1 files changed, 86 insertions, 0 deletions
diff --git a/util.lua b/util.lua
new file mode 100644
index 0000000..da9702e
--- /dev/null
+++ b/util.lua
@@ -0,0 +1,86 @@
+-- Copyright 2025 David Vazgenovich Shakaryan
+
+local mp_utils = require('mp.utils')
+
+local util = {}
+
+function util.copy_table(t)
+	local u = {}
+	for k, v in pairs(t) do
+		u[k] = v
+	end
+	return u
+end
+
+function util.reverse(t)
+	for i = 1, #t/2 do
+		t[i], t[#t-i+1] = t[#t-i+1], t[i]
+	end
+end
+
+function util.strip(str)
+	return (str:gsub('^%s*(.-)%s*$', '%1'))
+end
+
+-- skips over utf8 continuation bytes (10xxxxxx)
+-- valid positions range from 1 to #str + 1 (*after* the last byte)
+function util.utf8_seek(str, pos, n)
+	local step = n > 0 and 1 or -1
+	local test = n > 0
+		and function() return pos > #str end
+		or function() return pos <= 1 end
+
+	while n ~= 0 and not test() do
+		repeat
+			pos = pos + step
+		until test() or bit.band(str:byte(pos), 0xc0) ~= 0x80
+
+		n = n - step
+	end
+	return pos
+end
+
+-- wraps string into a table of strings. spaces are not removed, resulting in
+-- width-1 visible chars; newlines and end of string are handled similarly for
+-- consistency. words longer than width are not broken. optional cont_width can
+-- be specified to use a different width for continuation lines.
+function util.wrap(str, width, cont_width)
+	local t = {}
+	local start, stop = 0, 0
+	while stop < #str do
+		local i = str:find('[ \n]', stop + 1) or #str + 1
+		if i - start >= width then
+			t[#t+1] = str:sub(start, stop)
+			start = stop + 1
+
+			if cont_width then
+				width = cont_width
+			end
+		end
+		stop = i
+
+		if str:byte(stop) == 10 or stop >= #str then
+			t[#t+1] = str:sub(start, stop - 1) .. ' '
+			start = stop + 1
+		end
+	end
+	return t
+end
+
+function util.read_json_file(path)
+	local f = io.open(path, 'r')
+	if not f then
+		return {}
+	end
+	local json = f:read('*all')
+	f:close()
+	return mp_utils.parse_json(json)
+end
+
+function util.write_json_file(path, data)
+	local f = io.open(path, 'w')
+	f:write(mp_utils.format_json(data), '\n')
+	f:close()
+end
+
+return util