From de32aa374ef111e69a7b9a1ddfc9421b2c24c948 Mon Sep 17 00:00:00 2001
From: v-jkegler <v-jkegler@microsoft.com>
Date: Tue, 1 Oct 2024 12:19:19 -0400
Subject: [PATCH] Two comments for parser.rs (#21)

Co-authored-by: Jeffrey Kegler <jeffreykegler.notices@protonmail.com>
---
 parser/src/earley/parser.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/parser/src/earley/parser.rs b/parser/src/earley/parser.rs
index 726cb2ce..1e1e934b 100644
--- a/parser/src/earley/parser.rs
+++ b/parser/src/earley/parser.rs
@@ -118,6 +118,11 @@ impl ParserStats {
 struct Row {
     first_item: usize,
     last_item: usize,
+
+    // The "allowed lexemes".  The allowed lexemes (aka acceptable
+    // lexemes, aka relevant lexemes) are those which the recognizer
+    // will accept in the next row.  They are all and only those lexemes
+    // which can lead to a successful parse.
     allowed_lexemes: SimpleVob,
 }
 
@@ -158,8 +163,11 @@ impl Item {
 #[derive(Clone)]
 struct Scratch {
     grammar: Arc<CGrammar>,
+
+    // The current "working row"
     row_start: usize,
     row_end: usize,
+
     items: Vec<Item>,
     item_props: Vec<ItemProps>,
     definitive: bool,