From 90bbe2794ff357251d8396ecc5fa0f3afdd9e6a0 Mon Sep 17 00:00:00 2001
From: sfja <sfja2004@gmail.com>
Date: Wed, 10 Jun 2026 01:26:07 +0200
Subject: [PATCH] add sim

---
 editor/src/editor/sim.ts | 55 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 editor/src/editor/sim.ts

diff --git a/editor/src/editor/sim.ts b/editor/src/editor/sim.ts
new file mode 100644
index 0000000..3601605
--- /dev/null
+++ b/editor/src/editor/sim.ts
@@ -0,0 +1,55 @@
+import * as ir from "./ir";
+
+export class Sim {
+  constructor(
+    private comp: ir.Component,
+    private inputs: boolean[],
+    private outputs: boolean[],
+  ) {}
+
+  simulate() {
+    const { comp, inputs, outputs } = this;
+
+    const stmtIdcs = new Map(comp.stmts.map((stmt, i) => [stmt, i]));
+    const state = new Map(comp.states.map((state) => [state, false]));
+
+    const regs = new Array<boolean>(comp.stmts.length).fill(false);
+
+    const operation = <Ops extends ir.Stmt[]>(
+      action: (...ops: boolean[]) => boolean,
+      ...ops: Ops
+    ) => action(...ops.map((op) => regs[stmtIdcs.get(op)!]));
+
+    for (const [i, stmt] of comp.stmts.entries()) {
+      const k = stmt.kind;
+      switch (k.tag) {
+        case "Null":
+          regs[i] = false;
+          break;
+        case "Input":
+          regs[i] = inputs[k.i];
+          break;
+        case "Output":
+          outputs[k.i] = regs[i];
+          break;
+        case "GetState":
+          regs[i] = state.get(k.state)!;
+          break;
+        case "SetState":
+          state.set(k.state, regs[i]);
+          break;
+        case "Not":
+          regs[i] = operation((v) => !v, k.op);
+          break;
+        case "And":
+          regs[i] = operation((a, b) => a && b, k.lhs, k.rhs);
+          break;
+        case "Or":
+          regs[i] = operation((a, b) => a || b, k.lhs, k.rhs);
+          break;
+        case "Component":
+          throw new Error("not implemented");
+      }
+    }
+  }
+}