From 06a4c3e1c870cf37ef35c4d528fd23c66d5ca260 Mon Sep 17 00:00:00 2001
From: Tom Ryder <tom@sanctum.geek.nz>
Date: Sat, 7 Jul 2018 01:18:19 +1200
Subject: Add heredoc support to Vim Perl indent plugin

This anchors lines in a Perl heredoc with no indent until it sees the
terminating word. It works really well.
---
 vim/indent/perl.vim | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 51 insertions(+), 2 deletions(-)

diff --git a/vim/indent/perl.vim b/vim/indent/perl.vim
index 51e8b26c..604b836b 100644
--- a/vim/indent/perl.vim
+++ b/vim/indent/perl.vim
@@ -10,6 +10,22 @@ let b:did_indent = 1
 setlocal indentexpr=GetPerlIndent()
 setlocal indentkeys=o,O,0},0),0]
 
+" Build patterns for heredoc indenting; note that we detect indented heredocs
+" with tildes like <<~EOF, but we don't treat them any differently; note also
+" a semicolon is required
+let s:heredoc_word = '\I\i*'
+let s:heredoc_open = '<<\~\?'
+      \ . '\('
+      \ . '\\\?' . s:heredoc_word
+      \ . '\|'
+      \ . "'" . s:heredoc_word . "'"
+      \ . '\|'
+      \ . '"' . s:heredoc_word . '"'
+      \ . '\|'
+      \ . '`' . s:heredoc_word . '`'
+      \ . '\)'
+      \ . '.*\ . ';\s*$'
+
 " Define indent function
 function! GetPerlIndent()
 
@@ -19,9 +35,42 @@ function! GetPerlIndent()
     return 0
   endif
 
-  " Get line properties
+  " Heredoc detection; start at top of buffer
+  let l:hn = 0
+  while l:hn < v:lnum
+    let l:hl = getline(l:hn)
+
+    " If we're not in a heredoc and not in a comment ...
+    if !exists('l:hw') && l:hl !~# '^\s*#'
+
+      " Line opens with a heredoc
+      let l:hm = matchstr(l:hl, s:heredoc_open)
+
+      " Store the heredoc word and make this our indent reference
+      if strlen(l:hm)
+        let l:hw = matchstr(l:hm, s:heredoc_word)
+        let l:pn = l:hn
+      endif
+
+    " If we are in a heredoc and we found the token word, finish it
+    elseif exists('l:hw') && l:hl =~# '^'.l:hw.'\>'
+      unlet l:hw
+    endif
+
+    " Bump the loop index
+    let l:hn = l:hn + 1
+
+  endwhile
+
+  " If we ended up in a heredoc, return 0 for the indent.
+  if exists('l:hw')
+    return 0
+  endif
+
+  " Get current line properties
   let l:cl = getline(v:lnum)
-  let l:ci = indent(l:cn)
+
+  " Get data of previous non-blank and non-heredoc line
   let l:pl = getline(l:pn)
   let l:pi = indent(l:pn)
 
-- 
cgit v1.2.3