Add the node intent IR types

node-graph/node-macro/src/codegen.rs

@@ -12,6 +12,7 @@ use crate::shader_nodes::{ShaderCodegen, ShaderTokens};
 
 mod classify;
 mod entries;
+mod ir;
 mod metadata;
 pub(crate) use classify::*;
 use entries::entries_tokens;

node-graph/node-macro/src/codegen/ir.rs

@@ -0,0 +1,79 @@
+//! The intent IR: a node built from its signature, from which lowering derives.
+#![allow(dead_code)]
+
+use syn::{Ident, Type, TypeParamBound};
+
+pub(crate) struct Node {
+	pub(crate) kernel: Kernel,
+	pub(crate) generics: Vec<Generic>,
+	/// Correlated rows (zipped `#[implementations]`, not crossed); empty = erased.
+	pub(crate) monomorphizations: Vec<ImplRow>,
+	pub(crate) inputs: Vec<Input>,
+	pub(crate) output: Output,
+	pub(crate) effect: Effect,
+}
+
+/// The kernel fn the node wraps.
+pub(crate) struct Kernel {
+	pub(crate) fn_name: Ident,
+}
+
+pub(crate) struct Generic {
+	pub(crate) ident: Ident,
+	pub(crate) bounds: Vec<TypeParamBound>,
+}
+
+/// One monomorphization: a concrete type per monomorphized generic.
+pub(crate) struct ImplRow {
+	pub(crate) assignments: Vec<(Ident, Type)>,
+}
+
+pub(crate) struct Input {
+	pub(crate) ident: Ident,
+	pub(crate) evaluation: Evaluation,
+	pub(crate) content: Content,
+}
+
+/// `Lazy` = `impl Node<..>`, the kernel drives it.
+pub(crate) enum Evaluation {
+	Eager,
+	Lazy,
+}
+
+pub(crate) enum Content {
+	/// Configuration; not an item.
+	Value(Type),
+	/// `subject` = its layout (attrs + rank) flows to the output.
+	Item { subject: bool, shape: ItemShape },
+}
+
+pub(crate) struct Output {
+	pub(crate) shape: ItemShape,
+	pub(crate) removes: Vec<LevelAttr>,
+}
+
+/// An item's ranked layout; `attrs` are reads on an input, writes on the output.
+pub(crate) struct ItemShape {
+	pub(crate) element: Element,
+	pub(crate) depth: u8,
+	pub(crate) attrs: Vec<LevelAttr>,
+}
+
+pub(crate) enum Element {
+	Concrete(Type),
+	/// Indexes [`Node::generics`].
+	Generic(Ident),
+}
+
+/// An attribute at a nesting level; `0` = innermost (the element's level).
+pub(crate) struct LevelAttr {
+	pub(crate) marker: Type,
+	pub(crate) level: u8,
+}
+
+pub(crate) enum Effect {
+	Pure,
+	Fallible,
+	Progressive,
+	AsyncSource,
+}