Move towards a new reconciler model, undo a lot of the weird stretch integrations I had done, separate out Layout and Appearance concepts, introduce ComponentKey and constructor lifecycle for components

lifecycle/src/reconciler/key.rs

@@ -0,0 +1,51 @@
+//! Implements an auto-incrementing ID for Component instances.
+
+use std::sync::Mutex;
+
+use alchemy_styles::lazy_static;
+
+lazy_static! {
+    /// Global stretch instance id allocator.
+    pub(crate) static ref INSTANCE_ALLOCATOR: Mutex<Allocator> = Mutex::new(Allocator::new());
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub(crate) struct Id {
+    id: u32
+}
+
+pub(crate) struct Allocator {
+    new_id: u32
+}
+
+impl Allocator {
+    pub fn new() -> Self {
+        Allocator { new_id: 1 }
+    }
+
+    pub fn allocate(&mut self) -> Id {
+        let id = self.new_id;
+        self.new_id += 1;
+        Id { id: id }
+    }
+}
+
+/// Used as a key for Component storage. Component instances receive these
+/// in their constructor methods, and should retain them as a tool to update their 
+/// state.
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub struct ComponentKey {
+    pub(crate) instance: Id,
+    pub(crate) local: Id,
+}
+
+impl ComponentKey {
+    /// A placeholder value, used purely for ensuring the diffing algorithm remains 
+    /// readable by reducing some unwrapping hell.
+    pub fn placeholder() -> ComponentKey {
+        ComponentKey {
+            instance: Id { id: 0 },
+            local: Id { id: 0 }
+        }
+    }
+}