File

util/bitcompat.lua @ 10973:39991e40d1dc

util.dbuffer: dynamic string buffer Similar to util.ringbuffer (and shares almost identical API). Differences: - size limit is optional and dynamic - does not allocate a fixed buffer of max_size bytes - focus on simply storing references to existing string objects where possible, avoiding unnecessary allocations - references are still stored in a ring buffer to enable use as a fast FIFO Optional second parameter to new() provides the number of ring buffer segments. On Lua 5.2 on my laptop, a segment is ~19 bytes. If the ring buffer fills up, the next write will compact all strings into a single item.
author Matthew Wild <mwild1@gmail.com>
date Fri, 26 Jun 2020 16:41:31 +0100
parent 10241:48f7cda4174d
child 12573:0f4feaf9ca64
line wrap: on
line source

-- Compatibility layer for bitwise operations

-- First try the bit32 lib
-- Lua 5.3 has it with compat enabled
-- Lua 5.2 has it by default
if _G.bit32 then
	return _G.bit32;
else
	-- Lua 5.1 may have it as a standalone module that can be installed
	local ok, bitop = pcall(require, "bit32")
	if ok then
		return bitop;
	end
end

do
	-- Lua 5.3 and 5.4 would be able to use native infix operators
	local ok, bitop = pcall(require, "util.bit53")
	if ok then
		return bitop;
	end
end

do
	-- Lastly, try the LuaJIT bitop library
	local ok, bitop = pcall(require, "bit")
	if ok then
		return bitop;
	end
end

error "No bit module found. See https://prosody.im/doc/depends#bitop";