add CUE initial support, based on js.vim

[perelo]

Hello,

Thank you for your plugin !

Here is a first basic support for the CUE language. Basically I want to splitjoin [ 1, 2 ], f(a, b) as javascript and {x, y} as go structs, ie removing commas when splitting { ... }. So what I did is

• Copy split&join functions from autoload/js.vim for Arrays, Args and ObjectLiteral,
• :%s/#js#/#cue#/g,
• Rename Object to Struct in function names and
  1. Handle comma removal/addition
  2. Change to OneLine instead of AroundCursor (because structs are first class, but this should be configurable)
  3. Keep sj#ParseJsonObjectBody to parse structs when embedded
• Add a delimiter_padding to s:SplitList to handle both:
  1. Padding on lists, e.g. [ x, y, z ]
  2. No padding on arguments, e.g. f(1, 2)

As a quick example :

foo: { 1, x.y.z, [ x, y, z ], x: y: z: t, f(x, y, z) }.bar

splits to

foo: {
  1
  x.y.z
  [ x, y, z ]
  x: y: z: t
  f(x, y, z)
}.bar

and at the second level

foo: {
  1
  x.y.z
  [
    x,
    y,
    z
  ]
  x: y: z: t
  f(
    s,
    t,
    y
  )
}.bar

I'll leave support of if, for, let comprehensions for later but it could be nice too. CUE is very flexible on whitespace, so we could actually go far like splitjoining infix operators or whatso.

[AndrewRadev]

I seem to have added manual indenting since standard js indentation doesn't work right here. Is there existing CUE indenting in Vim or external support? It might be that removing this will still produce good results.

[perelo]

Right I missed that point. CUE have a fmt command, and there is vim-cue/indent that paraphrased JSON...

[AndrewRadev]

Instead of setting the variable, you could remove the check for it in the code. Or is that variable used in settings by one of the parsers or something?

[AndrewRadev]

Looks good, thank you for your work and for the kind words :).

I've left a few comments about code that might be unnecessary, could you check them out? Additionally, could you add a short documentation section with examples of the functionality? One line in the table of contents here, after CSS, I think:

splitjoin.vim/doc/splitjoin.txt

Lines 9 to 34 in 3e60a0b

	C......................................: |splitjoin-c|
	Clojure................................: |splitjoin-clojure|
	Coffeescript...........................: |splitjoin-coffee|
	CSS....................................: |splitjoin-css|
	Elixir.................................: |splitjoin-elixir|
	Elm....................................: |splitjoin-elm|
	Eruby..................................: |splitjoin-eruby|
	Go.....................................: |splitjoin-go|
	HAML...................................: |splitjoin-haml|
	Handlebars.............................: |splitjoin-handlebars|
	HTML...................................: |splitjoin-html|
	Java...................................: |splitjoin-java|
	Javascript.............................: |splitjoin-javascript| |splitjoin-json|
	JSX/TSX................................: |splitjoin-jsx| |splitjoin-tsx|
	Lua....................................: |splitjoin-lua|
	Perl...................................: |splitjoin-perl|
	PHP....................................: |splitjoin-php|
	Python.................................: |splitjoin-python|
	R......................................: |splitjoin-r|
	Ruby...................................: |splitjoin-ruby|
	Rust...................................: |splitjoin-rust|
	SCSS/Less..............................: |splitjoin-scss| |splitjoin-less|
	Shell..................................: |splitjoin-shell|
	TeX....................................: |splitjoin-tex|
	Vimscript..............................: |splitjoin-vimscript|
	YAML...................................: |splitjoin-yaml|

And a section that you could copy from the one above, but with three simple examples for the kinds of structures that are being handled: structs, arrays, and arguments, no need for edge cases, just a hint at what users could try:

splitjoin.vim/doc/splitjoin.txt

Lines 330 to 357 in 3e60a0b

	==============================================================================
	CSS *splitjoin-css*
	These also work for SCSS and LESS -- see |splitjoin-scss|, |splitjoin-less|.
	Style definitions ~
	>
	a { color: #0000FF; text-decoration: underline; }
	a {
	color: #0000FF;
	text-decoration: underline;
	}
	Multiline selectors ~
	>
	h1,
	h2,
	h3 {
	font-size: 18px;
	font-weight: bold;
	}
	h1, h2, h3 {
	font-size: 18px;
	font-weight: bold;
	}
	<

I'll leave support of if, for, let comprehensions for later but it could be nice too. CUE is very flexible on whitespace, so we could actually go far like splitjoining infix operators or whatso.

I'm happy to help, you could open an issue with some examples of how you'd like it to work, but I'm pretty busy with other things these days, so I can't promise when I could get around to them. If you'd be willing to try to make them work with PRs, I can give advice and try to point you in the right direction. There should be similar languages you could start from, similar to how you based this off of javascript.

[perelo]

I'm happy to help

Thank you, actually I'm also not sure I can work so much on this soon. This was more of a quick hack, but maybe the "configuration" community will come :)

If you'd be willing to try to make them work with PRs, I can give advice and try to point you in the right direction. There should be similar languages you could start from, similar to how you based this off of javascript.

Yes! CUE is heavily inspired by Go, but still have some quirks. I can try to think on some syntax for an "umbrella" issue.

[AndrewRadev]

Alright, I see that you've also started working on imports, but since you mention you might not have the time to work on it soon, I'll merge what we have so far, and you could continue in a separate PR when you have the time.