Implement unary operators as syntax sugar

README.md

@@ -38,11 +38,11 @@ Currently missing big features (TODOs) are:
 - ~~Extern functions~~ (DONE)
 - ~~Strings~~ (DONE)
 - ~~Borrows~~ (DONE)
-- ~~Pointers~~
+- ~~Pointers~~ (DONE)
+- Unary operators
+- Floats
 - Loops
 - Debug Information (PARTIALLY DONE)
-- Floats
-- Unary operators
 - Ability to specify types in literals and variable definitions
 
 Big features that I want later but are not necessary:

reid/src/ast/mod.rs

@@ -57,6 +57,13 @@ pub enum ExpressionKind {
     BlockExpr(Box<Block>),
     IfExpr(Box<IfExpression>),
     StructExpression(StructExpression),
+    UnaryOperation(UnaryOperator, Box<Expression>),
+}
+
+#[derive(Debug, Clone)]
+pub enum UnaryOperator {
+    Plus,
+    Minus,
 }
 
 #[derive(Debug, Clone, Copy)]

reid/src/ast/parse.rs

@@ -72,6 +72,20 @@ impl Parse for Expression {
     }
 }
 
+impl Parse for UnaryOperator {
+    fn parse(mut stream: TokenStream) -> Result<Self, Error> {
+        if let Some(token) = stream.next() {
+            match token {
+                Token::Plus => Ok(UnaryOperator::Plus),
+                Token::Minus => Ok(UnaryOperator::Minus),
+                _ => Err(stream.expected_err("unary operator")?),
+            }
+        } else {
+            Err(stream.expected_err("unary operator")?)
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct PrimaryExpression(Expression);
 
@@ -117,6 +131,11 @@ impl Parse for PrimaryExpression {
             stream.next(); // Consume Et
             stream.next(); // Consume identifier
             Expression(Kind::Deref(name), stream.get_range().unwrap())
+        } else if let Ok(unary) = stream.parse() {
+            Expression(
+                Kind::UnaryOperation(unary, Box::new(stream.parse()?)),
+                stream.get_range().unwrap(),
+            )
         } else if let Some(token) = stream.next() {
             match &token {
                 Token::Identifier(v) => {

reid/src/ast/process.rs

@@ -238,6 +238,24 @@ impl ast::Expression {
                 name.clone(),
                 self.1.as_meta(module_id),
             )),
+            ast::ExpressionKind::UnaryOperation(unary_operator, expr) => match unary_operator {
+                ast::UnaryOperator::Plus => mir::ExprKind::BinOp(
+                    mir::BinaryOperator::Add,
+                    Box::new(mir::Expression(
+                        mir::ExprKind::Literal(mir::Literal::Vague(mir::VagueLiteral::Number(0))),
+                        expr.1.as_meta(module_id),
+                    )),
+                    Box::new(expr.process(module_id)),
+                ),
+                ast::UnaryOperator::Minus => mir::ExprKind::BinOp(
+                    mir::BinaryOperator::Minus,
+                    Box::new(mir::Expression(
+                        mir::ExprKind::Literal(mir::Literal::Vague(mir::VagueLiteral::Number(0))),
+                        expr.1.as_meta(module_id),
+                    )),
+                    Box::new(expr.process(module_id)),
+                ),
+            },
         };
 
         mir::Expression(kind, self.1.as_meta(module_id))

reid/src/mir/linker.rs

@@ -103,10 +103,10 @@ impl<'map> Pass for LinkerPass<'map> {
             modules.insert(module.name.clone(), Rc::new(RefCell::new((module, tokens))));
         }
 
-        // modules.insert(
-        //     "std".to_owned(),
-        //     Rc::new(RefCell::new(compile_std(&mut self.module_map)?)),
-        // );
+        modules.insert(
+            "std".to_owned(),
+            Rc::new(RefCell::new(compile_std(&mut self.module_map)?)),
+        );
 
         let mut modules_to_process: Vec<Rc<RefCell<(Module, Vec<FullToken>)>>> =
             modules.values().cloned().collect();

reid_src/arithmetic.reid

@@ -5,5 +5,5 @@ fn main() -> u32 {
   let value = 6;
   let other = 15;
 
-  return value * other + 7 * value;
+  return value * other + 7 * (-value);
 }