runtime/syntax/eruby.vim

" Vim syntax file
" Language:		eRuby
" Maintainer:		Tim Pope <vimNOSPAM@tpope.org>
" URL:			https://github.com/vim-ruby/vim-ruby
" Release Coordinator:	Doug Kearns <dougkearns@gmail.com>
" Last Change:		2022 Mar 18

if exists("b:current_syntax")
  finish
endif

if !exists("main_syntax")
  let main_syntax = 'eruby'
endif

if !exists("g:eruby_default_subtype")
  let g:eruby_default_subtype = "html"
endif

if &filetype =~ '^eruby\.'
  let b:eruby_subtype = matchstr(&filetype,'^eruby\.\zs\w\+')
elseif !exists("b:eruby_subtype") && main_syntax == 'eruby'
  let s:lines = getline(1)."\n".getline(2)."\n".getline(3)."\n".getline(4)."\n".getline(5)."\n".getline("$")
  let b:eruby_subtype = matchstr(s:lines,'eruby_subtype=\zs\w\+')
  if b:eruby_subtype == ''
    let b:eruby_subtype = matchstr(substitute(expand("%:t"),'\c\%(\.erb\|\.eruby\|\.erubis\|\.example\)\+$','',''),'\.\zs\w\+\%(\ze+\w\+\)\=$')
  endif
  if b:eruby_subtype == 'rhtml'
    let b:eruby_subtype = 'html'
  elseif b:eruby_subtype == 'rb'
    let b:eruby_subtype = 'ruby'
  elseif b:eruby_subtype == 'yml'
    let b:eruby_subtype = 'yaml'
  elseif b:eruby_subtype == 'js'
    let b:eruby_subtype = 'javascript'
  elseif b:eruby_subtype == 'txt'
    " Conventional; not a real file type
    let b:eruby_subtype = 'text'
  elseif b:eruby_subtype == ''
    let b:eruby_subtype = g:eruby_default_subtype
  endif
endif

if !exists("b:eruby_nest_level")
  if &syntax =~# '\<eruby\.eruby\>'
    let b:eruby_nest_level = strlen(substitute(substitute(&filetype,'\C\<eruby\>','@','g'),'[^@]','','g'))
  else
    let b:eruby_nest_level = strlen(substitute(substitute(substitute(expand("%:t"),'@','','g'),'\c\.\%(erb\|rhtml\)\>','@','g'),'[^@]','','g'))
  endif
endif
if !b:eruby_nest_level
  let b:eruby_nest_level = 1
endif

if exists("b:eruby_subtype") && b:eruby_subtype != '' && b:eruby_subtype !=? 'eruby'
  exe "runtime! syntax/".b:eruby_subtype.".vim"
  unlet! b:current_syntax
endif
syn include @rubyTop syntax/ruby.vim

syn cluster erubyRegions contains=erubyOneLiner,erubyBlock,erubyExpression,erubyComment

exe 'syn region  erubyOneLiner   matchgroup=erubyDelimiter start="^%\{1,'.b:eruby_nest_level.'\}%\@!"    end="$"     contains=@rubyTop	     containedin=ALLBUT,@erubyRegions keepend oneline'
exe 'syn region  erubyBlock      matchgroup=erubyDelimiter start="<%\{1,'.b:eruby_nest_level.'\}%\@!-\=" end="[=-]\=%\@<!%\{1,'.b:eruby_nest_level.'\}>" contains=@rubyTop  containedin=ALLBUT,@erubyRegions keepend'
exe 'syn region  erubyExpression matchgroup=erubyDelimiter start="<%\{1,'.b:eruby_nest_level.'\}=\{1,4}" end="[=-]\=%\@<!%\{1,'.b:eruby_nest_level.'\}>" contains=@rubyTop  containedin=ALLBUT,@erubyRegions keepend'
exe 'syn region  erubyComment    matchgroup=erubyDelimiter start="<%\{1,'.b:eruby_nest_level.'\}-\=#"    end="[=-]\=%\@<!%\{1,'.b:eruby_nest_level.'\}>" contains=rubyTodo,@Spell containedin=ALLBUT,@erubyRegions keepend'

" Define the default highlighting.

hi def link erubyDelimiter		PreProc
hi def link erubyComment		Comment

let b:current_syntax = 'eruby'

if main_syntax == 'eruby'
  unlet main_syntax
endif

" vim: nowrap sw=2 sts=2 ts=8: