TMGLEL

Stands for TextMate Grammars for Labeled Embedded Languages, a hacky way to have code chunks with a different syntax highlighting than the original language, like in Markdown fenced code blocks.

Requirements:

• Cargo (Rust).
• VS Code or maybe another code editor with support for TextMate grammars.
• For VS Code, a theme that does not color string directly, but a derivative like string.quoted, or alternatively disable semantic highlighting.

Testing:

1. Clone the repository and enter its directory.

2. Create a file called TMGLEL.toml with the following structure:

   '<language_id>' = ['<labels_id>', ...]
   ...: ...

   For example, to highlight CSS and JSON in Rust, and XML in TOML, it would be:

   rust = ['css', 'json'] # Use only the labels you
   toml = ['xml']         # need for best performance

3. Execute cargo run and check file package.json and directory syntaxes/.
   Or cargo run toml to also generate corresponding TOML files.

4. For use in VS Code, see packaging extensions.

Usage

For most languages ​​a comment starting with a case-insensitive label should highlight the next string in the same scope, not in the external or internal one:

 /* SQL */  "SELECT * FROM some_table" ; // is highlighted
 /* SQL */ ["SELECT * FROM some_table"]; // is not highlighted
[/* SQL */  "SELECT * FROM some_table"]; // is highlighted

Supported languages

Name: ID	Notice
JavaScript: javascript	Any ${...} is highlighted as an interpolation (template expression) even if it is not, so that it is more likely to be highlighted in the labeled string. The comment must be just before the string. See below.
Rhai: rhai	Same as the first point of JavaScript.
Rust: rust	Interpolations in labeled strings could be highlighted as Rust-like if there is no space between the brace and the content. For example: {var} is likely to be highlighted, but { var } never is.
TOML: toml	Strings at the beginning of a line are unhighlightable. See below.
YAML: yaml	It is not possible to highlight quoted strings or comment before the field. See below.

JavaScript

// SQL (VS Code's JS grammar gets in the way)
let not_highlighted = "SELECT * FROM some_table";

let highlighted = // SQL
	"SELECT * FROM some_table";

let alternative = /* SQL */ "SELECT * FROM some_table";

TOML

# SQL
query = 'SELECT * FROM some_table'

# JavaScript
code = '''
console.log('Hello world!');
'''

# CSS (not within the scope of the array, so its string is ignored)
styles.light = ['body { background: white }']

[styles]
# the above commented label will highlight this:
dark = 'body { color: red }'

not_highlighted = [ # CSS       the string is at the
'body { background: white }'] # beginning of the line

highlighted = [ # CSS is highlighted by the indent
	'body { background: white }']

YAML

query: # SQL
  SELECT * FROM some_table

style: > # CSS (can be `|`)
  body { color: red }

script: # JavaScript
  "console.log('Hello world!');"
  # the above line is highlighted as a JS string
  # instead of highlighting what is in quotes as JS

# JavaScript (will not be highlighted even without quotes)
unsupported: "console.log('Hello world!');"

Language labels

Should be the same as markdown code blocks, among others:

ID	Labels
bibtex	bibtex
c	c, h
clojure	clj, cljs, clojure
coffee	coffee, Cakefile, coffee.erb
cpp	cpp, c++, cxx
csharp	cs, csharp, c#
css	css, css.erb
dart	dart
diff	patch, diff, rej
dockerfile	dockerfile, Dockerfile
dosbatch	bat, batch
elixir	elixir
erlang	erlang
fsharp	fs, fsharp, f#
git_commit	COMMIT_EDITMSG, MERGE_MSG
git_rebase	git-rebase-todo
go	go, golang
groovy	groovy, gvy
handlebars	handlebars, hbs
html	html, htm, shtml, xhtml, inc, tmpl, tpl
ini	ini, conf
java	java, bsh
javascript	js, jsx, javascript, es6, mjs, cjs, dataviewjs, {.js.*}
js_regexp	regexp
json	json, json5, sublime-settings, sublime-menu, sublime-keymap, sublime-mousemap, sublime-theme, sublime-build, sublime-project, sublime-completions
jsonc	jsonc
julia	julia, {.julia.*}
latex	latex, tex
less	less
log	log
lua	lua
makefile	Makefile, makefile, GNUmakefile, OCamlMakefile
markdown	markdown, md
objc	objectivec, objective-c, mm, objc, obj-c, m, h
perl	perl, pl, pm, pod, t, PL, psgi, vcl
perl6	perl6, p6, pl6, pm6, nqp
php	php, php3, php4, php5, phpt, phtml, aw, ctp
powershell	powershell, ps1, psm1, psd1, pwsh
pug	jade, pug
python	python, py, py3, rpy, pyw, cpy, SConstruct, Sconstruct, sconstruct, SConscript, gyp, gypi, {.python.*}
r	R, r, s, S, Rprofile, {.r.*}
reaper	reaper
regexp_python	re
rhai	rhai
ruby	ruby, rb, rbx, rjs, Rakefile, rake, cgi, fcgi, gemspec, irbrc, Capfile, ru, prawn, Cheffile, Gemfile, Guardfile, Hobofile, Vagrantfile, Appraisals, Rantfile, Berksfile, Berksfile.lock, Thorfile, Puppetfile
rust	rust, rs, {.rust.*}
scala	scala, sbt
scss	scss
shellscript	shell, sh, bash, zsh, bashrc, bash_profile, bash_login, profile, bash_logout, .textmate_init, {.bash.*}
sql	sql, ddl, dml
swift	swift
toml	toml
twig	twig
typescript	typescript, ts
typescriptreact	tsx
vs_net	vb
xml	xml, xsd, tld, jsp, pt, cpt, dtml, rss, opml
xsl	xsl, xslt
yaml	yaml, yml