From fa732617fbc01b16a6d3c561858bd2a95467c074 Mon Sep 17 00:00:00 2001
From: Taylor Holliday <wtholliday@gmail.com>
Date: Sat, 8 Aug 2026 14:46:42 -0700
Subject: [PATCH] Allow semicolons to separate statements

Statements in a block could only be separated by newlines. Accept `;` as
an alternate separator so multiple statements can share a line.

The lexer already produced Token::Semi for array types (`[T; N]`) and
array repeat literals (`[x; n]`); those are distinct contexts and are
unaffected. A semicolon is now accepted anywhere a newline was, including
trailing before the closing brace. Since parse_block is shared, this
covers function bodies, while/for bodies, if/else branches, and block
expressions.

The semicolon is purely a separator: unlike Rust, a trailing one does not
void the block's value, so `{ a; b; }` still evaluates to `b`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QL98e281ffpSW7JKQyS87C
---
 src/parser.rs               | 10 +++++++++-
 tests/cases/semicolons.lyte | 25 +++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/semicolons.lyte

diff --git a/src/parser.rs b/src/parser.rs
index 34fa005..878725b 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -853,7 +853,9 @@ fn parse_block(arena: &mut ExprArena, typevars: &[Name], cx: &mut ParseContext)
 
         r.push(parse_stmt(arena, typevars, cx));
 
-        if cx.lex.tok != Token::Endl {
+        // Statements are separated by newlines or semicolons. Semicolons let
+        // multiple statements share a line.
+        if cx.lex.tok != Token::Endl && cx.lex.tok != Token::Semi {
             break;
         }
 
@@ -1461,6 +1463,12 @@ mod tests {
                 "{ x = y\n z = w }",
                 "{ f(x)\n g(y) }",
                 "{ var x = y\n var z = w }",
+                "{ x; y }",
+                "{ x; }",
+                "{ x;\n y }",
+                "{ x = y; z = w }",
+                "{ var x = y; var z = w; f(x) }",
+                "{ while x { y; z }; w }",
             ],
         );
     }
diff --git a/tests/cases/semicolons.lyte b/tests/cases/semicolons.lyte
new file mode 100644
index 0000000..2927880
--- /dev/null
+++ b/tests/cases/semicolons.lyte
@@ -0,0 +1,25 @@
+// expected stdout:
+// compilation successful
+// assert(true)
+// assert(true)
+// assert(true)
+// assert(true)
+
+sum_three(a: i32, b: i32, c: i32) -> i32 {
+    var t = 0; t = t + a; t = t + b
+    t = t + c
+    return t
+}
+
+main {
+    var x = 1; var y = 2; var z = x + y
+    assert(z == 3)
+
+    // Trailing semicolon before the closing brace.
+    assert(sum_three(1, 2, 3) == 6);
+
+    var i = 0
+    while i < 3 { i = i + 1; x = x + i }
+    assert(i == 3)
+    assert(x == 7)
+}