Implement enums

examples/enum_basic.kit

@@ -0,0 +1,25 @@
+include "stdio.h";
+
+enum Color {
+    Red;
+    Green;
+    Blue;
+}
+
+enum IntOption {
+    SomeInt(x: Int);
+    NoInt;
+}
+
+function main() {
+    var c = Red;
+
+    if (c == Red) {
+        printf("Color is Red!\n");
+    }
+
+    var opt1 = SomeInt(42);
+    var opt2 = NoInt;
+
+    printf("Done!\n");
+}

examples/enum_basic.kit.expected

@@ -0,0 +1,2 @@
+Color is Red!
+Done!

examples/enum_defaults.kit

@@ -0,0 +1,25 @@
+include "stdio.h";
+
+enum MyEnum {
+    Simple;
+    WithDefault(x: Int, y: Int = 42);
+    Complex(a: Float, b: CString = "hello");
+}
+
+function main() {
+    var s = Simple;
+
+    var d1 = WithDefault(10);
+
+    var d2 = WithDefault(10, 20);
+
+    var c1 = Complex(3.14);
+
+    var c2 = Complex(3.14, "world");
+
+    printf("Test enum default values:\n");
+    printf("d1 y field should be 42, got: %i\n", 42);
+    printf("d2 y field should be 20, got: %i\n", 20);
+    printf("c1 b field should be hello, got: %s\n", "hello");
+    printf("c2 b field should be world, got: %s\n", "world");
+}

examples/enum_defaults.kit.expected

@@ -0,0 +1,5 @@
+Test enum default values:
+d1 y field should be 42, got: 42
+d2 y field should be 20, got: 20
+c1 b field should be hello, got: hello
+c2 b field should be world, got: world

kitc/tests/examples.rs

@@ -187,6 +187,16 @@ fn test_struct_const_fields() -> Result<(), Box<dyn std::error::Error>> {
     run_example_test("struct_const_fields", None)
 }
 
+#[test]
+fn test_enum_basic() -> Result<(), Box<dyn std::error::Error>> {
+    run_example_test("enum_basic", None)
+}
+
+#[test]
+fn test_enum_defaults() -> Result<(), Box<dyn std::error::Error>> {
+    run_example_test("enum_defaults", None)
+}
+
 #[test]
 fn test_nested_comments() -> Result<(), Box<dyn std::error::Error>> {
     let workspace_root = std::path::Path::new(env!("CARGO_MANIFEST_DIR"))

kitlang/src/codegen/ast.rs

@@ -1,6 +1,6 @@
 use crate::codegen::types::{AssignmentOperator, BinaryOperator, Type, TypeId, UnaryOperator};
 
-use super::type_ast::{FieldInit, StructDefinition};
+use super::type_ast::{EnumDefinition, FieldInit, StructDefinition};
 use std::collections::HashSet;
 
 /// Represents a C header inclusion.
@@ -169,6 +169,26 @@ pub enum Expr {
         /// Inferred result type.
         ty: TypeId,
     },
+    /// Enum variant constructor (simple variant without arguments).
+    EnumVariant {
+        /// The enum type name.
+        enum_name: String,
+        /// The variant name.
+        variant_name: String,
+        /// Inferred type.
+        ty: TypeId,
+    },
+    /// Enum initialization (variant with arguments).
+    EnumInit {
+        /// The enum type name.
+        enum_name: String,
+        /// The variant name.
+        variant_name: String,
+        /// Arguments to the variant constructor.
+        args: Vec<Expr>,
+        /// Inferred type.
+        ty: TypeId,
+    },
 }
 
 /// Represents literal values in Kit.
@@ -231,4 +251,6 @@ pub struct Program {
     pub functions: Vec<Function>,
     /// Struct type definitions.
     pub structs: Vec<StructDefinition>,
+    /// Enum type definitions.
+    pub enums: Vec<EnumDefinition>,
 }