parsing of emphasis versus links

parsing of emphasis versus links

[Eric S Fraga]

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Hello,

I have been playing with using embedded calc equations in org mode.  I
have tried filters and with org emphasis markers but finally have come
around to using the new org link capabilities.  Thank you John for
these!

I've defined the following:

#+begin_src emacs-lisp
  (org-link-set-parameters
   "calc"
   :export (lambda (path desc backend)
             (cond
              ((eq 'latex backend)
               (format "\\texttt{%s}" desc))))
   :face '(:foreground "chartreuse"))
#+end_src 

which I then use like this:

#+begin_src org
  [[calc:][Pv := 10^(6.886 - 1175.817 / (100 + 224.867)) => 1847.653]]
#+end_src

and with appropriate settings for calc [1], calc can manipulate and
evaluate the expressions.  So far, so good.

Two minor issues:

1. the fontification doesn't colour the links in the colour I would like
   (chartreuse, #7fff00).

2. if I have two expressions close enough, both with := and =>
   operators, org seems to get confused and interprets two of the =
   symbols, each from one expression, as emphasis markers, as in this
   example:

   #+begin_src org
     [[calc:][y := 3 x - 5 => 55]] [[calc:][z := sqrt(y) => 7.416]]
   #+end_src

Screenshot attached showing both problems: colour and second = sign
disappearing in first link and first = sign in second link.

Any suggestions on how to improve/fix these aspects?  Both are minor
presentation issues and everything else is working very well.  Calc
allows me to work with these expressions easily in org now!

Many thanks,
eric


Footnotes: 
[1]  Settings using calc: links:

     #+begin_src emacs-lisp
       (defun esf/org-mode-calc-settings ()
         (setq calc-embedded-open-formula "\\[\\[calc:]\\["
               calc-embedded-open-new-formula "[[calc:]["
               calc-embedded-close-formula "]]"
               calc-embedded-close-new-formula "]]"))
       (add-hook 'org-mode-hook #'esf/org-mode-calc-settings)
     #+end_src 

-- 
: Eric S Fraga (0xFFFCF67D), Emacs 26.0.50.1, Org release_9.0.5-370-g9f3a02.dirty

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Re: parsing of emphasis versus links

[John Kitchin]

I can not reproduce all the things you report.

I think part of the problem is [calc:]. I have to have at least two
characters of path to get a link that is colored.

Eric S Fraga writes:

> Hello,
>
> I have been playing with using embedded calc equations in org mode.  I
> have tried filters and with org emphasis markers but finally have come
> around to using the new org link capabilities.  Thank you John for
> these!
>
> I've defined the following:
>
> #+begin_src emacs-lisp
>   (org-link-set-parameters
>    "calc"
>    :export (lambda (path desc backend)
>              (cond
>               ((eq 'latex backend)
>                (format "\\texttt{%s}" desc))))
>    :face '(:foreground "chartreuse"))
> #+end_src
>
> which I then use like this:
>
> #+begin_src org
>   [[calc:][Pv := 10^(6.886 - 1175.817 / (100 + 224.867)) => 1847.653]]
> #+end_src
>
> and with appropriate settings for calc [1], calc can manipulate and
> evaluate the expressions.  So far, so good.
>
> Two minor issues:
>
> 1. the fontification doesn't colour the links in the colour I would like
>    (chartreuse, #7fff00).

I get partial chartreuse, but there are some fontlock that can go on
top, e.g. if it looks like a latex fragment.

>
> 2. if I have two expressions close enough, both with := and =>
>    operators, org seems to get confused and interprets two of the =
>    symbols, each from one expression, as emphasis markers, as in this
>    example:
>
>    #+begin_src org
>      [[calc:][y := 3 x - 5 => 55]] [[calc:][z := sqrt(y) => 7.416]]
>    #+end_src

I can reproduce the issue above, but I have no way to help improve it.
This particular case looks like emphasis from a simple regexp pov.
Fixing it might require checking that the start/end are in the
same org-element maybe.

>
> Screenshot attached showing both problems: colour and second = sign
> disappearing in first link and first = sign in second link.
>
> Any suggestions on how to improve/fix these aspects?  Both are minor
> presentation issues and everything else is working very well.  Calc
> allows me to work with these expressions easily in org now!
>
> Many thanks,
> eric
>
>
> Footnotes:
> [1]  Settings using calc: links:
>
>      #+begin_src emacs-lisp
>        (defun esf/org-mode-calc-settings ()
>          (setq calc-embedded-open-formula "\\[\\[calc:]\\["
>                calc-embedded-open-new-formula "[[calc:]["
>                calc-embedded-close-formula "]]"
>                calc-embedded-close-new-formula "]]"))
>        (add-hook 'org-mode-hook #'esf/org-mode-calc-settings)
>      #+end_src


--
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu

Re: parsing of emphasis versus links

[Eric S Fraga]

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On Friday, 17 Mar 2017 at 19:32, John Kitchin wrote:
> I can not reproduce all the things you report.

Hi John,

But you did reproduce most so it's not my imagination :-)

> I think part of the problem is [calc:]. I have to have at least two
> characters of path to get a link that is colored.

Ah, okay.  I'll think about extending the template for embedded calc
recognition.

> This particular case looks like emphasis from a simple regexp pov.

Yes, indeed.  I'm getting around it by making sure there is only one
calc: link per line but not ideal.  More thinking required!

Thanks for having a look.

-- 
: Eric S Fraga (0xFFFCF67D), Emacs 26.0.50, Org release_9.0.5-378-gf6f02e.dirty

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