Add conceal for \lvert, \rvert...

[Freed-Wu]

Describe the solution you'd like

e.g.

syntax match texMathSymbol "\\lvert"               contained conceal cchar=|
syntax match texMathSymbol "\\lVert"               contained conceal cchar=ǁ
syntax match texMathSymbol "\\rvert"               contained conceal cchar=|
syntax match texMathSymbol "\\rVert"               contained conceal cchar=ǁ

test

$$\lVert \mathrm{w} \rVert_2^2$$

[lervag]

Done.

[Freed-Wu]

A package named physics provide the macro \abs{w} and \norm{w} to wrap \lverb w\rverb and \lVerb w\rVerb. Can them be concealed like \verb? Thanks!

[Freed-Wu]

And I think

syntax match texCmdAccent   "\\i\>"  conceal cchar=ı
syntax match texCmdAccent   "\\j\>"  conceal cchar=ȷ

is correct, just like \O and \o.

[Freed-Wu]

How about

syntax match texCmdAccent   "\\lq\>"  conceal cchar=`
syntax match texCmdAccent   "\\rq\>"  conceal cchar='

? Maybe punctuations can be concealed.

[lervag]

A package named physics provide the macro \abs{w} and \norm{w} to wrap \lverb w\rverb and \lVerb w\rVerb. Can them be concealed like \verb? Thanks!

I assume you mean \vert here? This is somewhat harder to do. I know a method, but is really quite hacky. I think it may be better to not go there...

[Freed-Wu]

Oh, I see. Vim' conceal seems to be able to support only one character. Thanks!

[lervag]

Yes, precicely. I could conceal the initial \abs{ and the suffix } individually, but the matching is then more complex and error prone. So I'm not sure if it is worth the effort.

[Freed-Wu]

I found \backslash has been concealed to \ in math mode. How about concealing \slash to /? It can work in non-math mode and math mode.

[lervag]

Yes, no problem. I've added it as a "fancy" conceal.

[Freed-Wu]

In tex,

`'

``''

!`

?`

will output

‘’

“”

¡

¿

I notice double quotes has been concealed in vimtex:

" autoload/vimtex/syntax/core.vim:1832-1833
syntax match texLigature    "``"     conceal cchar=“
syntax match texLigature    "''"     conceal cchar=”

How about others?

[Freed-Wu]

And in tex, \sb, \sp have same function as _ and ^, 1\over2 have same function as \frac12. Should them be concealed, too?

[lervag]

I'm not sure. I don't think we should aim for "full rendering". I might agree that 1 \over 2 is ok as an alternative to \frac 1 2, although all of this do feel a little bit like adding bloat. Do you find that you truly miss these conceals?

[Freed-Wu]

I agree with you. If some of them are not easy to be realized and no one like these macros, support them are not valuable. However, if something don't be supported, the document should explain which macros aren't supported and why them are not supported to avoid some one has any confusion about them. Thanks!

[lervag]

However, if something don't be supported, the document should explain which macros aren't supported and why them are not supported to avoid some one has any confusion about them. Thanks!

Sorry, but I don't agree. There are way too many elements that could be concealed to document every element that we don't conceal. My approach so far has been to be pragmatic - if someone suggests something that should be concealed and where I agree it has value, I try to add it. In some cases I say no, either because of complexity or because I don't see the value. If I were to document every decision it would i) make the documentation more bloated, and ii) add to the already high workload of maintaining VimTeX.

I would not mind considering PR's, though. Perhaps I'm wrong about i) and it could be possible to add these things to the docs in a good way. But I will personally prioritize other activities that I believe brings more value to the community.

[Freed-Wu]

There are way too many elements that could be concealed to document every element that we don't conceal. My approach so far has been to be pragmatic - if someone suggests something that should be concealed and where I agree it has value, I try to add it. In some cases I say no, either because of complexity or because I don't see the value.

Thanks for your explanation. Add some not complex and valuable function is the true duty. So just add some necessary conceal is enough.

So, can it be supported? Thanks!

diff --git a/autoload/vimtex/syntax/core.vim b/autoload/vimtex/syntax/core.vim
index 333e140a..22801934 100644
--- a/autoload/vimtex/syntax/core.vim
+++ b/autoload/vimtex/syntax/core.vim
@@ -1828,9 +1828,13 @@ function! s:match_conceal_accents() abort " {{{1
   syntax match texCmdLigature "\\ss\>" conceal cchar=ß
   syntax match texLigature    "--"     conceal cchar=–
   syntax match texLigature    "---"    conceal cchar=—
+  syntax match texLigature    "`"     conceal cchar=‘
+  syntax match texLigature    "'"     conceal cchar=’
   syntax match texLigature    "``"     conceal cchar=“
   syntax match texLigature    "''"     conceal cchar=”
   syntax match texLigature    ",,"     conceal cchar=„
+  syntax match texLigature    "!`"     conceal cchar=¡
+  syntax match texLigature    "?`"     conceal cchar=¿
 endfunction

[lervag]

I'm not so sure about concealing the ` and ', but I'll add the other two immediately. The former: would it not be confusing?

[Freed-Wu]

Thanks.

Maybe can try ' and ```, then see if any bug will happen?

[lervag]

Maybe can try ' and ```, then see if any bug will happen?

What do you mean? Reg.

  syntax match texLigature    "`"     conceal cchar=‘
  syntax match texLigature    "'"     conceal cchar=’

my point was that I believe these conceals may be confusing to the user. Perhaps I'm wrong. If you disagree and still think these will be useful, then OK, I'll add them.

[Freed-Wu]

I'm not offensive...:(

I want to know which situation these conceals will be confusing? Did you mean any code like \catcode`\@ = \active or other situations I don't know about ```? These situations maybe happen. In my opinion, these conceals, can be provided as a key of g:vimtex_syntax_conceal, like:

let g:vimtex_syntax_conceal = {'ligature': 0}

By default, it is disabled. If anyone know what these ligature means, they can enable it by themselves. It should not effect too many people, I think.

[Freed-Wu]

I also don't think these conceal will be used by many people especially who don't use any languages containing ligatures. However, Knuth designed them in Tex, so they looks like a standard (albeit not many people know and use). If provide an option to respect standard may be better. That is my opinion. No offend.

[lervag]

I'm not offensive...:(

No offense taken, and I hope I don't come off as offensive myself - that is not my intention!

By default, it is disabled. If anyone know what these ligature means, they can enable it by themselves. It should not effect too many people, I think.

No, currently, this is enabled by default and is provided under the accents key. Perhaps we should separate and add ligatures as a new key? But it should be enabled by default, I think, else it will be a breaking change.

I also don't think these conceal will be used by many people especially who don't use any languages containing ligatures. However, Knuth designed them in Tex, so they looks like a standard (albeit not many people know and use). If provide an option to respect standard may be better. That is my opinion. No offend.

Again, no offense. I just want to think things through before I implement them. But OK, I'll add the suggested conceals as well together with the new ligatures key that allows more fine grained control if anyone should not like this. It's a good compromise, I think.

[Freed-Wu]

Thanks for your explanation. I support this change.