From cb0ebfb9a292587f761d97c7f08d646e6936c80e Mon Sep 17 00:00:00 2001
From: Georg Wiese <georgwiese@gmail.com>
Date: Mon, 3 Feb 2025 11:41:39 +0100
Subject: [PATCH] Add comment

---
 ast/src/analyzed/mod.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ast/src/analyzed/mod.rs b/ast/src/analyzed/mod.rs
index 1131aa3296..6358084c37 100644
--- a/ast/src/analyzed/mod.rs
+++ b/ast/src/analyzed/mod.rs
@@ -1008,6 +1008,7 @@ impl<T> Children<AlgebraicExpression<T>> for ExpressionList<T> {
 #[derive(
     Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Serialize, Deserialize, JsonSchema, Hash,
 )]
+/// For documentation, see the equivalent `Constr` variant in std/prelude.asm.
 pub struct PhantomBusInteractionIdentity<T> {
     // The ID is globally unique among identities.
     pub id: u64,
@@ -1017,6 +1018,9 @@ pub struct PhantomBusInteractionIdentity<T> {
     pub payload: ExpressionList<T>,
     pub latch: AlgebraicExpression<T>,
     pub folded_expressions: ExpressionList<T>,
+    // Note that in PIL, this is a list of expressions, but we'd
+    // always expect direct column references, so this is unpacked
+    // when converting from PIL to this struct.
     pub accumulator_columns: Vec<AlgebraicReference>,
 }