# Re: [NTG-context] t-vim module: math in "normal" code and background color

Am Mittwoch, 19. Juli 2017, 21:07:09 CEST schrieb Aditya Mahajan:
> On Wed, 19 Jul 2017, Gerion Entrup wrote:
>
> > Am Dienstag, 18. Juli 2017, 04:04:51 CEST schrieb Aditya Mahajan:
> >> On Mon, 17 Jul 2017, Gerion Entrup wrote:
> >>
> >>> Hi,
> >>>
> >>> I have two questions with the vim module.
> >>>
> >>> 1. I want to use the math mode inside the code. I've seen the escape
> >>> option,
> >>> e.g. here [1], but this seems to work only with comments. Is there a
> >>> possibility to use it directly in the code, too?
> >>
> >>
> >> Long answer. t-vim relies on vim to syntax highlight the code. Since the
> >> code is not valid python, the default python syntax highlighting will not
> >> work. In principle, it is possible to write a vim syntax highlighting
> >> script for a derivative of python where math terms are allowed, but that
> >> requires a lot of work for each language. The whole point of t-vim module
> >> was that I am lazy and don't want to write the parser for each language
> >> :-)
> >
> > I've invested some time and rewrote parts of the vimscript file of t-vim.
> > Now one or more escapechars can be defined, that helps vim to not interpret
> > the text:
>
> I'll look at this later....
>
> > Another point I saw is, that highlight together with TeX-code is not really
> > usable:
> > 
> > \usemodule[vim]
> > \definevimtyping[python][syntax=python, escape=on]
> >
> > \starttext
> > \startpython[highlight=1]
> > # Returns \m{\sum_{i=1}^{n}i \in F \int_i f}
> > \stoppython
> > \stoptext
> > 
>
> By default, the highlighting is done using the bars mechanism. It works
> for simple cases but fails with math mode (the spaces are not covered).
> One option is to highlight using the textbackground mechanism:
>
> \definetextbackground[texthighlight]
>      [
>        background=color,
>        backgroundcolor=gray,
>        frame=off,
>      ]
>
> \define[1]\texthighlight{\starttexthighlight#1\stoptexthighlight}
>
> \usemodule[vim]
> \definevimtyping[python][syntax=python, escape=on,
> highlightcommand=\texthighlight]
>
> \starttext
>
> \startpython[highlight=3]
> for x in 1:n
>    print(x)
> # Returns \m{\sum_{i=1}^{n}i \in F \int_i f}
> for x in 1:n
>    print(x)
> \stoppython
> \stoptext
Thank you, this works much better (critic on high level: the sum symbol is
higher than the highlight box, relevant on fractions).


> The spacing in math mode is bad. What is happening is the following. To
> make sure that spaces are obeyed in the code listing, I set (a modified
> version of) \activatespacehandler{on}, so the output that you get is the
> following:
>
> {\obeyspaces
>   \def\obeyedspace{\hskip\interwordspace\relax}
> \m{\sum_{i=1}^{n}i \in F \int_i f}}
>
> The simplest way to fix this is to define a new command:
>
> \define[1]\MATH{\bgroup\activatespacehandler{off}\m{\rescan{#1}}\egroup}
>
> and use \MATH{....} instead of \m{....}.
>
> I'll test this is a bit, and if the solution is robust, then I will map
> \m{...} to something equivalent to the above in the t-vim environments.
I saw the strange spacing. Thank you very much to provide a solution.

Gerion

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