Type match statement for tagged unions

examples/demo.odin

@@ -4,20 +4,758 @@
 
 main :: proc() {
 	Entity :: type union {
-		FROG: struct {
+		Frog: struct {
 			jump_height: f32
 		}
-		HELICOPTER: struct {
+		Helicopter: struct {
 			weight:     f32
 			blade_code: int
 		}
 	}
 
-	e: Entity
-	f: Entity = Entity.FROG{1};
-	h: Entity = Entity.HELICOPTER{123, 4};
+	using Entity
+	f: Entity = Frog{137}
+	h: Entity = Helicopter{123, 4}
 
+	match type ^f -> e {
+	case Frog:
+		print_string("Frog!\n")
+		print_f32(e.jump_height); nl()
+		e.jump_height = 69
+		print_f32(e.jump_height); nl()
+	case Helicopter:
+		print_string("Helicopter!\n")
+		e.weight = 1337
+	default:
+		print_string("Unknown!\n")
+	}
 }
 
 nl :: proc() { print_nl() }
 
+/*
+// Demo 001
+#load "basic.odin"
+#load "game.odin"
+
+main :: proc() {
+	// _ = hellope()
+	// procedures()
+	// variables()
+	// constants()
+	// types()
+	// data_control()
+	// using_fields()
+
+	run_game()
+}
+
+
+hellope :: proc() -> int {
+	print_string("Hellope, 世界\n")
+	return 1
+}
+
+
+// Line comment
+/*
+	Block Comment
+*/
+/*
+	Nested /*
+		Block /*
+			Comment
+		*/
+	*/
+*/
+
+apple, banana, carrot: bool
+box, carboard: bool = true, false
+// hellope_value: int = hellope() // The procedure is ran just before `main`
+
+variables :: proc() {
+	i: int // initialized with zero value
+	j: int = 1
+	x, y: int = 1, 2
+
+	// Type inference
+	apple, banana, 世界 := true, 123, "world"
+
+
+	// Basic Types of the Language
+	//
+	// bool
+	//
+	// i8 i16 i32 i64 i128
+	// u8 u16 u32 u64 u128
+	//
+	// f32 f64
+	//
+	// int uint (size_of(int) == size_of(uint) == size_of(rawptr))
+	//
+	// rawptr (equivalent to void * in C/C++)
+	//
+	// string
+	//
+	// byte - alias for u8
+	// rune - alias for i32 // Unicode Codepoint
+	//
+	// "untyped" types can implicitly convert to any of the "typed" types
+	//                      Default Type
+	// untyped bool      -  bool
+	// untyped integer   -  int
+	// untyped float     -  f64
+	// untyped pointer   -  rawptr
+	// untyped string    -  string
+	// untyped rune      -  rune/i32
+
+
+	// Zero values
+	zero_numeric := 0
+	zero_boolean := false
+	zero_pointer := null
+	zero_string1 := "" // Escaped string
+	zero_string2 := `` // Raw string
+	// Compound types have a different kind of zero value
+
+	// Unary operators
+	// +a
+	// -a
+	// ~a
+	// !a
+
+	// Binary operators
+	// a + b    add
+	// a - b    sub
+	// a ~ b    xor
+	// a | b     or
+
+	// a * b    mul
+	// a / b    quo
+	// a % b    mod
+	// a & b    and
+	// a &~ b   bitclear == a & (~b)
+	// a << b   shl
+	// a >> b   shr
+
+	// a as Type         // Type cast
+	// a transmute Type  // Bit  cast
+
+	// a == b   eq
+	// a != b   ne
+	// a < b    lt
+	// a > b    gt
+	// a <= b   le
+	// a >= b   ge
+
+}
+
+procedures :: proc() {
+	add :: proc(x: int, y: int) -> int {
+		return x + y
+	}
+	print_int(add(3, 4)) // 7
+	print_nl()
+
+	add_v2 :: proc(x, y: int) -> int {
+		return x + y
+	}
+
+	fibonacci :: proc(n: int) -> int {
+		if n < 2 {
+			return n
+		}
+		return fibonacci(n-1) + fibonacci(n-2)
+	}
+	print_int(fibonacci(12)); nl()
+
+
+	swap_strings :: proc(x, y: string) -> (string, string) {
+		return y, x
+	}
+	a, b := swap_strings("Hellope\n", "World\n")
+	print_string(a)
+	print_string(b)
+
+	a, b = b, a // Quirk of grammar the of multiple assignments
+	             // Swap variables
+	print_string(a)
+	print_string(b)
+
+	// Not a hint like C/C++, it's mandatory (unless it cannot do it but it will warn)
+	proc1 :: proc(a, b: int) #inline {
+		print_int(a + b)
+	}
+	proc2 :: proc(a, b: int) #no_inline {
+		print_int(a + b)
+	}
+
+	print_int(3 ''add 4)     // Infix style
+	print_nl()
+	print_int(12 'fibonacci) // Postfix style
+	print_nl()
+}
+
+
+TAU :: 6.28318530718
+
+constants :: proc() {
+	TAU :: 6.28318530718 // untyped float
+	WORLD_JAPANESE :: "世界" // untyped string
+
+	TAU_32 : f32 : 6.28318530718
+	TAU_AS_32 :: 6.28318530718 as f32
+
+	PI :: TAU / 2
+
+	CLOSE_TO_PI :: 3
+
+	DIFF :: (PI - CLOSE_TO_PI) / PI // Evaluated at compile time
+
+	a := TAU         // the constant's value becomes typed as f32
+	b := CLOSE_TO_PI // the constant's value becomes typed as int
+	c := DIFF
+}
+
+nl :: proc() { print_nl() }
+
+types :: proc() {
+
+	x: int = 123
+	y := x // y: int = x
+	// z: f32 = x // invalid
+	z: f32 = x as f32
+
+
+	ptr_z := ^z  // Pascal notation
+	ptr_z^ = 123 // Derefence Notation
+	w: f32 = ptr_z^  // 123
+	print_f32(z); nl()
+
+	// ^z - pointer to z
+	// z^ - z from pointer
+
+	// Implicit conversion to and from rawptr
+	r_ptr: rawptr = ptr_z
+	ptr_z = r_ptr
+
+
+
+
+	f32_array: [12]f32 // Array of 12 f32
+	f32_array[0] = 2
+	f32_array[1] = 3
+	// f32_array[-1] = 2 // Error - compile time check
+	// f32_array[13]  = 2 // Error - compile time check
+	f32_array_len := len(f32_array) // builtin procedure
+	f32_array_cap := cap(f32_array) // == len(f32_array)
+
+
+	mda: [2][3][4]int // Column-major
+	// mda[x][y][z]
+
+
+
+	api: [2]^f32
+	papi: ^[2]^f32
+
+
+
+
+	f32_slice: []f32 // Slice / Array reference
+	f32_slice = f32_array[0:5]
+	f32_slice = f32_array[:5]
+	f32_slice = f32_array[:] // f32_array[0:len(f32_array)-1]
+
+	f32_slice = f32_array[1:5:7] // low:1, high:5, max:7
+	                              // len: 5-1 == 4
+	                              // cap: 7-1 == 6
+
+
+
+	append_success := append(^f32_slice, 1)
+	_ = append(^f32_slice, 2)
+
+	_ = copy(f32_array[0:2], f32_array[2:4]) // You can use memcpy/memmove if you want
+
+
+
+
+
+
+	s := "Hellope World"
+	sub_string: string = s[5:10]
+
+
+
+
+
+	v0: {4}f32 // Vector of 4 f32
+	v0[0] = 1
+	v0[1] = 3
+	v0[2] = 6
+	v0[3] = 10
+
+	v1 := v0 + v0 // Simd Arithmetic
+	v1 = v1 - v0
+	v1 *= v0 // i.e. hadamard product
+	v1 /= v0
+
+	// builtin procedure
+	v2 := swizzle(v0, 3, 2, 1, 0) // {10, 6, 3, 1}
+
+	v3: {4}bool = v0 == v2
+	// LLVM rant?
+
+
+
+
+
+
+
+	Vec4 :: type {4}f32
+	Array3Int :: type [3]int
+
+	Vec3 :: type struct {
+		x, y, z: f32
+	}
+
+	BinaryNode :: type struct {
+		left, right: ^BinaryNode // same format as procedure argument
+		data: rawptr
+	}
+
+	AddProc :: type proc(a, b: int) -> int
+
+	Packed :: type struct #packed {
+		a: u8
+		b: u16
+		c: u32
+	}
+	assert(size_of(Packed) == 7) // builtin procedure
+	{
+		a, b: ^BinaryNode
+		a = alloc(size_of(BinaryNode)) as ^BinaryNode
+		b = alloc(size_of(BinaryNode)) as ^BinaryNode
+
+		c := BinaryNode{a, b, null}
+		c.left^.data = null
+		c.left.data = null // No need to deference
+
+		dealloc(a)
+		dealloc(b)
+	}
+
+	{
+		MyInt :: type int
+		x: int = 1
+		y: MyInt = 2
+		// z := x + y // Failure - types cannot implicit convert*
+		z := x as MyInt + y // Type cast using `as`
+	}
+
+
+	{
+		// From: Quake III Arena
+		Q_rsqrt :: proc(number: f32) -> f32 {
+			i: i32
+			x2, y: f32
+			THREE_HALFS :: 1.5
+
+			x2 = number * 0.5
+			y = number
+			i = (^y as ^i32)^                      // evil floating point bit level hacking
+			i = 0x5f3759df - i>>1                  // what the fuck?
+			y = (^i as ^f32)^
+			y = y * (THREE_HALFS - (x2 * y *y))    // 1st iteration
+		//	y = y * (THREE_HALFS - (x2 * y *y))    // 2nd iteration, this can be removed
+			return y
+		}
+
+		Q_rsqrt_v2 :: proc(number: f32) -> f32 {
+			THREE_HALFS :: 1.5
+
+			x2 := number * 0.5
+			y := number
+			i := y transmute i32                   // evil floating point bit level hacking
+			i = 0x5f3759df - i>>1                  // what the fuck?
+			y = i transmute f32
+			y = y * (THREE_HALFS - (x2 * y *y))    // 1st iteration
+		//	y = y * (THREE_HALFS - (x2 * y *y))    // 2nd iteration, this can be removed
+			return y
+		}
+
+		// NOTE(bill): transmute only works if the size of the types are equal
+
+		/*
+			// in C
+			union {
+				i32 i
+				f32 y
+			}
+		 */
+	}
+
+	{ // Enumeration
+		Thing :: type enum {
+			APPLE,
+			FROG,
+			TREE,
+			TOMB,
+		}
+		a := Thing.APPLE
+
+		Sized :: type enum u64 {
+			APPLE,
+			FROG,
+			TREE,
+			TOMB,
+		}
+		assert(size_of(Sized) == size_of(u64))
+
+		Certain :: type enum {
+			APPLE = 3,
+			FROG,
+			TREE = 7,
+			TOMB,
+		}
+		assert(Certain.TOMB == 8)
+	}
+
+	{ // Untagged union
+		BitHack :: type raw_union {
+			i: i32
+			f: f32
+		}
+		b: BitHack
+		b.f = 123
+		print_int(b.i as int); print_nl()
+
+
+
+		// Manually tagged union
+
+		EntityKind :: type enum {
+			Invalid,
+			Constant,
+			Variable,
+			TypeName,
+			Procedure,
+			Builtin,
+			Count,
+		}
+
+		Entity :: type struct {
+			kind: EntityKind
+			guid: u64
+
+			// Other data
+
+			/*using*/
+			data: union {
+				constant: struct{}
+				variable: struct{
+					visited, is_field, used, anonymous: bool
+				}
+				procedure: struct { used: bool }
+				buitlin: struct { id: i32 }
+			}
+		}
+
+
+		// NOTE(bill): Tagged unions are not added yet but are planned
+	}
+
+
+
+	{ // Compound Literals
+		a := [3]int{1, 2, 3}
+		b := [3]int{}
+		c := [..]int{1, 2, 3}
+
+		d := []int{1, 2, 3} // slice
+
+		e := {4}f32{1, 2, 3, 4}
+		f := {4}f32{1} // broadcasts to all
+		// g := {4}f32{1, 2} // require either 1 or 4 elements
+
+		Vec2 :: type {2}f32
+
+		h := Vec2{1, 2}
+
+		i := Vec2{5} * h // For strong type safety
+		// FORENOTE: 5 * h was originally allowed but it was an edge case in the
+		// compiler I didn't think it was enough to justify have it it.
+
+		print_f32(i[0]); print_rune(#rune ",")
+		print_f32(i[1]); print_nl()
+	}
+
+
+
+	{ // First class procedures
+
+		do_thing :: proc(p: proc(a, b: int) -> int) {
+			print_int(p(3, 4)); nl()
+		}
+
+		add :: proc(a, b: int) -> int {
+			return a + b
+		}
+
+
+		add_lambda := proc(a, b: int) -> int {
+			return a - b
+		} // note semicolon
+
+		do_thing(add)
+		do_thing(add_lambda)
+		do_thing(proc(a, b: int) -> int { // Anonymous
+			return a * b
+		})
+	}
+
+
+
+	{ // strings and runes
+		escaped := "Hellope World\n"
+		raw     := `Hellope World\n`
+		print_string(escaped)
+		print_string(raw); nl()
+
+		// Crap shader example
+		shader_string :=
+`#version 410
+
+layout (location = 0) in vec3 a_position
+layout (location = 1) in vec3 a_normal;
+layout (location = 2) in vec2 a_tex_coord;
+
+out vec3 v_position;
+out vec3 v_normal;
+out vec2 v_tex_coord;
+
+uniform mat4 u_model_view;
+uniform mat3 u_normal;
+uniform mat4 u_proj;
+uniform mat4 u_mvp;
+
+void main() {
+    v_tex_coord = a_tex_coord;
+    v_normal = normalize(u_normal * a_normal);
+    v_position = vec3(u_model_view * vec4(a_position, 1.0));
+
+    gl_Position = u_mvp * vec4(a_position, 1.0);
+}`;
+
+
+		hearts1 := #rune "💕";
+		hearts2 := #rune "\U0001f495"; // 32 bit
+		hearts3 := #rune "\xf0\x9f\x92\x95";
+
+		㐒 := #rune "㐒";
+		㐒16 := #rune "\u4db5"; // 16 bit but will be `rune`
+		// String ideas "nicked" from Go, so far. I think I might change how some of it works later.
+	}
+
+
+	{ // size, align, offset
+		Thing :: type struct {
+			a: u8;
+			b: u16;
+			c, d, e: u32;
+		}
+
+		s := size_of(Thing);
+		a := align_of(Thing);
+		o := offset_of(Thing, b);
+
+		t: Thing;
+
+		sv := size_of_val(t);
+		av := align_of_val(t);
+		ov := offset_of_val(t.b);
+	}
+}
+
+data_control :: proc() {
+	sum := 0
+	for i := 0; i < 12; i++ {
+		sum += 1
+	}
+	print_string("sum = "); print_int(sum); nl()
+
+	sum = 1
+	for ; sum < 1000000; {
+		sum += sum
+	}
+	print_string("sum = "); print_int(sum); nl()
+
+	sum = 1
+	for sum < 1000000 {
+		sum += sum
+	}
+	print_string("sum = "); print_int(sum); nl()
+
+	// loop
+	// for { } == for true {}
+
+	// Question: Should I separate all these concepts and rename it?
+	//
+	// range - iterable
+	// for   - c style
+	// while
+	// loop  - while true
+
+	// Notes:
+	// conditions _must_ a boolean expression
+	// i++ and i-- are statements, not expressions
+
+
+	x := 2
+	if x < 3 {
+		print_string("x < 2\n")
+	}
+
+	// Unified initializer syntax - same as for statements
+	if x := 2; x < 3 {
+		print_string("x < 2\n")
+	}
+
+	if x := 4; x < 3 {
+		print_string("Never called\n")
+	} else {
+		print_string("This is called\n")
+	}
+
+	{ // String comparison
+		a := "Hellope"
+		b := "World"
+		if a < b {
+			print_string("a < b\n")
+		}
+		if a != b {
+			print_string("a != b\n")
+		}
+
+	}
+
+
+
+
+	{ // Defer statement
+		defer print_string("日本語\n")
+		print_string("Japanese\n")
+	}
+
+	{
+		defer print_string("1\n")
+		defer print_string("2\n")
+		defer print_string("3\n")
+	}
+
+	{
+		prev_allocator := context.allocator
+		context.allocator = __default_allocator()
+		defer context.allocator = prev_allocator
+
+		File :: type struct { filename: string }
+		FileError :: type int;
+		open_file  :: proc(filename: string) -> (File, FileError) {
+			return File{}, 0
+		}
+		close_file :: proc(f: ^File) {}
+		f, err := open_file("Test")
+		if err != 0 {
+			// handle error
+		}
+		defer close_file(^f)
+	}
+
+	for i := 0; i < 100; i++ {
+		blah := new_slice(int, 100)
+		defer {
+			defer print_string("!")
+			defer print_string("dealloc")
+			delete(blah)
+		}
+
+		if i == 3 {
+			// defers called
+			continue
+		}
+
+		if i == 5 {
+			// defers called
+			return // End of procedure
+		}
+
+		if i == 8 {
+			// defers called
+			break // never happens
+		}
+	}
+
+	defer print_string("It'll never happen, mate 1")
+	print_string("It'll never happen, mate 2")
+	print_string("It'll never happen, mate 3")
+}
+
+
+using_fields :: proc() {
+	{ // Everyday stuff
+		Vec3 :: type struct { x, y, z: f32; }
+
+		Entity :: type struct {
+			name: string;
+			using pos: Vec3;
+			vel: Vec3;
+		}
+		t: Entity;
+		t.y = 456;
+		print_f32(t.y);     print_nl();
+		print_f32(t.pos.y); print_nl();
+		print_f32(t.vel.y); print_nl();
+
+
+		Frog :: type struct { // Subtype (kind of)
+			using entity: Entity;
+			colour: u32;
+			jump_height: f32;
+		}
+
+		f: Frog;
+		f.y = 1337;
+		print_f32(f.y);     print_nl();
+		print_f32(f.pos.y); print_nl();
+		print_f32(f.vel.y); print_nl();
+
+
+		Buffalo :: type struct {
+			using entity: Entity;
+			speed: f32;
+			noise_level: f32;
+		}
+	}
+
+
+	{ // Crazy Shit
+		Vec2 :: type raw_union {
+			using _xy: struct {x, y: f32};
+			e: [2]f32;
+			v: {2}f32;
+		}
+
+		Entity :: type struct {
+			using pos: ^Vec2;
+			name: string;
+		}
+		t: Entity;
+		t.pos = alloc(size_of(Vec2)) as ^Vec2; // TODO(bill): make an alloc type? i.e. new(Type)?
+		t.x = 123;
+		print_f32(t._xy.x);     print_nl();
+		print_f32(t.pos.x);     print_nl();
+		print_f32(t.pos._xy.x); print_nl();
+	}
+}
+*/