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[Giovanni Piredda <address@hidden>]

Hi Joris,

thanks for the answer, will follow up on texmacs-dev (possibly in a few 
days).

Giovanni

On 18.11.20 21:31, TeXmacs wrote:
> Hi Giovanni,
>
> The explanations of Max are essentially correct.
> You need to distinguish between scheme routines that
> are useful for editing a document (like in-math?) and
> TeXmacs macros and external scheme routines that are
> useful for typesetting a document.
>
> You typically don't want to make external typesetting macros
> conditional on information that is not already in the macro
> arguments (although there can be exceptions to this rule,
> which we can discuss on texmacs-dev).
>
> If you want an external macro to do something that depends on
> the current mode (text/math/...), then you should simply pass
> the current mode (<value|mode>) as an additional argument to
> your external macro.
>
> Examples for the use of Scheme from within TeXmacs can
> be found in "The Jolly Writer", Chapter 14.
>
> Best wishes, --Joris
>
>
>
> On Wed, Nov 18, 2020 at 12:45:33PM +0100, Giovanni Piredda wrote:
> > Am 18.11.2020 um 00:57 schrieb Massimiliano Gubinelli:
> > > Dear Giovanni,
> > >
> > >   independently of the way you achieve this, I do not understand what it is 
> > > useful for in your application. Why you want to change the appearence of the 
> > > * according to whether you are in an equation or not? Cannot you simply say 
> > > that all the unit of measure are in math mode? For example, usually when I 
> > > type numbers which have a matematical meaning I always initiate an equation.
> > >
> > > Max
> >
> > Hi Max,
> >
> > you are right on this, I did not think it through but followed the
> > idea which was already in my mind, that is separate units in a
> > compound units expression with "asterisk" if in math and stretchable
> > space (0.5spc) if in text. I can first enter math, then enter the
> > macro.
> >
> > Said this, maybe it still helps to learn how to do conditional
> > typesetting. In this case it could help improve the macro, in the
> > following way: you type always the same thing, whether in text or in
> > math, and the macro itself will switch to math if it is itself
> > placed in text ("itself", not the cursor).
> >
> > I have found the file where I had tested the Scheme commands to
> > retrieve the position of the tree (it is in a directory "test trees"
> > which is inside the directory where I keep all TeXmacs tests, which
> > also has "test" in its name ;-) ), they are adapted from an example
> > in the Scheme developers' manual, and it looks like it does what I
> > want. Will probably ask for more help on the topic.
> >
> > I have in mind as a model LaTeX's siunitx, and I am going to try and
> > look for how the parts of a physical quantity are spaced there
> > (can't figure it out from LaTeX's code, am not proficient enough,
> > and did not yet find an explanation on the Internet). My idea right
> > now is that the spacing between number and unit should be larger
> > than between the unit symbols; for example (if we were typesetting
> > in text!) 1spc between number and units and 0.5spc between units.
> > Any ideas?
> >
> > G.
> >
> >
> >
> >
> > > > On 18. Nov 2020, at 00:37, Giovanni Piredda <address@hidden> wrote:
> > > >
> > > > Hi Max,
> > > >
> > > > I think I understand it now (I will try it tomorrow). Thanks for the 
> > > > explanation.
> > > >
> > > > I have a memory of seeing a procedure that finds out if a tree is inside a 
> > > > math environment, and that I have even tested it, but I need to find it again.
> > > >
> > > > Perhaps that is the way to achieve what I would like to achieve (typesetting 
> > > > something in a way that depends on where it is, and not in a way that depends 
> > > > on where *the cursor* is), but I first need to find it again in the 
> > > > documentation).
> > > >
> > > > G.
> > > >
> > > >
> > > > On 18.11.20 00:32, Massimiliano Gubinelli wrote:
> > > > > As an example, try to use my macro and then create an equation and enter it with the cursor, then make "Update all" 
> > > > > (Shift+Cmr+R) and you will see that the value of all the instances of the macro will change to "+++". If now you go 
> > > > > with the cursor on the text and then you do again "Update all", then all the instances change to "xxxx". 
> > > > > This depends where the cursor is, not where the macro are called. And "Update all" just force TeXmacs to rexpand all 
> > > > > the document from the start.
> > > > >
> > > > > Best
> > > > > Max
> > > > >
> > > > >
> > > > > > On 18. Nov 2020, at 00:29, Massimiliano Gubinelli <address@hidden> wrote:
> > > > > >
> > > > > > Dear Giovanni,
> > > > > > my understanding of the matter can be wrong (or not totally correct) however 
> > > > > > is as follows:
> > > > > >
> > > > > > 1) In order to display your document, TeXmacs need to transform the document 
> > > > > > tree into a series of boxes which indicate where and what put on the screen 
> > > > > > or on the paper. This transformation go thru several phases, one of which is 
> > > > > > the macro expansion phase, i.e. markup in the document is evaluated until 
> > > > > > primitive markup is reached, which then allows to compute boxes and the 
> > > > > > material which will eventually end up on your screen.
> > > > > >
> > > > > > 2) Every time the document is modified, for example by the user editing it 
> > > > > > inserting some text in some position of the document tree, TeXmacs perform 
> > > > > > the computations in 1) to transform the modified document tree into a new 
> > > > > > sequence of rendering instructions.
> > > > > >
> > > > > > 3) If you put some \extern markup in the document, then when TeXmacs tries to 
> > > > > > expand that markup it (by definition) goes on by calling the scheme procedure 
> > > > > > and replacing the \extern markup with the result of the scheme procedure. 
> > > > > > Now, the scheme procedure does not have *any* informations on where the 
> > > > > > \extern markup was in the document tree. So scheme cannot know if we were in 
> > > > > > an equation or in a piece of text.
> > > > > >
> > > > > > Your confusion is to believe that in-math? returns true in a situation where 
> > > > > > you use \extern inside an equation. This is not true, in my understanding.
> > > > > >
> > > > > > in-math? is true only if the *editor* is in math mode, that is your cursor is 
> > > > > > inside an equation. This is a global mode of the editor and if it happens 
> > > > > > that your macro is evaluated again at that moment, then the predicate returns 
> > > > > > true, but this does not depend on the position of your \extern in the 
> > > > > > document tree, but on the current position of the cursor at the moment 
> > > > > > TeXmacs tries to recompute that part of the tree.
> > > > > >
> > > > > > Maybe this description is not totally correct (I'm not sure how and when 
> > > > > > exaclty TeXmacs goes to a reexpansion of the macros) but seems coherent with 
> > > > > > the bizzare behaviour of your macros.
> > > > > >
> > > > > > Also try \extern with a procedure of the form
> > > > > >
> > > > > > (define (myfunc) (if (in-math?) "+++" "xxxx")))
> > > > > > to see how, even when you put it in regular text, you can have "+++" if, 
> > > > > > right away you then enter into math mode.
> > > > > >
> > > > > > HTH,
> > > > > > Max
> > > > > >
> > > > > >
> > > > > >
> > > > > > > On 17. Nov 2020, at 23:29, Giovanni Piredda <address@hidden> wrote:
> > > > > > >
> > > > > > > I am going to answer your previous message (thanks for that by the way) but 
> > > > > > > before that: I do not follow the explanation in this message on the in-math? 
> > > > > > > predicate, I have an idea of what you might mean, but maybe the idea is wrong 
> > > > > > > :-)
> > > > > > >
> > > > > > > Let me write it down here.
> > > > > > >
> > > > > > > Starting from:
> > > > > > >
> > > > > > > "As I open the file, where I have the macro (which calls Scheme code via 
> > > > > > > extern) both inside math and outside math, they are all executed as if in text 
> > > > > > > mode.
> > > > > > >
> > > > > > > If I edit one of them, now the predicate in-math? has effect."
> > > > > > >
> > > > > > > you say that when I open the file TeXmacs is only typesetting (and therefore 
> > > > > > > uses the default function, as (in math?) returns always #f), but when I am 
> > > > > > > editing TeXmacs knows what I am editing and lets Scheme know. Is it that?
> > > > > > >
> > > > > > > The follow-up question in this case is how can I obtain what I want, that is 
> > > > > > > a different function being called ever time the macro is executed, that is 
> > > > > > > also at the opening of the file. The aim seems sensible to me - typesetting 
> > > > > > > something in one way when in math and in one way when in text (as I said 
> > > > > > > above, now it is working when I write/edit, it is not working if I close and 
> > > > > > > open again a document).
> > > > > > >
> > > > > > > Besides, doing Document->Update all hangs the document for a one/two minutes 
> > > > > > > (Ubuntu 20.10, I observed it in another document too), makes the macros work 
> > > > > > > well (upright in math, no asterisks, so it is recognizing the math), which is 
> > > > > > > pretty surprising, but destroys the page setup (margins are lost).
> > > > > > >
> > > > > > > G.
> > > > > > >
> > > > > > >
> > > > > > > On 17.11.20 22:50, Massimiliano Gubinelli wrote:
> > > > > > > > Going back to your attempt: I think that the predicate in-math? cannot be 
> > > > > > > > used to check whether the typesetter is working on an equation or not. No 
> > > > > > > > information is passed to Scheme about the internal status of the typesetter 
> > > > > > > > when you call a \extern markup. You can pass informations only via 
> > > > > > > > parameters. So your unitSpacer has no way to know if the evaluation is inside 
> > > > > > > > some math markup or not.
> > > > > > > >
> > > > > > > > The predicates in-math?, etc.. are just to check if the editor is in text, 
> > > > > > > > prog, or math mode, for example. Thats is completely separate on the status 
> > > > > > > > of the typesetter.
> > > > > > > >
> > > > > > > > HTH,
> > > > > > > >
> > > > > > > > Max
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > > On 17. Nov 2020, at 19:25, Giovanni Piredda <address@hidden> wrote:
> > > > > > > > >
> > > > > > > > > I post this here because I think that while being about Scheme in TeXmacs is 
> > > > > > > > > still of general interest. I have found a way of circumventing both issues 
> > > > > > > > > (which may be ok, in case I will ask about this in another post) but I am 
> > > > > > > > > curious to know the reason of the behaviours I observe.
> > > > > > > > >
> > > > > > > > > First issue.
> > > > > > > > >
> > > > > > > > > I have defined a Scheme function with the following:
> > > > > > > > >
> > > > > > > > > (tm-define (unitSpacer) ; default, will be used in regular text
> > > > > > > > >        `(hspace "0.5spc"))
> > > > > > > > > (tm-define (unitSpacer)
> > > > > > > > >        (:require (in-math?))
> > > > > > > > >        "*")
> > > > > > > > >
> > > > > > > > > As far as I understand, the first definition is the default and it is 
> > > > > > > > > overridden by the second when I am in math.
> > > > > > > > >
> > > > > > > > > In my tests, this happens only in open documents. At the first opening of a 
> > > > > > > > > document, only the first definition is used. Does anyone have a hint on what 
> > > > > > > > > is happening? Developers ;-) ?
> > > > > > > > >
> > > > > > > > > ===
> > > > > > > > >
> > > > > > > > > Second issue.
> > > > > > > > >
> > > > > > > > > In math mode, the program I wrote outputs groups of letters, each wrapped in a 
> > > > > > > > > <with|math-font-shape|right primitive, and interleaved with the character "*".
> > > > > > > > >
> > > > > > > > > Example of output, copied from the terminal using (display ...)
> > > > > > > > >
> > > > > > > > > <tree 2 <with|math-font-shape|right|kg>*<with|math-font-shape|right|m>>
> > > > > > > > >
> > > > > > > > > I call this from a TeXmacs macro in math mode and I get a typeset output 
> > > > > > > > > where the asterisk appears as such (while I would like it to be interpreted 
> > > > > > > > > as an implicit multiplication)
> > > > > > > > >
> > > > > > > > > If I copy the output from the terminal, strip the outermost <tree primitive 
> > > > > > > > > and place it inside a math primitive (opening the .tm file with a text editor) 
> > > > > > > > > the asterisks do not appear (as I thought they shouldn't).
> > > > > > > > >
> > > > > > > > > Again, suggestions?