...

compiler/Compiler/Generator.cs

@@ -185,10 +185,11 @@ public sealed class Generator(List<NodeDefinition> nodes)
         return node switch
         {
             NodeExpressionBinary expression => EmitExpressionBinary(expression),
+            NodeExpressionUnary expression => EmitExpressionUnary(expression),
             NodeExpressionBoolLiteral expression => expression.Value.Value ? "true" : "false",
             NodeExpressionIntLiteral expression => expression.Value.Value.ToString(),
             NodeExpressionStringLiteral expression => $"(struct string){{ \"{expression.Value.Value}\", {expression.Value.Value.Length} }}",
-            NodeExpressionStructLiteral expression => EmitStructLiteral(expression),
+            NodeExpressionStructLiteral expression => EmitExpressionStructLiteral(expression),
             NodeExpressionMemberAccess expression => EmitExpressionMemberAccess(expression),
             NodeExpressionIdent expression => expression.Value.Ident,
             _ => throw new ArgumentOutOfRangeException(nameof(node), node, null)
@@ -221,23 +222,19 @@ public sealed class Generator(List<NodeDefinition> nodes)
         };
     }
 
-    private static string CType(NodeType node, string? varName = null)
+    private string EmitExpressionUnary(NodeExpressionUnary expression)
     {
-        return node switch
+        var target = EmitExpression(expression.Target);
+
+        return expression.Operation switch
         {
-            NodeTypeVoid => "void" + (varName != null ? $" {varName}" : ""),
+            NodeExpressionUnary.Op.Negate => $"(-{target})",
-            NodeTypeBool => "bool" + (varName != null ? $" {varName}" : ""),
+            NodeExpressionUnary.Op.Invert => $"(!{target})",
-            NodeTypeCustom type => $"struct {type.Name.Ident}" + (varName != null ? $" {varName}" : ""),
+            _ => throw new ArgumentOutOfRangeException()
-            NodeTypeSInt type => $"int{type.Width}_t" + (varName != null ? $" {varName}" : ""),
-            NodeTypeUInt type => $"uint{type.Width}_t" + (varName != null ? $" {varName}" : ""),
-            NodeTypePointer type => CType(type.To) + (varName != null ? $" *{varName}" : "*"),
-            NodeTypeString => "struct string" + (varName != null ? $" {varName}" : ""),
-            NodeTypeFunc type => $"{CType(type.ReturnType)} (*{varName})({string.Join(", ", type.Parameters.Select(p => CType(p)))})",
-            _ => throw new ArgumentOutOfRangeException(nameof(node), node, null)
         };
     }
 
-    private string EmitStructLiteral(NodeExpressionStructLiteral expression)
+    private string EmitExpressionStructLiteral(NodeExpressionStructLiteral expression)
     {
         var initializerValues = new Dictionary<string, string>();
 
@@ -257,6 +254,22 @@ public sealed class Generator(List<NodeDefinition> nodes)
         var target = EmitExpression(expression.Target);
         return $"{target}.{expression.Name.Ident}";
     }
+
+    private static string CType(NodeType node, string? varName = null)
+    {
+        return node switch
+        {
+            NodeTypeVoid => "void" + (varName != null ? $" {varName}" : ""),
+            NodeTypeBool => "bool" + (varName != null ? $" {varName}" : ""),
+            NodeTypeCustom type => $"struct {type.Name.Ident}" + (varName != null ? $" {varName}" : ""),
+            NodeTypeSInt type => $"int{type.Width}_t" + (varName != null ? $" {varName}" : ""),
+            NodeTypeUInt type => $"uint{type.Width}_t" + (varName != null ? $" {varName}" : ""),
+            NodeTypePointer type => CType(type.To) + (varName != null ? $" *{varName}" : "*"),
+            NodeTypeString => "struct string" + (varName != null ? $" {varName}" : ""),
+            NodeTypeFunc type => $"{CType(type.ReturnType)} (*{varName})({string.Join(", ", type.Parameters.Select(p => CType(p)))})",
+            _ => throw new ArgumentOutOfRangeException(nameof(node), node, null)
+        };
+    }
 }
 
 internal class IndentedTextWriter

compiler/Compiler/Parser.cs

@@ -208,6 +208,16 @@ public sealed class Parser(string fileName, List<Token> tokens)
             ExpectSymbol(Symbol.CloseParen);
             expr = value;
         }
+        else if (TryExpectSymbol(Symbol.Minus))
+        {
+            var target = ParseExpression();
+            expr = new NodeExpressionUnary(TokensFrom(startIndex), target, NodeExpressionUnary.Op.Negate);
+        }
+        else if (TryExpectSymbol(Symbol.Bang))
+        {
+            var target = ParseExpression();
+            expr = new NodeExpressionUnary(TokensFrom(startIndex), target, NodeExpressionUnary.Op.Invert);
+        }
         else if (TryExpectIntLiteral(out var intLiteral))
         {
             expr = new NodeExpressionIntLiteral(TokensFrom(startIndex), intLiteral);
@@ -617,7 +627,6 @@ public sealed class NodeExpressionBinary(List<Token> tokens, NodeExpression left
     public readonly Op Operation = operation;
     public readonly NodeExpression Right = right;
 
-
     public enum Op
     {
         Add,
@@ -645,6 +654,18 @@ public sealed class NodeExpressionBinary(List<Token> tokens, NodeExpression left
     }
 }
 
+public sealed class NodeExpressionUnary(List<Token> tokens, NodeExpression target, NodeExpressionUnary.Op op) : NodeExpression(tokens)
+{
+    public NodeExpression Target { get; } = target;
+    public Op Operation { get; } = op;
+
+    public enum Op
+    {
+        Negate,
+        Invert,
+    }
+}
+
 public abstract class NodeType(List<Token> tokens) : Node(tokens);
 
 public sealed class NodeTypeVoid(List<Token> tokens) : NodeType(tokens);

compiler/Compiler/test.nub

@@ -7,8 +7,9 @@ func main(): i32 {
     let x: i32 = 23
     x = 24
     
-    if true {
+    if !true {
         x = 49
+        return x
     } else {
         x = 3
     }