Initial push

lib/collect.luau

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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