El dom, 23 de may. de 2021 a la(s) 04:51, Hans Hagen (j.hagen@xs4all.nl)
escribió:

> On 5/22/2021 11:34 PM, Jairo A. del Rio wrote:
> > Hi. Is \thewithproperty documented elsewhere? Is this a new primitive?
> > It looks interesting.
> In the case of the \sin trick particular case \let\computer\the would
> also work; i added the \thewithproperty<number> feature just because i
> expect that users can come up with variants (like \drawme\sin ...) which
> then would adapt behaviour (via \dowithproperty2).
>

Having flags for computing and drawing would be awesome. I think it would
nicely extend ConTeXt's drawing features...

So, indeed it's a new primitive but (for now) only used with these lua
> hacks. Actually it's no big deal to reimplement \thewithoutunit<dim> as
>

So, is this Lua-specific?

   \thewithoutunit{\dowithproperty1\the}
>
> and then
>
>    \thewithcmunit{\dowithproperty2\the}
>
> to serialize the dimension in cm but normally i need to "wonder for a
> while if it makes sense".
>
> Btw, adding primitives (related to the token related bits and pieces of
> the engine) only makes sense if the gain is in
>
> -- avoiding clumsy code: although that can hurt someones pride and joy
> over a nice and complex macro doing the same ... don't worry, i threw
> away plenty of code by now
>
> -- significant performance gain: which is seldom the case (there really
> is not much to gain, at least not in context which is rather optimized
> already)
>
> -- giving way less noise in tracing: which for me is a good reason
> (tracing changed a bit anyway)
>
> -- not adding much code to the engine or the need to refactor: although
> for some luametatex extensions some internals had to change fundamentally
>
> a good example is the extended macro argument handling: less clumsy tex
> code, a bit of performance gain and easier full expansion, way less
> tracing, but it violates the last argument because it did lead to some
> refactoring (i also had to make sure the extra overhead didn't slow down
> macro definitions and expansion)
>
> Hans
>
>
> -----------------------------------------------------------------
>                                            Hans Hagen | PRAGMA ADE
>                Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
>         tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
> -----------------------------------------------------------------
>

I did the following and I have two questions:

1. What if I want to have more than one property? Say \plusone for
computation and \plustwo for drawing.

2. What does 'usage="value"' mean in the implement function (looks new, but
I'm prolly wrong)?

\permanent\protected\def\drawme{\thewithproperty\plussix} %better than 666

\startluacode

local interfaces = interfaces

local implement = interfaces.implement

local context = context


local drawme_code = 6


local drawing = [==[

draw fullcircle scaled 10mm;

draw fullcircle shifted up scaled 5mm;

draw fulltriangle shifted (up+1/2right) scaled 5mm;

]==]


local function chicken(value)

if value == "value" or value == drawme_code then

context.metafun.start()

context.metafun(drawing);

context.metafun.stop()

--elseif then ...

else

context("Chicken!")

end

end


implement{

name = "chicken",

public = true,

usage = "value", --What does it do?

overload = true,

actions = chicken

}

\stopluacode

\starttext\chicken\ and \drawme\chicken\stoptext

Thank you in advance.

Jairo