prosody
b1c6ede17592
util/promise.lua

Find changesets by keywords by author, files, the commit message, revision number or hash, or revset expression.

Software / code / prosody

Annotate

util/promise.lua @ 9517:b1c6ede17592

util.promise: Add promise.try()
author Matthew Wild <mwild1@gmail.com>
date Thu, 18 Oct 2018 18:03:31 +0100
parent 9515:2571c65b972f
child 9546:c93496785022
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
9456
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
1 local promise_methods = {};
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
2 local promise_mt = { __name = "promise", __index = promise_methods };
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
3
9515
2571c65b972f util.promise: Add a string representation
Kim Alvefur <zash@zash.se>
parents: 9514
diff changeset
4 function promise_mt:__tostring()
2571c65b972f util.promise: Add a string representation
Kim Alvefur <zash@zash.se>
parents: 9514
diff changeset
5 return "promise (" .. (self._state or "invalid") .. ")";
2571c65b972f util.promise: Add a string representation
Kim Alvefur <zash@zash.se>
parents: 9514
diff changeset
6 end
2571c65b972f util.promise: Add a string representation
Kim Alvefur <zash@zash.se>
parents: 9514
diff changeset
7
9456
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
8 local function is_promise(o)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
9 local mt = getmetatable(o);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
10 return mt == promise_mt;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
11 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
12
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
13 local function next_pending(self, on_fulfilled, on_rejected)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
14 table.insert(self._pending_on_fulfilled, on_fulfilled);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
15 table.insert(self._pending_on_rejected, on_rejected);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
16 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
17
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
18 local function next_fulfilled(promise, on_fulfilled, on_rejected) -- luacheck: ignore 212/on_rejected
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
19 on_fulfilled(promise.value);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
20 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
21
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
22 local function next_rejected(promise, on_fulfilled, on_rejected) -- luacheck: ignore 212/on_fulfilled
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
23 on_rejected(promise.reason);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
24 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
25
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
26 local function promise_settle(promise, new_state, new_next, cbs, value)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
27 if promise._state ~= "pending" then
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
28 return;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
29 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
30 promise._state = new_state;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
31 promise._next = new_next;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
32 for _, cb in ipairs(cbs) do
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
33 cb(value);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
34 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
35 return true;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
36 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
37
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
38 local function new_resolve_functions(p)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
39 local resolved = false;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
40 local function _resolve(v)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
41 if resolved then return; end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
42 resolved = true;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
43 if is_promise(v) then
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
44 v:next(new_resolve_functions(p));
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
45 elseif promise_settle(p, "fulfilled", next_fulfilled, p._pending_on_fulfilled, v) then
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
46 p.value = v;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
47 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
48
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
49 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
50 local function _reject(e)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
51 if resolved then return; end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
52 resolved = true;
9512
439cf3bbe5f3 util.promise: Also support automatic resolution by returning a promise from an on_reject handler
Matthew Wild <mwild1@gmail.com>
parents: 9510
diff changeset
53 if is_promise(e) then
9517
b1c6ede17592 util.promise: Add promise.try()
Matthew Wild <mwild1@gmail.com>
parents: 9515
diff changeset
54 print ("WOAH") assert(false)
9512
439cf3bbe5f3 util.promise: Also support automatic resolution by returning a promise from an on_reject handler
Matthew Wild <mwild1@gmail.com>
parents: 9510
diff changeset
55 e:next(new_resolve_functions(p));
439cf3bbe5f3 util.promise: Also support automatic resolution by returning a promise from an on_reject handler
Matthew Wild <mwild1@gmail.com>
parents: 9510
diff changeset
56 elseif promise_settle(p, "rejected", next_rejected, p._pending_on_rejected, e) then
9456
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
57 p.reason = e;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
58 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
59 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
60 return _resolve, _reject;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
61 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
62
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
63 local function wrap_handler(f, resolve, reject)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
64 return function (param)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
65 local ok, ret = pcall(f, param);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
66 if ok then
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
67 resolve(ret);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
68 else
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
69 reject(ret);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
70 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
71 end;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
72 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
73
9513
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
74 local function new(f)
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
75 local p = setmetatable({ _state = "pending", _next = next_pending, _pending_on_fulfilled = {}, _pending_on_rejected = {} }, promise_mt);
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
76 if f then
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
77 local resolve, reject = new_resolve_functions(p);
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
78 local ok, ret = pcall(f, resolve, reject);
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
79 if not ok and p._state == "pending" then
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
80 reject(ret);
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
81 end
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
82 end
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
83 return p;
9456
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
84 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
85
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
86 local function all(promises)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
87 return new(function (resolve, reject)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
88 local count, total, results = 0, #promises, {};
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
89 for i = 1, total do
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
90 promises[i]:next(function (v)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
91 results[i] = v;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
92 count = count + 1;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
93 if count == total then
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
94 resolve(results);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
95 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
96 end, reject);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
97 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
98 end);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
99 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
100
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
101 local function race(promises)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
102 return new(function (resolve, reject)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
103 for i = 1, #promises do
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
104 promises[i]:next(resolve, reject);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
105 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
106 end);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
107 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
108
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
109 local function resolve(v)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
110 return new(function (_resolve)
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
111 _resolve(v);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
112 end);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
113 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
114
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
115 local function reject(v)
9510
8ef46d09386a util.promise: Fix promise.reject() to return a rejected promise, and fix buggy test for it
Matthew Wild <mwild1@gmail.com>
parents: 9456
diff changeset
116 return new(function (_, _reject)
9456
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
117 _reject(v);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
118 end);
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
119 end
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
120
9517
b1c6ede17592 util.promise: Add promise.try()
Matthew Wild <mwild1@gmail.com>
parents: 9515
diff changeset
121 local function try(f)
b1c6ede17592 util.promise: Add promise.try()
Matthew Wild <mwild1@gmail.com>
parents: 9515
diff changeset
122 return resolve():next(function () return f(); end);
b1c6ede17592 util.promise: Add promise.try()
Matthew Wild <mwild1@gmail.com>
parents: 9515
diff changeset
123 end
b1c6ede17592 util.promise: Add promise.try()
Matthew Wild <mwild1@gmail.com>
parents: 9515
diff changeset
124
9513
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
125 function promise_methods:next(on_fulfilled, on_rejected)
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
126 return new(function (resolve, reject) --luacheck: ignore 431/resolve 431/reject
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
127 self:_next(
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
128 on_fulfilled and wrap_handler(on_fulfilled, resolve, reject) or nil,
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
129 on_rejected and wrap_handler(on_rejected, resolve, reject) or nil
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
130 );
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
131 end);
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
132 end
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
133
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
134 function promise_methods:catch(on_rejected)
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
135 return self:next(nil, on_rejected);
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
136 end
4f4f9823bd1d util.promise: Some code relocation
Matthew Wild <mwild1@gmail.com>
parents: 9512
diff changeset
137
9514
9db707a86a25 util.promise: Add promise:finally()
Matthew Wild <mwild1@gmail.com>
parents: 9513
diff changeset
138 function promise_methods:finally(on_finally)
9db707a86a25 util.promise: Add promise:finally()
Matthew Wild <mwild1@gmail.com>
parents: 9513
diff changeset
139 local function _on_finally(value) on_finally(); return value; end
9db707a86a25 util.promise: Add promise:finally()
Matthew Wild <mwild1@gmail.com>
parents: 9513
diff changeset
140 local function _on_catch_finally(err) on_finally(); return reject(err); end
9db707a86a25 util.promise: Add promise:finally()
Matthew Wild <mwild1@gmail.com>
parents: 9513
diff changeset
141 return self:next(_on_finally, _on_catch_finally);
9db707a86a25 util.promise: Add promise:finally()
Matthew Wild <mwild1@gmail.com>
parents: 9513
diff changeset
142 end
9db707a86a25 util.promise: Add promise:finally()
Matthew Wild <mwild1@gmail.com>
parents: 9513
diff changeset
143
9456
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
144 return {
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
145 new = new;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
146 resolve = resolve;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
147 reject = reject;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
148 all = all;
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
149 race = race;
9517
b1c6ede17592 util.promise: Add promise.try()
Matthew Wild <mwild1@gmail.com>
parents: 9515
diff changeset
150 try = try;
9456
d54a0e129af8 util.promise: ES6-like API for promises
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
151 }