idea

Cargo.lock

@@ -813,6 +813,10 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f27ae1dd37df86211c42e150270f82743308803d90a6f6e6651cd730d5e1732f"
 
+[[package]]
+name = "dag"
+version = "0.1.0"
+
 [[package]]
 name = "ddsfile"
 version = "0.5.2"

Cargo.toml

@@ -7,6 +7,7 @@ members = [
 	"integration-testing",
 	"lib/bsp_loader",
 	"lib/common",
+	"lib/dag",
 	"lib/deferred_loader",
 	"lib/fixed_wide",
 	"lib/linear_ops",

lib/dag/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "dag"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+
+[lints]
+workspace = true

lib/dag/src/lib.rs

@@ -0,0 +1,16 @@
+// typestate dag with lazy just-in-time execution
+struct States<S1,S2>(S1,S2);
+
+struct Known<T>(T);
+struct NeedsRecalculate;
+
+fn a(){
+	// Construct a DAG such that S2 depends on S1
+	// let dag=Dag:new();
+	// Initial state
+	let state=States(Known(1),Known(1));
+	// set_state1 changes S2 to NeedsRecalculate
+	state.set_state1(2);
+	// get_state2 calculates S2
+	let s2=state.get_state2();
+}