From 2141d9d94a7b0c855a99e4444b093f80ee316f75 Mon Sep 17 00:00:00 2001 From: Matthew Wild Date: Thu, 25 Mar 2021 14:28:38 +0000 Subject: util.promise: Add join() convenience method Usage: promise.join(p1, p2, function (result1, result2) [...] end) --- util/promise.lua | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'util') diff --git a/util/promise.lua b/util/promise.lua index 98d313ba..5996176f 100644 --- a/util/promise.lua +++ b/util/promise.lua @@ -2,6 +2,7 @@ local promise_methods = {}; local promise_mt = { __name = "promise", __index = promise_methods }; local xpcall = require "util.xpcall".xpcall; +local unpack = table.unpack or unpack; --luacheck: ignore 113 function promise_mt:__tostring() return "promise (" .. (self._state or "invalid") .. ")"; @@ -137,6 +138,15 @@ local function all_settled(promises) end); end +local function join(...) + local promises, n = { ... }, select("#", ...); + local handler = promises[n]; + promises[n] = nil; + return all(promises):next(function (results) + return handler(unpack(results, 1, n - 1)); + end); +end + local function race(promises) return new(function (resolve, reject) for i = 1, #promises do @@ -180,6 +190,7 @@ end return { new = new; resolve = resolve; + join = join; reject = reject; all = all; all_settled = all_settled; -- cgit v1.2.3