Re: [NTG-context] Custom color schemes in t-vim

16 May 2020

      On Sat, 16 May 2020, Aditya Mahajan wrote:
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On Sat, 16 May 2020, Nicola wrote:
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On 2020-05-14, Aditya Mahajan  wrote:
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On Thu, 14 May 2020, Nicola wrote:
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Quick question: Is \startcolorscheme... \stopcolorscheme (still)
supported by t-vim?
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It is supposed to work. If it doesn't, then it is a bug. Could you
provide a complete MWE.
Please find a MWE at the bottom of this post.
The expected behaviour is that the keyword `function` in the JavaScript
snippet and `foobar` in the Ruby snippet should be colored and in
italics, as comments are. The respective Vim highlight groups are
`javaScriptFunction` and `rubyMethodName`, which both resolve to
`Function`.
The reason that there is no highlighting is because the generated `.vimout` 
does not contain any `\SYN[rubyMethodName]` or `\SYN[javaScriptFunction]` for 
the following reason:
Vim has the concept of a hierarchy of names for the syntax highlighting 
regions. For example, $VIMRUNTIME/syntax/ruby.rb contains the following 
lines:
hi def link rubyMethodName  rubyFunction
    hi def link rubyFunction  Function
So, `rubyMethodName` maps to `rubyFunction`, which in turn maps to 
`Function`. Now, a vim colorscheme first checks if a highlighting style is 
available for `rubyMethodName`; if not it tries `rubyFunction`; and if not it 
tries `Function`.
Although something similar might have been possible in 2context.vim, I follow 
the `TOHtml` function of vim, and simply created a single tag for each syntax 
highlighting element, which in this case is `Function`. So, there is no tag 
generated for `rubyMethodName` and that is why changing the syntaxhighlight 
for that doesn't change anything.
Moreover, if you comment line line 126 of `2context.vim`

     "let s:id      = synIDtrans (s:id)

[If you make a local copy of 2context.vim, then you need to run the file with `--mode=dev-vim` to ensure that the local copy is used]

Then the ruby example generates the following file:

\SYNBOL{}\SYN[rubyComment]{# Ruby program listing}\SYNEOL{}
\SYNBOL{}\SYN[rubyDefine]{def}\SYN[rubyMethodBlock]{ }\SYN[rubyMethodName]{foobar}\SYNEOL{}
\SYNBOL{}\SYN[rubyMethodBlock]{  print(}\SYN[rubyStringDelimiter]{"}\SYN[rubyString]{Hello World}\SYN[rubyStringDelimiter]{"}\SYN[rubyMethodBlock]{)}\SYNEOL{}
\SYNBOL{}\SYN[rubyDefine]{end}\SYNEOL{}

So, if you are willing to define wrappers for all ruby syntax blocks, then I can provide a configuration option so that `2context` does not apply that line.

Aditya