From f0c1243511fee046b94117c2912e2d23d08ac100 Mon Sep 17 00:00:00 2001
From: Apfelkuchen6 <apfelkuchen6@localhost>
Date: Fri, 22 Jan 2021 19:55:55 +0100
Subject: [PATCH] VimtexDocPackage: add support for environments

Previously calling VimtexDocPackage with the cursor over `\begin{foo}`
showed documentation related to \begin. Showing documentation
related to foo is probably always more useful.

As the environments are stored in the same completion file as the
commands (in the format ^\begin{foo}$), we can mostly wrap the code for
commands to get nice documentation for environments.
---
 autoload/vimtex/doc.vim | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/autoload/vimtex/doc.vim b/autoload/vimtex/doc.vim
index 1bf4870a5a..e41359a9da 100644
--- a/autoload/vimtex/doc.vim
+++ b/autoload/vimtex/doc.vim
@@ -62,11 +62,26 @@ function! s:packages_get_from_cursor() abort " {{{1
     return s:packages_from_usepackage(l:cmd)
   elseif l:cmd.name ==# '\documentclass'
     return s:packages_from_documentclass(l:cmd)
+  elseif l:cmd.name ==# '\begin'
+    return s:packages_from_environment(l:cmd)
+  elseif l:cmd.name ==# '\end'
+    return s:packages_from_environment(l:cmd)
   else
     return s:packages_from_command(strpart(l:cmd.name, 1))
   endif
 endfunction
 
+" }}}1
+function! s:packages_from_environment(env) abort " {{{1
+  try
+    let l:env = a:env.args[0].text
+  catch
+    call vimtex#log#warning('Could not parse the environment name!')
+    return {}
+  endtry
+  return s:packages_from_command('\begin{' . l:env . '}')
+endfunction
+
 " }}}1
 function! s:packages_from_usepackage(cmd) abort " {{{1
   try
@@ -129,7 +144,7 @@ function! s:packages_from_command(cmd) abort " {{{1
   endwhile
 
   let l:candidates = []
-  let l:filter = 'v:val =~# ''^' . a:cmd . '\>'''
+  let l:filter = 'v:val =~# ''^' . escape(a:cmd, '\') . '\(\W\|$\)'''
   for l:package in l:packages
     let l:cmds = filter(readfile(s:complete_dir . l:package), l:filter)
     if empty(l:cmds) | continue | endif