also at the tex level you should define it at 
that end,

\newcount\name

> or it must be realized by classical way:
> context('\\newcount\\mycounter')
> context('\\mycounter=10')
> context('\\advance\\mycounter by5')
> context('\\the\\mycounter')

tex.count.name = 10
tex.count.name = tex.count.name + 5

if you never need the counter at the tex end, you can of course use a 
lua number instead.

> similary with \newdimen, \newif etc...

at some point we will have helpers for that

> 2. Any person interested in using context.setvalue{"Mymacro",somevalue)
> and context([[\def\MyMacro#1{#1}]]) syntaxes I have pointed out that the
> second syntax only operates when the command is given in a separate LUA
> file (ie file.lua) (ie not within an environment \startluacode -
> \stopluacode in classical TEX file!!!). Hans told me once that it is the
> individual categories of characters (backslash??) (if I remember
> correctly).
> First syntax works perfectly in LUA and TeX files too.

indeed, but if you already have the command and it's defined as 
unexpandable then you can use the [[ ]] method too

> Here I have a question. Why not comment out this case in TEX file?
>
> \startluacode
> -- context([[\def\macro#1{#1}]])
> \stopluacode
>
> I get error:
> ! Undefined control sequence.
> -- context([[\def \macro
> #1{#1}]])
> \dodostartluacode ...and \directlua \zerocount {#1
> }}
> l.25 \stopluacode
> ?
>
> That category characters again? Comment character -- works differently
> in TEX file, and otherwise in the LUA file?
> Ie. comment on the backslash?

indeed

> 3. Wolfgang write about using context command
>
> \convertnumber{R}{1400} and the corresponding syntax:
> context.convertnumber("R",1400) to roman converting.
> It is great, but I could not figure out how to use in combination with
> the above syntax (ie use case context.command) or find the appropriate
> conversion LUA function (I did not use a custom function).
> Is there any way to do something like that:
>
> context([[\def\Macro%s{Macro%s}]],context.convertnumber("R",1400),1400) ???
> ie. TEX command is used as a LuaTeX parameter?

context([[\def\Macro%s{Macro%s}]],converters.romannumeral(1400),1400)

Hans

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                                           Hans Hagen | PRAGMA ADE
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