From 5ea76f73d91b06692f421ce931a37622ba95360a Mon Sep 17 00:00:00 2001
From: chirsz-ever <chirsz-ever@outlook.com>
Date: Sun, 17 May 2026 17:28:35 +0800
Subject: [PATCH] Update the ABNF rules for single-line comments

Specify that greedy mode should be used.

Resolve cases where single-line comments end with EOF, LS or PS.
---
 grammar/JSONC.abnf | 5 ++---
 grammar/README.md  | 8 +++++---
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/grammar/JSONC.abnf b/grammar/JSONC.abnf
index e89ae02..87f4886 100644
--- a/grammar/JSONC.abnf
+++ b/grammar/JSONC.abnf
@@ -21,9 +21,8 @@ comment = single-line-comment / multi-line-comment
 ; Single-line comment: starts with //, continues until line ending
 ; Note that the single-line-comment-end is optional, allowing comments to end at the end of the file without a line terminator.
 single-line-comment-start = %x2F.2F             ; // double solidus
-single-line-comment-end = %x0D.0A / %x0A / %x0D
-single-line-comment = single-line-comment-start *single-line-comment-char [ single-line-comment-end ]
-single-line-comment-char = %x00-09 / %x0B-0C / %x0E-10FFFF ; Any source character except CR and LF (line terminator)
+single-line-comment = single-line-comment-start *single-line-comment-char ; Note that this rule should be greedy to consume all characters until the end of the line or the end of the input.
+single-line-comment-char = %x00-09 / %x0B-0C / %x0E-2027 / %x2029-10FFFF ; Any source character except CR, LF, LS and PS (line terminator)
 
 ; Multi-line comment: /* ... */
 ; Cannot be nested. The first */ closes the comment.
diff --git a/grammar/README.md b/grammar/README.md
index af7cd7a..0b8c5fb 100644
--- a/grammar/README.md
+++ b/grammar/README.md
@@ -64,10 +64,12 @@ npm run railroad -- grammar/JSONC.abnf grammar/railroad-diagram.html --title "JS
 
 ### Notes on EOF for single-line comments
 
-The grammar already allows inline comments to terminate at end-of-file because the line terminator is optional:
+The grammar already allows inline comments to terminate at end-of-file because the `single-line-comment` rule does not contain the line terminator:
 
 ```abnf
-single-line-comment = "//" *single-line-comment-char [ comment-terminator ]
+single-line-comment = "//" *single-line-comment-char
 ```
 
-So diagrams generated from this ABNF should not imply a mandatory line ending.
\ No newline at end of file
+ABNF (RFC 5234) does not specify whether greedy matching should be used for repetitive syntax. However, greedy matching is mandatory in the `single-line-comment` rule to ensure correct behavior.
+
+Additionally, when LS (U+2028) or PS (U+2029) appears in a single-line comment, it will end the comment and be used as the next input, thus causing parsing failure as an illegal character.