From 4b3209b65fb4aad2678712c5810e191e19672724 Mon Sep 17 00:00:00 2001
From: Associate 1 <associate_1@code.associates>
Date: Tue, 3 Mar 2026 18:51:52 -0700
Subject: [PATCH] Support *" string escape sequence in lexer

The lexer's readString() did not handle occam's * escape character,
causing *" inside string literals to prematurely terminate the string.
Added escape tracking to match the pattern already used in
readByteLiteral().

Fixes #65

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 codegen/e2e_strings_test.go | 12 ++++++++++++
 lexer/lexer.go              | 14 +++++++++++++-
 lexer/lexer_test2_test.go   | 14 ++++++++++++++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/codegen/e2e_strings_test.go b/codegen/e2e_strings_test.go
index b36f2cd..7eaf6bc 100644
--- a/codegen/e2e_strings_test.go
+++ b/codegen/e2e_strings_test.go
@@ -65,3 +65,15 @@ func TestE2E_StringWithEscapes(t *testing.T) {
 		t.Errorf("expected %q, got %q", expected, output)
 	}
 }
+
+func TestE2E_StringWithEscapedQuote(t *testing.T) {
+	// *" inside a string literal should produce a literal double-quote
+	occam := `SEQ
+  print.string("He said *"hello*"")
+`
+	output := transpileCompileRun(t, occam)
+	expected := "He said \"hello\"\n"
+	if output != expected {
+		t.Errorf("expected %q, got %q", expected, output)
+	}
+}
diff --git a/lexer/lexer.go b/lexer/lexer.go
index be7ab24..30cfd78 100644
--- a/lexer/lexer.go
+++ b/lexer/lexer.go
@@ -303,9 +303,21 @@ func (l *Lexer) readHexNumber() string {
 
 func (l *Lexer) readString() string {
 	position := l.position + 1
+	escaped := false
 	for {
 		l.readChar()
-		if l.ch == '"' || l.ch == 0 {
+		if l.ch == 0 {
+			break
+		}
+		if escaped {
+			escaped = false
+			continue
+		}
+		if l.ch == '*' {
+			escaped = true
+			continue
+		}
+		if l.ch == '"' {
 			break
 		}
 	}
diff --git a/lexer/lexer_test2_test.go b/lexer/lexer_test2_test.go
index 98c81ac..db26727 100644
--- a/lexer/lexer_test2_test.go
+++ b/lexer/lexer_test2_test.go
@@ -161,6 +161,20 @@ func TestStringEscapeSequences(t *testing.T) {
 	}
 }
 
+func TestStringEscapeQuote(t *testing.T) {
+	// *" inside a string should not terminate the string
+	input := `"He said *"hello*""` + "\n"
+	l := New(input)
+	tok := l.NextToken()
+	if tok.Type != STRING {
+		t.Fatalf("expected STRING, got %q", tok.Type)
+	}
+	expected := `He said *"hello*"`
+	if tok.Literal != expected {
+		t.Fatalf("expected literal %q, got %q", expected, tok.Literal)
+	}
+}
+
 func TestByteLiteralToken(t *testing.T) {
 	input := "'A'\n"
 	l := New(input)