mailing-list for TeXmacs Users

[Massimiliano Gubinelli <address@hidden>]

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


> 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?
>>>>>> 
>>>>>>