1 files changed, 75 insertions, 14 deletions

diff --git a/util/promise.lua b/util/promise.lua
index 75c8697b..c4e166ed 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") .. ")";
@@ -49,6 +50,9 @@ local function promise_settle(promise, new_state, new_next, cbs, value)
 	for _, cb in ipairs(cbs) do
 		cb(value);
 	end
+	-- No need to keep references to callbacks
+	promise._pending_on_fulfilled = nil;
+	promise._pending_on_rejected = nil;
 	return true;
 end
 
@@ -74,30 +78,84 @@ local function new_resolve_functions(p)
 	return _resolve, _reject;
 end
 
+local next_tick = function (f)
+	f();
+end
+
 local function new(f)
 	local p = setmetatable({ _state = "pending", _next = next_pending, _pending_on_fulfilled = {}, _pending_on_rejected = {} }, promise_mt);
 	if f then
-		local resolve, reject = new_resolve_functions(p);
-		local ok, ret = xpcall(f, debug.traceback, resolve, reject);
-		if not ok and p._state == "pending" then
-			reject(ret);
-		end
+		next_tick(function()
+			local resolve, reject = new_resolve_functions(p);
+			local ok, ret = xpcall(f, debug.traceback, resolve, reject);
+			if not ok and p._state == "pending" then
+				reject(ret);
+			end
+		end);
 	end
 	return p;
 end
 
 local function all(promises)
 	return new(function (resolve, reject)
-		local count, total, results = 0, #promises, {};
-		for i = 1, total do
-			promises[i]:next(function (v)
-				results[i] = v;
-				count = count + 1;
-				if count == total then
-					resolve(results);
-				end
-			end, reject);
+		local settled, results, loop_finished = 0, {}, false;
+		local total = 0;
+		for k, v in pairs(promises) do
+			if is_promise(v) then
+				total = total + 1;
+				v:next(function (value)
+					results[k] = value;
+					settled = settled + 1;
+					if settled == total and loop_finished then
+						resolve(results);
+					end
+				end, reject);
+			else
+				results[k] = v;
+			end
 		end
+		loop_finished = true;
+		if settled == total then
+			resolve(results);
+		end
+	end);
+end
+
+local function all_settled(promises)
+	return new(function (resolve)
+		local settled, results, loop_finished = 0, {}, false;
+		local total = 0;
+		for k, v in pairs(promises) do
+			if is_promise(v) then
+				total = total + 1;
+				v:next(function (value)
+					results[k] = { status = "fulfilled", value = value };
+					settled = settled + 1;
+					if settled == total and loop_finished then
+						resolve(results);
+					end
+				end, function (e)
+					results[k] = { status = "rejected", reason = e };
+					settled = settled + 1;
+					if settled == total and loop_finished then
+						resolve(results);
+					end
+				end);
+			else
+				results[k] = v;
+			end
+		end
+		loop_finished = true;
+		if settled == total then
+			resolve(results);
+		end
+	end);
+end
+
+local function join(handler, ...)
+	local promises, n = { ... }, select("#", ...);
+	return all(promises):next(function (results)
+		return handler(unpack(results, 1, n));
 	end);
 end
 
@@ -144,9 +202,12 @@ end
 return {
 	new = new;
 	resolve = resolve;
+	join = join;
 	reject = reject;
 	all = all;
+	all_settled = all_settled;
 	race = race;
 	try = try;
 	is_promise = is_promise;
+	set_nexttick = function(new_next_tick) next_tick = new_next_tick; end;
 }