[fine] Fix block compilation

fine/src/compiler.rs

@@ -477,6 +477,11 @@ fn compile_call_expression(c: &mut Compiler, tree: &Tree) -> CR {
 }
 
 fn compile_block_expression(c: &mut Compiler, tree: &Tree) -> CR {
+    if tree.children.len() == 2 {
+        c.push(Instruction::PushNothing);
+        return OK;
+    }
+
     let last_is_brace = tree.nth_token(tree.children.len() - 1).is_some();
     let last_index = tree.children.len() - if last_is_brace { 2 } else { 1 };
 
@@ -499,6 +504,7 @@ fn compile_statement(c: &mut Compiler, t: TreeRef, gen_value: bool) {
         TreeKind::LetStatement => compile_let_statement(c, t, tree, gen_value),
         TreeKind::ExpressionStatement => compile_expression_statement(c, tree, gen_value),
         TreeKind::IfStatement => compile_if_statement(c, tree, gen_value),
+        TreeKind::Block => compile_block_statement(c, t, gen_value),
         _ => ice!(c, t, "unsupported tree kind {:?}", tree.kind),
     };
     if matches!(cr, None) {
@@ -607,3 +613,12 @@ fn compile_function_declaration(c: &mut Compiler, t: TreeRef, tree: &Tree, gen_v
 
     OK
 }
+
+fn compile_block_statement(c: &mut Compiler, t: TreeRef, gen_value: bool) -> CR {
+    compile_expression(c, t);
+    if !gen_value {
+        c.push(Instruction::Discard);
+    }
+
+    OK
+}

fine/tests/expression/arithmetic.fine

@@ -1,9 +1,20 @@
-1 * 2 + -3 * 4;
+fun test() {
+    1 * 2 + -3 * 4
+}
 
 // @no-errors
-// @type: 6 f64
+// @eval: Float(-10.0)
+// @type: 23 f64
 // @concrete:
 // | File
+// |   FunctionDecl
+// |     Fun:'"fun"'
+// |     Identifier:'"test"'
+// |     ParamList
+// |       LeftParen:'"("'
+// |       RightParen:'")"'
+// |     Block
+// |       LeftBrace:'"{"'
 // |       ExpressionStatement
 // |         BinaryExpression
 // |           BinaryExpression
@@ -21,12 +32,12 @@
 // |             Star:'"*"'
 // |             LiteralExpression
 // |               Number:'"4"'
-// |     Semicolon:'";"'
+// |       RightBrace:'"}"'
 // |
 // @compiles-to:
-// | function << module >> (0 args, 0 locals):
+// | function test (0 args, 0 locals):
 // |   strings (0):
-// |   code (12):
+// |   code (10):
 // |     0: PushFloat(1.0)
 // |     1: PushFloat(2.0)
 // |     2: FloatMultiply
@@ -36,7 +47,10 @@
 // |     6: PushFloat(4.0)
 // |     7: FloatMultiply
 // |     8: FloatAdd
-// |     9: Discard
+// |     9: Return
-// |     10: PushNothing
+// | function << module >> (0 args, 0 locals):
-// |     11: Return
+// |   strings (0):
+// |   code (2):
+// |     0: PushNothing
+// |     1: Return
 // |

fine/tests/expression/block.fine

@@ -1,10 +1,34 @@
+fun test() {
   {}
+}
 
 // @no-errors
-// @type: 0 ()
+// @compiles-to:
+// | function test (0 args, 0 locals):
+// |   strings (0):
+// |   code (2):
+// |     0: PushNothing
+// |     1: Return
+// | function << module >> (0 args, 0 locals):
+// |   strings (0):
+// |   code (2):
+// |     0: PushNothing
+// |     1: Return
+// |
+// @eval: Nothing
+// @type: 15 ()
 // @concrete:
 // | File
+// |   FunctionDecl
+// |     Fun:'"fun"'
+// |     Identifier:'"test"'
+// |     ParamList
+// |       LeftParen:'"("'
+// |       RightParen:'")"'
+// |     Block
+// |       LeftBrace:'"{"'
 // |       Block
 // |         LeftBrace:'"{"'
 // |         RightBrace:'"}"'
+// |       RightBrace:'"}"'
 // |