Initial commit

src/source.luau

@@ -0,0 +1,25 @@
+if not game then script = require "test/wrap-require" end
+
+local graph = require(script.Parent.graph)
+type Node<T> = graph.Node<T>
+local create = graph.create
+local set = graph.set
+
+
+type Source<T> = (() -> T) & ((T) -> T)
+
+local function source<T>(value: T): Source<T>
+    local node, get_value = create(value :: T)
+
+    return function(...): T
+        if select("#", ...) == 0 then return get_value() end
+
+        local v = ... :: T
+        if node.cache == v and type(v) ~= "table" then return v end
+
+        set(node, v)
+        return v
+    end
+end
+
+return source :: (<T>(value: T) -> Source<T>) & (<T>() -> Source<T>)