On 5/21/2021 4:37 PM, Aditya Mahajan wrote:

On Fri, 21 May 2021, Hans Hagen wrote:

...

I uploaded an lmtx update (only m-mathfun added).

Attached a short description of this (windy stormy friday afternoon) math experiment. The question is, what similar features using this trickery come to mind.

Personally, I can see occasionally making use of this instead of \ctxlua{myfunction(args)}. There is a similar library called pgfmath which is part of the tikz package, which is used quite heavily by the pgfplots package but also appears to be popular for other purposes:

https://tex.stackexchange.com/questions/tagged/pgfmath?tab=Votes I guessed right that you would be the first to to react! Anyway, I suppose that you come up with additional demands like:

\permanent\protected\def\randomized{\thewithproperty\plustwo} so that we can do: $ \sin(x) = \randomized\sin{2pi} $ which i'm sure you can figure out by looking at the source. 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 -----------------------------------------------------------------

On 5/21/2021 5:24 PM, Otared Kavian wrote:

Hi Hans,

Thanks for the new features you have introduced in the module mathfun. Actually I have been using commands such as the one mentioned by Aditya, \ctxlua{myfunction(args)} but for the formatting of the output, that is when one wants only 3 or four decimal digits, that approach is not very handy. So I will use the new feature and I’ll put it on the wiki once I have a few interesting examples. By the way, what does

\complexexpr{123 + new(456,789)} complex numbers, so (re=123,im=0) + (re=456,im=789)

this uses the xcomplex library that is in lmtx, while ecimal uses the xdecimal library for decimal precision(as in metapost decimal mode) 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 -----------------------------------------------------------------

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

...

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

On 5/22/2021 11:34 PM, Jairo A. del Rio wrote: 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

Thank you a lot for the explanation! It makes more sense now and definitively is something very promising to play with. Wrt the module itself, is it possible to consider language-dependent labels? I noticed "\sin" is "sin" when it should be "sen" once the module is loaded. Jairo El dom, 23 de may. de 2021 a la(s) 09:35, Hans Hagen (j.hagen@xs4all.nl) escribió:

On 5/23/2021 3:45 PM, Jairo A. del Rio wrote:

...

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

it relates to teh way tex sees things ... thihnk of

\dimen0=10pt

where \dimen expects a number, optional equal and value

while

\the\dimen0

the '\the' expects all kind of things, with '\dimen' being one of then in which case its value is serialized

in order to implement 'new primitives' using lua (like some that need to be implemented for compatibility reasons due to the backend differences) we need to be able to distinguish between setting and getting a value

so in that sense it's indeed lua specific: a specific class of lua functions knows if it's triggered by serialization

and that is what we 'kind of' abuse here and also why i did add this additional 'pseudo prefix' so that we ca ndo more clever things if we want to

...

\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)

...

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.

you can do that but keep in mind that \compute is then an 'official' context one (bound to 1) and any other number can conflict with other context numbers in the future, so best start at 1000 or so for private ones

...

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

indeed, it is already there for a while and it lets the function definition follow a different route ... basically one that can follow \the; I suppose that I can also make 'property' a valid usage (alias)

(btw often features like this are described in articles or wrapups inm documents in the distribution or even mentioned here but as usual with tex these things only make sense trigger usage when one really needs it)

...

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

or 31415 to fit in the tex numbering

...

\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

no need to check for "value" unless you also want:

\the\chicken

...

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 indeed an example of usage, and as with the mathfun, it saves a ton of macros like \drawchicken and so

so now you next challenge is to pass arguments so here a next phase

\permanent\protected\def\drawme{\thewithproperty1006 }

\startluacode

local interfaces = interfaces local implement = interfaces.implement local context = context

local d = { chickcolor = "red", beakcolor = "green", }

local drawing = utilities.templates.replacer [==[ draw fullcircle scaled 10mm withcolor %chickcolor%; draw fullcircle shifted up scaled 5mm; draw fulltriangle shifted (up+1/2right) scaled 5mm withcolor %beakcolor%; ]==]

local function chicken(value) if value == 1006 then local t = tokens.scanners.hash() or { } table.setmetatableindex(t,d) context.metafun.start() context.metafun(drawing(t,v)) context.metafun.stop() 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 \chicken\ and \drawme\chicken[chickcolor=blue,beakcolor=cyan] \stoptext

(just to remind readers of the real old and probably seldom used template mechanism)

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 -----------------------------------------------------------------

On 5/23/2021 3:45 PM, Jairo A. del Rio wrote:

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

As you're in protection ... \immutable\integerdef\MyChickenDraw 1006 \permanent\protected\def\drawme{\thewithproperty\MyChickenDraw} and yes, \integerdef is also a primitive (doesn't waste a register) 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 -----------------------------------------------------------------