[fine] OK

fine/build.rs

@@ -20,7 +20,7 @@ fn generate_test_for_file(path: PathBuf) -> String {
         };
 
         let line = line.trim();
-        if line == "@disabled" {
+        if line == "@ignore" {
             disabled = quote! { #[ignore] };
         } else if line == "@concrete:" {
             let mut concrete = String::new();
@@ -78,6 +78,10 @@ fn generate_test_for_file(path: PathBuf) -> String {
             assertions.push(quote! {
                 crate::assert_type_error_at(&_tree, &_lines, #pos, #expected, #display_path);
             });
+        } else if line == "@no-errors" {
+            assertions.push(quote! {
+                crate::assert_no_errors(&_tree, &_lines);
+            });
         }
     }
 

fine/src/compiler.rs

@@ -219,10 +219,15 @@ pub fn compile(semantics: &Semantics) -> Module {
 fn file(c: &mut Compiler, t: TreeRef) {
     let tree = &c.syntax[t];
     compiler_assert_eq!(c, t, tree.kind, TreeKind::File, "must be compiling a file");
-    for i in 0..tree.children.len() {
-        if let Some(t) = tree.nth_tree(i) {
-            compile_statement(c, t, false);
+
+    let children: Vec<_> = tree.child_trees().collect();
+    if children.len() == 0 {
+        c.push(Instruction::PushNothing);
+    } else {
+        for i in 0..children.len() - 1 {
+            compile_statement(c, children[i], false);
         }
+        compile_statement(c, *children.last().unwrap(), true);
     }
 }
 
@@ -485,18 +490,23 @@ fn compile_if_statement(c: &mut Compiler, tree: &Tree, gen_value: bool) -> CR {
 }
 
 fn compile_expression_statement(c: &mut Compiler, tree: &Tree, gen_value: bool) -> CR {
-    compile_expression(c, tree.nth_tree(0)?);
-    if tree
-        .nth_token(1)
-        .is_some_and(|t| t.kind == TokenKind::Semicolon)
-    {
-        c.push(Instruction::Discard);
-        if gen_value {
-            c.push(Instruction::PushNothing);
+    if let Some(expr) = tree.nth_tree(0) {
+        compile_expression(c, expr);
+
+        if tree
+            .nth_token(1)
+            .is_some_and(|t| t.kind == TokenKind::Semicolon)
+        {
+            c.push(Instruction::Discard);
+            if gen_value {
+                c.push(Instruction::PushNothing);
+            }
+        } else if !gen_value {
+            c.push(Instruction::Discard);
         }
-    } else if !gen_value {
-        c.push(Instruction::Discard);
-    }
+    } else if gen_value {
+        c.push(Instruction::PushNothing);
+    };
 
     OK
 }

fine/src/parser.rs

@@ -641,7 +641,9 @@ fn statement_return(p: &mut CParser) {
 fn statement_expression(p: &mut CParser) {
     let m = p.start();
 
-    expression(p);
+    if !p.at(TokenKind::RightBrace) && !p.at(TokenKind::Semicolon) {
+        expression(p);
+    }
     if !p.at(TokenKind::RightBrace) {
         p.expect(
             TokenKind::Semicolon,

fine/src/semantics.rs

@@ -929,6 +929,18 @@ impl<'a> Semantics<'a> {
 
                 Some(*ret.clone())
             }
+            Type::MagicPrintGarbage => {
+                if arg_types.len() > 1 {
+                    self.report_error_tree(tree, "print takes a single argument");
+                    Some(Type::Error)
+                } else if arg_types.len() == 0 {
+                    Some(Type::Nothing)
+                } else {
+                    let mut arg_types = arg_types;
+                    let (_, t) = arg_types.pop().unwrap();
+                    Some(t)
+                }
+            }
             _ => {
                 self.report_error_tree_ref(f_ref, format!("expected a function type, got: {f}"));
                 Some(Type::Error)

fine/tests/README.md

@@ -37,7 +37,7 @@ e.g., a test might look like this:
 
 The various assertions are as follows:
 
-- The `// @disabled` directive marks the test as ignored.
+- The `// @ignore` directive marks the test as ignored.
 
 - The `// @concrete:` assertion says that the following lines
   (prefixed with `// | `, as above) describe the concrete syntax tree

fine/tests/example_tests.rs

@@ -1,6 +1,6 @@
 use fine::compiler::{compile, Function, Module};
 use fine::parser::SyntaxTree;
-use fine::semantics::{Semantics, Type};
+use fine::semantics::{check, Error, Semantics, Type};
 use fine::tokens::Lines;
 use pretty_assertions::assert_eq;
 use std::fmt::Write as _;
@@ -243,4 +243,19 @@ fn assert_compiles_to(tree: &SyntaxTree, lines: &Lines, expected: &str, source_p
     }
 }
 
+fn assert_no_errors(tree: &SyntaxTree, lines: &Lines) {
+    let semantics = Semantics::new(tree, lines);
+    check(&semantics);
+
+    let expected_errors: Vec<Error> = Vec::new();
+    let errors = semantics.snapshot_errors();
+    semantic_assert_eq!(
+        &semantics,
+        None,
+        expected_errors,
+        errors,
+        "expected no errors"
+    );
+}
+
 include!(concat!(env!("OUT_DIR"), "/generated_tests.rs"));

fine/tests/expression/argument.fine

@@ -36,5 +36,6 @@ fun foo(x: f64) {
 // |     2: FloatAdd
 // | function << module >> (0 args, 0 locals):
 // |   strings (0):
-// |   code (0):
+// |   code (1):
+// |     0: PushNothing
 // |

fine/tests/expression/arithmetic.fine

@@ -25,7 +25,7 @@
 // @compiles-to:
 // | function << module >> (0 args, 0 locals):
 // |   strings (0):
-// |   code (10):
+// |   code (11):
 // |     0: PushFloat(1.0)
 // |     1: PushFloat(2.0)
 // |     2: FloatMultiply
@@ -36,4 +36,5 @@
 // |     7: FloatMultiply
 // |     8: FloatAdd
 // |     9: Discard
+// |     10: PushNothing
 // |

fine/tests/expression/empty_statement.fine

@@ -1,5 +1,14 @@
-// @disabled
-// @concrete:
-// |
-
 ;
+
+// @no-errors
+// @concrete:
+// | File
+// |   ExpressionStatement
+// |     Semicolon:'";"'
+// |
+// @compiles-to:
+// | function << module >> (0 args, 0 locals):
+// |   strings (0):
+// |   code (1):
+// |     0: PushNothing
+// |

fine/tests/expression/variable.fine

@@ -3,6 +3,7 @@ let y = x * 2;
 let z = print(y);
 z;
 
+// @no-errors
 // @type: 41 f64
 // @concrete:
 // | File
@@ -46,7 +47,7 @@ z;
 // @compiles-to:
 // | function << module >> (0 args, 0 locals):
 // |   strings (0):
-// |   code (12):
+// |   code (13):
 // |     0: PushFloat(23.0)
 // |     1: StoreModule(0)
 // |     2: LoadModule(0)
@@ -59,4 +60,5 @@ z;
 // |     9: StoreModule(2)
 // |     10: LoadModule(2)
 // |     11: Discard
+// |     12: PushNothing
 // |