From abd4bc89ea8a80a6c3d3216417bb8820268be35e Mon Sep 17 00:00:00 2001
From: "Daniel J. Perry" <dperry45@gatech.edu>
Date: Mon, 16 Jan 2023 15:40:50 -0500
Subject: [PATCH] Add help mode

---
 autoload/ctrlp/help.vim | 143 ++++++++++++++++++++++++++++++++++++++++
 plugin/ctrlp.vim        |   1 +
 2 files changed, 144 insertions(+)
 create mode 100644 autoload/ctrlp/help.vim

diff --git a/autoload/ctrlp/help.vim b/autoload/ctrlp/help.vim
new file mode 100644
index 00000000..aca8318e
--- /dev/null
+++ b/autoload/ctrlp/help.vim
@@ -0,0 +1,143 @@
+" =============================================================================
+" File:          autoload/ctrlp/tag.vim
+" Description:   Help tag file extension
+" Author:        Daniel James Perry <dperry45@gatech.edu>
+" =============================================================================
+
+" Init {{{1
+if exists('g:loaded_ctrlp_help') && g:loaded_ctrlp_help
+    fini
+en
+let g:loaded_ctrlp_help = 1
+
+cal add(g:ctrlp_ext_vars, {
+  \ 'init': 'ctrlp#help#init()',
+  \ 'accept': 'ctrlp#help#accept',
+  \ 'lname': 'tags',
+  \ 'sname': 'tag',
+  \ 'enter': 'ctrlp#help#enter()',
+  \ 'type': 'tabs',
+  \ })
+
+let s:id = g:ctrlp_builtins + len(g:ctrlp_ext_vars)
+" Utilities {{{1
+fu! s:findcount(str, tgaddr)
+	let [tg, ofname] = split(a:str, '\t\+\ze[^\t]\+$')
+	let tgs = taglist('^'.tg.'$')
+	if len(tgs) < 2
+		retu [0, 0, 0, 0]
+	en
+	let bname = fnamemodify(bufname('%'), ':p')
+	let fname = expand(fnamemodify(simplify(ofname), ':s?^[.\/]\+??:p:.'), 1)
+	let [fnd, cnt, pos, ctgs, otgs] = [0, 0, 0, [], []]
+	for tgi in tgs
+		let lst = bname == fnamemodify(tgi["filename"], ':p') ? 'ctgs' : 'otgs'
+		cal call('add', [{lst}, tgi])
+	endfo
+	let ntgs = ctgs + otgs
+	for tgi in ntgs
+		let cnt += 1
+		let fulname = fnamemodify(tgi["filename"], ':p')
+		if stridx(fulname, fname) >= 0
+			\ && strlen(fname) + stridx(fulname, fname) == strlen(fulname)
+			let fnd += 1
+			let pos = cnt
+		en
+	endfo
+	let cnt = 0
+	for tgi in ntgs
+		let cnt += 1
+		if tgi["filename"] == ofname
+			if a:tgaddr != ""
+				if a:tgaddr == tgi["cmd"]
+					let [fnd, pos] = [0, cnt]
+				en
+			else
+				let [fnd, pos] = [0, cnt]
+			en
+		en
+	endfo
+	retu [1, fnd, pos, len(ctgs)]
+endf
+
+fu! s:filter(tags)
+	let nr = 0
+	wh 0 < 1
+		if a:tags == [] | brea | en
+		if a:tags[nr] =~ '^!' && a:tags[nr] !~# '^!_TAG_'
+			let nr += 1
+			con
+		en
+		if a:tags[nr] =~# '^!_TAG_' && len(a:tags) > nr
+			cal remove(a:tags, nr)
+		el
+			brea
+		en
+	endw
+	retu a:tags
+endf
+
+fu! s:syntax()
+	if !ctrlp#nosy()
+		cal ctrlp#hicheck('CtrlPTabExtra', 'Comment')
+		sy match CtrlPTabExtra '\zs\t.*\ze$'
+	en
+endf
+" Public {{{1
+fu! ctrlp#help#init()
+	if empty(s:tagfiles) | retu [] | en
+	let g:ctrlp_alltags = []
+	let tagfiles = sort(filter(s:tagfiles, 'count(s:tagfiles, v:val) == 1'))
+	for each in tagfiles
+		let alltags = s:filter(ctrlp#utils#readfile(each))
+		cal extend(g:ctrlp_alltags, alltags)
+	endfo
+	cal s:syntax()
+	retu g:ctrlp_alltags
+endf
+
+fu! ctrlp#help#accept(mode, str)
+	cal ctrlp#exit()
+	let tgaddr = matchstr(a:str, '^[^\t]\+\t\+[^\t]\+\t\zs[^\t]\{-1,}\ze\%(;"\)\?\t')
+	let str = matchstr(a:str, '^[^\t]\+\t\+[^\t]\+\ze\t')
+	let [tg, fdcnt] = [split(str, '^[^\t]\+\zs\t')[0], s:findcount(str, tgaddr)]
+	let cmds = {
+		\ 't': ['tab h'],
+		\ 'h': ['h'],
+		\ 'v': ['vert h'],
+		\ 'e': ['h'],
+		\ }
+	let utg = fdcnt[3] < 2 && fdcnt[0] == 1 && fdcnt[1] == 1
+	let cmd = cmds[a:mode][0]
+	let cmd = a:mode == 't' ? ctrlp#tabcount().cmd : cmd
+	if !fdcnt[0] || utg
+		if cmd != ''
+			exe cmd
+		en
+		let save_cst = &cst
+		set cst&
+		cal feedkeys(":".( utg ? fdcnt[2] : "" )."h ".tg."\r".(a:mode == 'e' &&
+			\ ctrlp#modfilecond(!&aw) ? " | only" : ""), 'nt')
+		let &cst = save_cst
+	el
+		let ext = ""
+		if fdcnt[1] < 2 && fdcnt[2]
+			let [sav_more, &more] = [&more, 0]
+			let ext = fdcnt[2]."\r".":let &more = ".sav_more."\r"
+		en
+		cal feedkeys(":".cmd." ".tg."\r".ext.(a:mode == 'e' &&
+			\ ctrlp#modfilecond(!&aw) ? " | only" : ""), 'nt')
+	en
+	cal ctrlp#setlcdir()
+endf
+
+fu! ctrlp#help#id()
+	retu s:id
+endf
+
+fu! ctrlp#help#enter()
+	let s:tagfiles = filter(map(split(&rtp, ','), { -> v:val . '/doc/tags' }),
+		\ 'filereadable(v:val)')
+endf
+
+" vim:fen:fdm=marker:fmr={{{,}}}:fdl=0:fdc=1:ts=2:sw=2:sts=2
diff --git a/plugin/ctrlp.vim b/plugin/ctrlp.vim
index 1e56ecaf..5d9b4fa6 100644
--- a/plugin/ctrlp.vim
+++ b/plugin/ctrlp.vim
@@ -44,6 +44,7 @@ if !exists('g:ctrlp_types') || index(g:ctrlp_types, 'mru') >= 0
 en
 
 com! -bar CtrlPTag      cal ctrlp#init(ctrlp#tag#id())
+com! -bar CtrlPHelp     cal ctrlp#init(ctrlp#help#id())
 com! -bar CtrlPQuickfix cal ctrlp#init(ctrlp#quickfix#id())
 
 com! -n=? -com=dir CtrlPDir