From a2dd73409b4808a784e1bebde85a6cdb3ef10274 Mon Sep 17 00:00:00 2001
From: Jay Hemnani <193022578+jayhemnani9910@users.noreply.github.com>
Date: Sat, 24 Oct 2026 02:28:43 +0530
Subject: [PATCH 1/2] lexer: read / after a built-in variable as division

---
 lexer/src/lib.rs          | 42 +++++++++++++++++++--------------------
 tests/by-util/test_awk.rs |  9 +++++++++
 2 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/lexer/src/lib.rs b/lexer/src/lib.rs
index d7eabad..5c82dae 100644
--- a/lexer/src/lib.rs
+++ b/lexer/src/lib.rs
@@ -183,47 +183,47 @@ pub enum Token<'a> {
     Lshift,
     #[token("rshift", |lex| parse_non_posix_keyword(lex, Token::Rshift))]
     Rshift,
-    #[regex("(awk::)?NR", accept_expression)]
+    #[regex("(awk::)?NR", accept_operator)]
     NrVariable,
-    #[regex("(awk::)?NF", accept_expression)]
+    #[regex("(awk::)?NF", accept_operator)]
     NfVariable,
-    #[regex("(awk::)?FS", accept_expression)]
+    #[regex("(awk::)?FS", accept_operator)]
     FsVariable,
-    #[regex("(awk::)?FPAT", accept_expression)]
+    #[regex("(awk::)?FPAT", accept_operator)]
     FpatVariable,
-    #[regex("(awk::)?FIELDWIDTHS", accept_expression)]
+    #[regex("(awk::)?FIELDWIDTHS", accept_operator)]
     FieldwidthsVariable,
-    #[regex("(awk::)?RS", accept_expression)]
+    #[regex("(awk::)?RS", accept_operator)]
     RsVariable,
-    #[regex("(awk::)?OFS", accept_expression)]
+    #[regex("(awk::)?OFS", accept_operator)]
     OfsVariable,
-    #[regex("(awk::)?ORS", accept_expression)]
+    #[regex("(awk::)?ORS", accept_operator)]
     OrsVariable,
-    #[regex("(awk::)?FILENAME", accept_expression)]
+    #[regex("(awk::)?FILENAME", accept_operator)]
     FilenameVariable,
-    #[regex("(awk::)?ARGC", accept_expression)]
+    #[regex("(awk::)?ARGC", accept_operator)]
     ArgcVariable,
-    #[regex("(awk::)?ARGV", accept_expression)]
+    #[regex("(awk::)?ARGV", accept_operator)]
     ArgvVariable,
-    #[regex("(awk::)?SUBSEP", accept_expression)]
+    #[regex("(awk::)?SUBSEP", accept_operator)]
     SubsepVariable,
-    #[regex("(awk::)?FNR", accept_expression)]
+    #[regex("(awk::)?FNR", accept_operator)]
     FnrVariable,
-    #[regex("(awk::)?ARGIND")]
+    #[regex("(awk::)?ARGIND", accept_operator)]
     ArgindVariable,
-    #[regex("(awk::)?OFMT", accept_expression)]
+    #[regex("(awk::)?OFMT", accept_operator)]
     OfmtVariable,
-    #[regex("(awk::)?RSTART", accept_expression)]
+    #[regex("(awk::)?RSTART", accept_operator)]
     RstartVariable,
-    #[regex("(awk::)?RLENGTH", accept_expression)]
+    #[regex("(awk::)?RLENGTH", accept_operator)]
     RlengthVariable,
-    #[regex("(awk::)?ENVIRON", accept_expression)]
+    #[regex("(awk::)?ENVIRON", accept_operator)]
     EnvironVariable,
-    #[regex("(awk::)?PROCINFO", accept_expression)]
+    #[regex("(awk::)?PROCINFO", accept_operator)]
     ProcinfoVariable,
-    #[regex("(awk::)?SYMTAB", accept_expression)]
+    #[regex("(awk::)?SYMTAB", accept_operator)]
     SymtabVariable,
-    #[regex("(awk::)?FUNCTAB", accept_expression)]
+    #[regex("(awk::)?FUNCTAB", accept_operator)]
     FunctabVariable,
     #[regex("(?&identifier)", Identifier::parse::<0>)]
     Identifier(Identifier<'a>),
diff --git a/tests/by-util/test_awk.rs b/tests/by-util/test_awk.rs
index 9f56c9f..75e019c 100644
--- a/tests/by-util/test_awk.rs
+++ b/tests/by-util/test_awk.rs
@@ -899,3 +899,12 @@ fn bare_regex_in_expression_matches_record() {
         .succeeds()
         .stdout_is("y 2\n2\n");
 }
+
+#[test]
+fn slash_after_special_variable_divides() {
+    ucmd()
+        .arg("{ print NR / 2, NF/NR } END { RSTART = 8; print RSTART / 2 / 2 }")
+        .pipe_in("a b\nc d\n")
+        .succeeds()
+        .stdout_only("0.5 2\n1 1\n2\n");
+}

From f15885cc72635f2df69db56a15b311581d7c0e3a Mon Sep 17 00:00:00 2001
From: Jay Hemnani <193022578+jayhemnani9910@users.noreply.github.com>
Date: Sun, 25 Oct 2026 00:15:14 +0530
Subject: [PATCH 2/2] tests: cover NR /= after a built-in variable

---
 lexer/src/tests.rs        | 5 ++++-
 tests/by-util/test_awk.rs | 4 ++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/lexer/src/tests.rs b/lexer/src/tests.rs
index c998bca..f7c6228 100644
--- a/lexer/src/tests.rs
+++ b/lexer/src/tests.rs
@@ -241,13 +241,16 @@ fn lexer_test_general_tokens() {
 fn lexer_test_regex_ambiguity() {
     let arena = Bump::new();
     assert_eq!(
-        &lex(b"1/=1. a/=1", &arena, false, false),
+        &lex(b"1/=1. a/=1 NR/=1", &arena, false, false),
         &[
             Token::Integer(1),
             Token::SlashAssign,
             Token::Number(1.),
             Token::Identifier(Identifier { literal: "a" }),
             Token::SlashAssign,
+            Token::Integer(1),
+            Token::NrVariable,
+            Token::SlashAssign,
             Token::Integer(1)
         ]
     );
diff --git a/tests/by-util/test_awk.rs b/tests/by-util/test_awk.rs
index 75e019c..9571365 100644
--- a/tests/by-util/test_awk.rs
+++ b/tests/by-util/test_awk.rs
@@ -903,8 +903,8 @@ fn bare_regex_in_expression_matches_record() {
 #[test]
 fn slash_after_special_variable_divides() {
     ucmd()
-        .arg("{ print NR / 2, NF/NR } END { RSTART = 8; print RSTART / 2 / 2 }")
+        .arg("{ print NR / 2, NF/NR } END { RSTART = 8; print RSTART / 2 / 2; NR = 6; NR /= 2; print NR }")
         .pipe_in("a b\nc d\n")
         .succeeds()
-        .stdout_only("0.5 2\n1 1\n2\n");
+        .stdout_only("0.5 2\n1 1\n2\n3\n");
 }