Add text object for paragraphs neighbouring environments

ftplugin/tex/textobj-latex.vim

@@ -7,13 +7,35 @@ if exists('g:loaded_textobj_latex')
   finish
 endif
 
+let s:re_begin = '\\begin{[^}]\+}'
+let s:re_end = '\\end{[^}]\+}'
+
+
+"
+" Join alternatives for a regular expression
+function! s:ReJoin(...)
+  return join(a:000, '\|')
+endfunction
+
+"
+" Make sure RE matches whole line
+function! s:ReWholeLine(re)
+  return '^\('.a:re.'\)\n'
+endfunction
+
+
 call textobj#user#plugin('latex', {
 \   'environment': {
 \     '*pattern*': ['\\begin{[^}]\+}.*\n\s*', '\n^\s*\\end{[^}]\+}.*$'],
 \     'select-a': 'ae',
 \     'select-i': 'ie',
 \   },
-\  'bracket-math': {
+\   'outside-environ': {
+\     '*sfile*': expand('<sfile>:p'),
+\     'select-a': 'ar',  '*select-a-function*': 's:select_a',
+\     'select-i': 'ir',  '*select-i-function*': 's:select_i'
+\   },
+\   'bracket-math': {
 \     '*pattern*': ['\\\[', '\\\]'],
 \     'select-a': 'ab',
 \     'select-i': 'ib',
@@ -43,5 +65,30 @@ call textobj#user#plugin('latex', {
 \   },
 \ })
 
-let g:loaded_textobj_latex = 1
 
+function! s:select_a()
+  " echom s:ReWholeLine(s:ReJoin(s:re_end, ''))
+  let start_pos = search(s:ReWholeLine(s:ReJoin(s:re_end, '')), 'bnW')
+  if 0 == start_pos
+    return 0  " We did not find the start of the text object
+  endif
+  let end_pos = search(s:ReWholeLine(s:ReJoin(s:re_begin, '')), 'nW')
+  if 0 == end_pos
+    return 0  " We did not find the end of the text object
+  endif
+  return ['V', [0, start_pos, 0, 0], [0, end_pos, 0, 0]]
+endfunction
+
+function! s:select_i()
+  let start_pos = search(s:ReWholeLine(s:ReJoin(s:re_end, '')), 'bnW')
+  if 0 == start_pos
+    return 0  " We did not find the start of the text object
+  endif
+  let end_pos = search(s:ReWholeLine(s:ReJoin(s:re_begin, '')), 'nW')
+  if 0 == end_pos
+    return 0  " We did not find the end of the text object
+  endif
+  return ['V', [0, start_pos + 1, 0, 0], [0, end_pos - 1, 0, 0]]
+endfunction
+
+let g:loaded_textobj_latex = 1