hammer/lib/collect.luau
2024-09-21 19:12:15 +02:00

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--!strict
--!optimize 2
--[[
original author by @memorycode
MIT License
Copyright (c) 2024 Michael
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
--]]
--- What signals passed to `collect()` should be able to be coerced into
export type signal_like<D, T...> = { connect: confn<D, T...>, [any]: any } | { Connect: confn<D, T...>, [any]: any }
type confn<D, T...> = (self: signal_like<D, T...>, (T...) -> ()) -> D
--- Collects all arguments fired through the given signal, and drains the collection on iteration.\
--- Expects signals to have a `Connect` ***method***.
--- ```luau
--- local sig = collect(some_signal)
---
--- -- Imagine this as an ECS scheduler loop
--- while task.wait() do
--- for index, arg1 in sig do -- arg1, arg2, etc
--- print(arg1)
--- end
--- end
--- ```
--- @param event signal<T...>
--- @return () -> (number, T...), D -- iterator and disconnector
local function collect<D, T...>(event: signal_like<D, T...>): (() -> (number, T...), D)
local storage = {}
local mt = {}
local iter = function()
local n = #storage
return function(): (number?, T...)
if n <= 0 then
mt.__iter = nil
return nil
end
n -= 1
return n + 1, unpack(table.remove(storage, 1) :: any)
end
end
local disconnect = event:Connect(function(...)
table.insert(storage, { ... })
mt.__iter = iter :: any
end)
setmetatable(storage, mt)
return storage :: any, disconnect
end
return collect