From 8160ad061328dfd40696b1c36c8aa911062cf8a4 Mon Sep 17 00:00:00 2001
From: David Vazgenovich Shakaryan <dvshakaryan@gmail.com>
Date: Sun, 1 Feb 2026 04:04:55 -0800
Subject: move string seek/transform operations to util

---
 rt.lua   | 143 +++++++++++++--------------------------------------------------
 util.lua | 102 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 131 insertions(+), 114 deletions(-)

diff --git a/rt.lua b/rt.lua
index da6c238..6b2c09d 100644
--- a/rt.lua
+++ b/rt.lua
@@ -535,173 +535,88 @@ function rt.open_option_info(opt)
 	end
 end
 
-function rt.search_text_insert_char(ev)
-	if ev.event ~= 'down' and ev.event ~= 'repeat' then
+local function search_text_transform(f, ...)
+	local menu = state:menu()
+	local str, pos = f(menu.search_text, menu.search_cursor, ...)
+	if not str then
 		return
 	end
 
-	local menu = state:menu()
-	menu:set_search_text(
-		menu.search_text:sub(1, menu.search_cursor - 1) ..
-			ev.key_text ..
-			menu.search_text:sub(menu.search_cursor),
-		menu.search_cursor + #ev.key_text)
+	menu:set_search_text(str, pos)
 	osd:dirty()
 end
 
-function rt.search_text_del_prev_char()
-	local menu = state:menu()
-	if menu.search_cursor <= 1 then
+function rt.search_text_insert_char(ev)
+	if ev.event ~= 'down' and ev.event ~= 'repeat' then
 		return
 	end
 
-	local pos = util.utf8_seek(menu.search_text, menu.search_cursor, -1)
-	menu:set_search_text(
-		menu.search_text:sub(1, pos - 1) ..
-			menu.search_text:sub(menu.search_cursor),
-		pos)
-	osd:dirty()
+	search_text_transform(util.str_insert_char, ev.key_text)
 end
 
-function rt.search_text_del_next_char()
-	local menu = state:menu()
-	if menu.search_cursor > #menu.search_text then
-		return
-	end
+function rt.search_text_del_prev_char()
+	search_text_transform(util.str_del_prev_char)
+end
 
-	menu:set_search_text(
-		menu.search_text:sub(1, menu.search_cursor - 1) ..
-			menu.search_text:sub(util.utf8_seek(
-				menu.search_text, menu.search_cursor, 1)))
-	osd:dirty()
+function rt.search_text_del_next_char()
+	search_text_transform(util.str_del_next_char)
 end
 
 function rt.search_text_del_prev_word()
-	local menu = state:menu()
-	if menu.search_cursor <= 1 then
-		return
-	end
-
-	local pos = menu.search_text:sub(1, menu.search_cursor - 1):match(
-		'()%S*%s*$')
-	menu:set_search_text(
-		menu.search_text:sub(1, pos - 1) ..
-			menu.search_text:sub(menu.search_cursor),
-		pos)
-	osd:dirty()
+	search_text_transform(util.str_del_prev_word)
 end
 
 function rt.search_text_del_next_word()
-	local menu = state:menu()
-	if menu.search_cursor > #menu.search_text then
-		return
-	end
-
-	local pos = menu.search_text:match('%s*%S*()', menu.search_cursor)
-	menu:set_search_text(
-		menu.search_text:sub(1, menu.search_cursor - 1) ..
-			menu.search_text:sub(pos))
-	osd:dirty()
+	search_text_transform(util.str_del_next_word)
 end
 
 function rt.search_text_del_to_start()
-	local menu = state:menu()
-	if menu.search_cursor <= 1 then
-		return
-	end
-
-	menu:set_search_text(menu.search_text:sub(menu.search_cursor), 1)
-	osd:dirty()
+	search_text_transform(util.str_del_to_start)
 end
 
 function rt.search_text_del_to_end()
-	local menu = state:menu()
-	if menu.search_cursor > #menu.search_text then
-		return
-	end
-
-	menu:set_search_text(menu.search_text:sub(1, menu.search_cursor - 1))
-	osd:dirty()
+	search_text_transform(util.str_del_to_end)
 end
 
 function rt.search_text_transpose_chars()
-	local menu = state:menu()
-	if menu.search_cursor <= 1 then
-		return
-	end
-
-	local pos = util.utf8_seek(menu.search_text, menu.search_cursor, 1)
-	local cp2 = util.utf8_seek(menu.search_text, pos, -1)
-	if cp2 <= 1 then
-		return
-	end
-	local cp1 = util.utf8_seek(menu.search_text, cp2, -1)
-
-	menu:set_search_text(
-		menu.search_text:sub(1, cp1 - 1) ..
-			menu.search_text:sub(cp2, pos - 1) ..
-			menu.search_text:sub(cp1, cp2 - 1) ..
-			menu.search_text:sub(pos),
-		pos)
-	osd:dirty()
+	search_text_transform(util.str_transpose_chars)
 end
 
 function rt.search_text_transpose_words()
-	local menu = state:menu()
-	if menu.search_cursor <= 1 then
-		return
-	end
-
-	local pos = menu.search_text:match('%s*%S*()', menu.search_cursor)
-	local pre, w1, sp, w2 = menu.search_text:sub(1, pos - 1):match(
-		'^(.-)(%S+)(%s+)(%S+%s*)$')
-	if not pre then
-		return
-	end
-
-	menu:set_search_text(
-		pre .. w2 .. sp .. w1 .. menu.search_text:sub(pos),
-		pos)
-	osd:dirty()
+	search_text_transform(util.str_transpose_words)
 end
 
-local function set_search_cursor(pos)
+local function search_cursor_move(f)
+	local menu = state:menu()
+	local pos = f(menu.search_text, menu.search_cursor)
+
 	if state:menu():set_search_cursor(pos) then
 		osd:dirty()
 	end
 end
 
 function rt.search_cursor_prev_char()
-	local menu = state:menu()
-	set_search_cursor(util.utf8_seek(
-		menu.search_text, menu.search_cursor, -1))
+	search_cursor_move(util.str_seek_prev_char)
 end
 
 function rt.search_cursor_next_char()
-	local menu = state:menu()
-	set_search_cursor(util.utf8_seek(
-		menu.search_text, menu.search_cursor, 1))
+	search_cursor_move(util.str_seek_next_char)
 end
 
 function rt.search_cursor_prev_word()
-	local menu = state:menu()
-	set_search_cursor(
-		menu.search_text:sub(1, menu.search_cursor - 1):match(
-			'()%S*%s*$'))
+	search_cursor_move(util.str_seek_prev_word)
 end
 
 function rt.search_cursor_next_word()
-	local menu = state:menu()
-	set_search_cursor(
-		menu.search_text:match('%s*%S*()', menu.search_cursor))
+	search_cursor_move(util.str_seek_next_word)
 end
 
 function rt.search_cursor_start()
-	set_search_cursor(1)
+	search_cursor_move(function() return 1 end)
 end
 
 function rt.search_cursor_end()
-	set_search_cursor(#state:menu().search_text + 1)
+	search_cursor_move(function(str) return #str + 1 end)
 end
 
 function rt.start_search()
diff --git a/util.lua b/util.lua
index 04e1bf6..99bba7b 100644
--- a/util.lua
+++ b/util.lua
@@ -125,4 +125,106 @@ function util.stable_kmerge(t, u, k)
 	return res
 end
 
+function util.str_seek_prev_char(str, pos)
+	return util.utf8_seek(str, pos, -1)
+end
+
+function util.str_seek_next_char(str, pos)
+	return util.utf8_seek(str, pos, 1)
+end
+
+function util.str_seek_prev_word(str, pos)
+	return str:sub(1, pos - 1):match('()%S*%s*$')
+end
+
+function util.str_seek_next_word(str, pos)
+	return str:match('%s*%S*()', pos)
+end
+
+function util.str_insert_char(str, pos, ch)
+	return str:sub(1, pos - 1) .. ch .. str:sub(pos), pos + #ch
+end
+
+function util.str_del_prev_char(str, pos)
+	if pos <= 1 then
+		return
+	end
+
+	local npos = util.utf8_seek(str, pos, -1)
+	return str:sub(1, npos - 1) .. str:sub(pos), npos
+end
+
+function util.str_del_next_char(str, pos)
+	if pos > #str then
+		return
+	end
+
+	return str:sub(1, pos - 1) .. str:sub(util.utf8_seek(str, pos, 1)), pos
+end
+
+function util.str_del_prev_word(str, pos)
+	if pos <= 1 then
+		return
+	end
+
+	local npos = str:sub(1, pos - 1):match('()%S*%s*$')
+	return str:sub(1, npos - 1) .. str:sub(pos), npos
+end
+
+function util.str_del_next_word(str, pos)
+	if pos > #str then
+		return
+	end
+
+	return str:sub(1, pos - 1) .. str:sub(str:match('%s*%S*()', pos)), pos
+end
+
+function util.str_del_to_start(str, pos)
+	if pos <= 1 then
+		return
+	end
+
+	return str:sub(pos), 1
+end
+
+function util.str_del_to_end(str, pos)
+	if pos > #str then
+		return
+	end
+
+	return str:sub(1, pos - 1), pos
+end
+
+function util.str_transpose_chars(str, pos)
+	if pos <= 1 then
+		return
+	end
+
+	local npos = util.utf8_seek(str, pos, 1)
+	local cp2 = util.utf8_seek(str, npos, -1)
+	if cp2 <= 1 then
+		return
+	end
+	local cp1 = util.utf8_seek(str, cp2, -1)
+
+	return str:sub(1, cp1 - 1) .. str:sub(cp2, npos - 1) ..
+			str:sub(cp1, cp2 - 1) .. str:sub(npos),
+		npos
+end
+
+function util.str_transpose_words(str, pos)
+	if pos <= 1 then
+		return
+	end
+
+	local npos = str:match('%s*%S*()', pos)
+	local pre, w1, sp, w2 = str:sub(1, npos - 1):match(
+		'^(.-)(%S+)(%s+)(%S+%s*)$')
+	if not pre then
+		return
+	end
+
+	return pre .. w2 .. sp .. w1 .. str:sub(npos), npos
+end
+
 return util
-- 
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