--- /dev/null
+// vim: set ft=odin sw=4 ts=8 et:
+
+// START_INDENT
+
+#+vet !using-stmt !using-param
+#+feature dynamic-literals using-stmt
+package main
+
+import "core:fmt"
+import "core:mem"
+import "core:os"
+import "core:thread"
+import "core:time"
+import "core:reflect"
+import "base:runtime"
+import "base:intrinsics"
+import "core:math/big"
+import "core:math/rand"
+
+/*
+Odin is a general-purpose programming language with distinct typing built
+for high performance, modern systems and data-oriented programming.
+
+Odin is the C alternative for the Joy of Programming.
+
+# Installing Odin
+Getting Started - https://odin-lang.org/docs/install/
+Instructions for downloading and install the Odin compiler and libraries.
+
+# Learning Odin
+Getting Started - https://odin-lang.org/docs/install/
+Getting Started with Odin. Downloading, installing, and getting your
+first program to compile and run.
+Overview of Odin - https://odin-lang.org/docs/overview/
+An overview of the Odin programming language and its features.
+Frequently Asked Questions (FAQ) - https://odin-lang.org/docs/faq/
+Answers to common questions about Odin.
+Packages - https://pkg.odin-lang.org/
+Documentation for all the official packages part of the
+core and vendor library collections.
+Nightly Builds - https://odin-lang.org/docs/nightly/
+Get the latest nightly builds of Odin.
+More Odin Examples - https://github.com/odin-lang/examples
+This repository contains examples of how certain things can be accomplished
+in idiomatic Odin, allowing you learn its semantics, as well as how to use
+parts of the core and vendor package collections.
+*/
+
+the_basics :: proc() {
+fmt.println("\n# the basics")
+
+{ // The Basics
+
+// os.args holds the path to the current executable and any arguments passed to it.
+if len(os.args) == 1 {
+fmt.printf("Hellope from %v.\n", os.args[0])
+} else if len(os.args) > 2 {
+fmt.printf("%v, %v! from %v.\n", os.args[1], os.args[2], os.args[0])
+}
+
+// Lexical elements and literals
+// A comment
+
+my_integer_variable: int // A comment for documentaton
+
+// Multi-line comments begin with /* and end with */. Multi-line comments can
+// also be nested (unlike in C):
+/*
+You can have any text or code here and
+have it be commented.
+/*
+NOTE: comments can be nested!
+*/
+*/
+
+// String literals are enclosed in double quotes and character literals in single quotes.
+// Special characters are escaped with a backslash \
+
+some_string := "This is a string"
+_ = 'A' // unicode codepoint literal
+_ = '\n'
+_ = "C:\\Windows\\notepad.exe"
+// Raw string literals are enclosed with single back ticks
+_ = `C:\Windows\notepad.exe`
+
+// The length of a string in bytes can be found using the built-in `len` procedure:
+_ = len("Foo")
+_ = len(some_string)
+
+
+// Numbers
+
+// Numerical literals are written similar to most other programming languages.
+// A useful feature in Odin is that underscores are allowed for better
+// readability: 1_000_000_000 (one billion). A number that contains a dot is a
+// floating point literal: 1.0e9 (one billion). If a number literal is suffixed
+// with i, is an imaginary number literal: 2i (2 multiply the square root of -1).
+
+// Binary literals are prefixed with 0b, octal literals with 0o, and hexadecimal
+// literals 0x. A leading zero does not produce an octal constant (unlike C).
+
+// In Odin, if a numeric constant can be represented by a type without
+// precision loss, it will automatically convert to that type.
+
+x: int = 1.0 // A float literal but it can be represented by an integer without precision loss
+// Constant literals are “untyped” which means that they can implicitly convert to a type.
+
+y: int // `y` is typed of type `int`
+y = 1 // `1` is an untyped integer literal which can implicitly convert to `int`
+
+z: f64 // `z` is typed of type `f64` (64-bit floating point number)
+z = 1 // `1` is an untyped integer literal which can be implicitly converted to `f64`
+// No need for any suffixes or decimal places like in other languages
+// (with the exception of negative zero, which must be given as `-0.0`)
+// CONSTANTS JUST WORK!!!
+
+
+// Assignment statements
+h: int = 123 // declares a new variable `h` with type `int` and assigns a value to it
+h = 637 // assigns a new value to `h`
+
+// `=` is the assignment operator
+
+// You can assign multiple variables with it:
+a, b := 1, "hello" // declares `a` and `b` and infers the types from the assignments
+b, a = "byte", 0
+
+// Note: `:=` is two tokens, `:` and `=`. The following are equivalent,
+/*
+i: int = 123
+i: = 123
+i := 123
+*/
+
+// Constant declarations
+// Constants are entities (symbols) which have an assigned value.
+// The constant’s value cannot be changed.
+// The constant’s value must be able to be evaluated at compile time:
+X :: "what" // constant `X` has the untyped string value "what"
+
+// Constants can be explicitly typed like a variable declaration:
+Y : int : 123
+Z :: Y + 7 // constant computations are possible
+
+_ = my_integer_variable
+_ = x
+}
+}
+
+control_flow :: proc() {
+fmt.println("\n# control flow")
+{ // Control flow
+// For loop
+// Odin has only one loop statement, the `for` loop
+
+// Basic for loop
+for i := 0; i < 10; i += 1 {
+fmt.println(i)
+}
+
+// NOTE: Unlike other languages like C, there are no parentheses `( )` surrounding the three components.
+// Braces `{ }` or a `do` are always required
+for i := 0; i < 10; i += 1 { }
+// for i := 0; i < 10; i += 1 do fmt.print()
+
+// The initial and post statements are optional
+i := 0
+for ; i < 10; {
+i += 1
+}
+
+// These semicolons can be dropped. This `for` loop is equivalent to C's `while` loop
+i = 0
+for i < 10 {
+i += 1
+}
+
+// If the condition is omitted, an infinite loop is produced:
+for {
+break
+}
+
+// Range-based for loop
+// The basic for loop
+for j := 0; j < 10; j += 1 {
+fmt.println(j)
+}
+// can also be written
+for j in 0..<10 {
+fmt.println(j)
+}
+for j in 0..=9 {
+fmt.println(j)
+}
+
+// Certain built-in types can be iterated over
+some_string := "Hello, 世界"
+for character in some_string { // Strings are assumed to be UTF-8
+fmt.println(character)
+}
+
+some_array := [3]int{1, 4, 9}
+for value in some_array {
+fmt.println(value)
+}
+
+some_slice := []int{1, 4, 9}
+for value in some_slice {
+fmt.println(value)
+}
+
+some_dynamic_array := [dynamic]int{1, 4, 9}
+defer delete(some_dynamic_array)
+for value in some_dynamic_array {
+fmt.println(value)
+}
+
+
+some_map := map[string]int{"A" = 1, "C" = 9, "B" = 4}
+defer delete(some_map)
+for key in some_map {
+fmt.println(key)
+}
+
+// Alternatively a second index value can be added
+for character, index in some_string {
+fmt.println(index, character)
+}
+for value, index in some_array {
+fmt.println(index, value)
+}
+for value, index in some_slice {
+fmt.println(index, value)
+}
+for value, index in some_dynamic_array {
+fmt.println(index, value)
+}
+for key, value in some_map {
+fmt.println(key, value)
+}
+
+// The iterated values are copies and cannot be written to.
+// The following idiom is useful for iterating over a container in a by-reference manner:
+for _, idx in some_slice {
+some_slice[idx] = (idx+1)*(idx+1)
+}
+
+
+// If statements
+x := 123
+if x >= 0 {
+fmt.println("x is positive")
+}
+
+if y := -34; y < 0 {
+fmt.println("y is negative")
+}
+
+if y := 123; y < 0 {
+fmt.println("y is negative")
+} else if y == 0 {
+fmt.println("y is zero")
+} else {
+fmt.println("y is positive")
+}
+
+// Switch statement
+// A switch statement is another way to write a sequence of if-else statements.
+// In Odin, the default case is denoted as a case without any expression.
+
+#partial switch arch := ODIN_ARCH; arch {
+case .i386:
+fmt.println("32-bit")
+case .amd64:
+fmt.println("64-bit")
+case: // default
+fmt.println("Unsupported architecture")
+}
+
+// Odin’s `switch` is like one in C or C++, except that Odin only runs the selected case.
+// This means that a `break` statement is not needed at the end of each case.
+// Another important difference is that the case values need not be integers nor constants.
+
+// To achieve a C-like fall through into the next case block, the keyword `fallthrough` can be used.
+one_angry_dwarf :: proc() -> int {
+fmt.println("one_angry_dwarf was called")
+return 1
+}
+
+switch j := 0; j {
+case 0:
+case one_angry_dwarf():
+}
+
+// A switch statement without a condition is the same as `switch true`.
+// This can be used to write a clean and long if-else chain and have the
+// ability to break if needed
+
+switch {
+case x < 0:
+fmt.println("x is negative")
+case x == 0:
+fmt.println("x is zero")
+case:
+fmt.println("x is positive")
+}
+
+// A `switch` statement can also use ranges like a range-based loop:
+switch c := 'j'; c {
+case 'A'..='Z', 'a'..='z', '0'..='9':
+fmt.println("c is alphanumeric")
+}
+
+switch x {
+case 0..<10:
+fmt.println("units")
+case 10..<13:
+fmt.println("pre-teens")
+case 13..<20:
+fmt.println("teens")
+case 20..<30:
+fmt.println("twenties")
+}
+}
+
+{ // Defer statement
+// A defer statement defers the execution of a statement until the end of
+// the scope it is in.
+
+// The following will print 4 then 234:
+{
+x := 123
+defer fmt.println(x)
+{
+defer x = 4
+x = 2
+}
+fmt.println(x)
+
+x = 234
+}
+
+// You can defer an entire block too:
+{
+bar :: proc() {}
+
+defer {
+fmt.println("1")
+fmt.println("2")
+}
+
+cond := false
+defer if cond {
+bar()
+}
+}
+
+// Defer statements are executed in the reverse order that they were declared:
+{
+defer fmt.println("1")
+defer fmt.println("2")
+defer fmt.println("3")
+}
+// Will print 3, 2, and then 1.
+
+if false {
+f, err := os.open("my_file.txt")
+if err != nil {
+// handle error
+}
+defer os.close(f)
+// rest of code
+}
+}
+
+{ // When statement
+/*
+The when statement is almost identical to the if statement but with some differences:
+
+* Each condition must be a constant expression as a when
+statement is evaluated at compile time.
+* The statements within a branch do not create a new scope
+* The compiler checks the semantics and code only for statements
+that belong to the first condition that is true
+* An initial statement is not allowed in a when statement
+* when statements are allowed at file scope
+*/
+
+// Example
+when ODIN_ARCH == .i386 {
+fmt.println("32 bit")
+} else when ODIN_ARCH == .amd64 {
+fmt.println("64 bit")
+} else {
+fmt.println("Unknown architecture")
+}
+// The when statement is very useful for writing platform specific code.
+// This is akin to the #if construct in C’s preprocessor however, in Odin,
+// it is type checked.
+}
+
+{ // Branch statements
+cond, cond1, cond2 := false, false, false
+one_step :: proc() { fmt.println("one_step") }
+beyond :: proc() { fmt.println("beyond") }
+
+// Break statement
+for cond {
+switch {
+case:
+if cond {
+break // break out of the `switch` statement
+}
+}
+
+break // break out of the `for` statement
+}
+
+loop: for cond1 {
+for cond2 {
+break loop // leaves both loops
+}
+}
+
+// Continue statement
+for cond {
+if cond2 {
+continue
+}
+fmt.println("Hellope")
+}
+
+// Fallthrough statement
+
+// Odin’s switch is like one in C or C++, except that Odin only runs the selected
+// case. This means that a break statement is not needed at the end of each case.
+// Another important difference is that the case values need not be integers nor
+// constants.
+
+// fallthrough can be used to explicitly fall through into the next case block:
+
+switch i := 0; i {
+case 0:
+one_step()
+fallthrough
+case 1:
+beyond()
+}
+}
+}
+
+
+named_proc_return_parameters :: proc() {
+fmt.println("\n# named proc return parameters")
+
+foo0 :: proc() -> int {
+return 123
+}
+foo1 :: proc() -> (a: int) {
+a = 123
+return
+}
+foo2 :: proc() -> (a, b: int) {
+// Named return values act like variables within the scope
+a = 321
+b = 567
+return b, a
+}
+fmt.println("foo0 =", foo0()) // 123
+fmt.println("foo1 =", foo1()) // 123
+fmt.println("foo2 =", foo2()) // 567 321
+}
+
+variadic_procedures :: proc() {
+fmt.println("\n# variadic procedures")
+sum :: proc(nums: ..int, init_value:= 0) -> (result: int) {
+result = init_value
+for n in nums {
+result += n
+}
+return
+}
+fmt.println("sum(()) =", sum())
+fmt.println("sum(1, 2) =", sum(1, 2))
+fmt.println("sum(1, 2, 3, 4, 5) =", sum(1, 2, 3, 4, 5))
+fmt.println("sum(1, 2, 3, 4, 5, init_value = 5) =", sum(1, 2, 3, 4, 5, init_value = 5))
+
+// pass a slice as varargs
+odds := []int{1, 3, 5}
+fmt.println("odds =", odds)
+fmt.println("sum(..odds) =", sum(..odds))
+fmt.println("sum(..odds, init_value = 5) =", sum(..odds, init_value = 5))
+}
+
+
+explicit_procedure_overloading :: proc() {
+fmt.println("\n# explicit procedure overloading")
+
+add_ints :: proc(a, b: int) -> int {
+x := a + b
+fmt.println("add_ints", x)
+return x
+}
+add_floats :: proc(a, b: f32) -> f32 {
+x := a + b
+fmt.println("add_floats", x)
+return x
+}
+add_numbers :: proc(a: int, b: f32, c: u8) -> int {
+x := int(a) + int(b) + int(c)
+fmt.println("add_numbers", x)
+return x
+}
+
+add :: proc{add_ints, add_floats, add_numbers}
+
+add(int(1), int(2))
+add(f32(1), f32(2))
+add(int(1), f32(2), u8(3))
+
+add(1, 2) // untyped ints coerce to int tighter than f32
+add(1.0, 2.0) // untyped floats coerce to f32 tighter than int
+add(1, 2, 3) // three parameters
+
+// Ambiguous answers
+// add(1.0, 2)
+// add(1, 2.0)
+}
+
+struct_type :: proc() {
+fmt.println("\n# struct type")
+// A struct is a record type in Odin. It is a collection of fields.
+// Struct fields are accessed by using a dot:
+{
+Vector2 :: struct {
+x: f32,
+y: f32,
+}
+v := Vector2{1, 2}
+v.x = 4
+fmt.println(v.x)
+
+// Struct fields can be accessed through a struct pointer:
+
+v = Vector2{1, 2}
+p := &v
+p.x = 1335
+fmt.println(v)
+
+// We could write p^.x, however, it is nice to abstract the ability
+// to not explicitly dereference the pointer. This is very useful when
+// refactoring code to use a pointer rather than a value, and vice versa.
+}
+{
+// A struct literal can be denoted by providing the struct’s type
+// followed by {}. A struct literal must either provide all the
+// arguments or none:
+Vector3 :: struct {
+x, y, z: f32,
+}
+v: Vector3
+v = Vector3{} // Zero value
+v = Vector3{1, 4, 9}
+
+// You can list just a subset of the fields if you specify the
+// field by name (the order of the named fields does not matter):
+v = Vector3{z=1, y=2}
+assert(v.x == 0)
+assert(v.y == 2)
+assert(v.z == 1)
+}
+{
+// Structs can tagged with different memory layout and alignment requirements:
+
+a :: struct #align(4) {} // align to 4 bytes
+b :: struct #packed {} // remove padding between fields
+c :: struct #raw_union {} // all fields share the same offset (0). This is the same as C's union
+}
+
+}
+
+
+union_type :: proc() {
+fmt.println("\n# union type")
+{
+val: union{int, bool}
+val = 137
+if i, ok := val.(int); ok {
+fmt.println(i)
+}
+val = true
+fmt.println(val)
+
+val = nil
+
+switch v in val {
+case int: fmt.println("int", v)
+case bool: fmt.println("bool", v)
+case: fmt.println("nil")
+}
+}
+{
+// There is a duality between `any` and `union`
+// An `any` has a pointer to the data and allows for any type (open)
+// A `union` has as binary blob to store the data and allows only certain types (closed)
+// The following code is with `any` but has the same syntax
+val: any
+val = 137
+if i, ok := val.(int); ok {
+fmt.println(i)
+}
+val = true
+fmt.println(val)
+
+val = nil
+
+switch v in val {
+case int: fmt.println("int", v)
+case bool: fmt.println("bool", v)
+case: fmt.println("nil")
+}
+}
+
+Vector3 :: distinct [3]f32
+Quaternion :: distinct quaternion128
+
+// More realistic examples
+{
+// NOTE(bill): For the above basic examples, you may not have any
+// particular use for it. However, my main use for them is not for these
+// simple cases. My main use is for hierarchical types. Many prefer
+// subtyping, embedding the base data into the derived types. Below is
+// an example of this for a basic game Entity.
+
+Entity :: struct {
+id: u64,
+name: string,
+position: Vector3,
+orientation: Quaternion,
+
+derived: any,
+}
+
+Frog :: struct {
+using entity: Entity,
+jump_height: f32,
+}
+
+Monster :: struct {
+using entity: Entity,
+is_robot: bool,
+is_zombie: bool,
+}
+
+// See `parametric_polymorphism` procedure for details
+new_entity :: proc($T: typeid) -> ^Entity {
+t := new(T)
+t.derived = t^
+return t
+}
+
+entity := new_entity(Monster)
+
+switch e in entity.derived {
+case Frog:
+fmt.println("Ribbit")
+case Monster:
+if e.is_robot { fmt.println("Robotic") }
+if e.is_zombie { fmt.println("Grrrr!") }
+fmt.println("I'm a monster")
+}
+}
+
+{
+// NOTE(bill): A union can be used to achieve something similar. Instead
+// of embedding the base data into the derived types, the derived data
+// in embedded into the base type. Below is the same example of the
+// basic game Entity but using an union.
+
+Entity :: struct {
+id: u64,
+name: string,
+position: Vector3,
+orientation: Quaternion,
+
+derived: union {Frog, Monster},
+}
+
+Frog :: struct {
+using entity: ^Entity,
+jump_height: f32,
+}
+
+Monster :: struct {
+using entity: ^Entity,
+is_robot: bool,
+is_zombie: bool,
+}
+
+// See `parametric_polymorphism` procedure for details
+new_entity :: proc($T: typeid) -> ^Entity {
+t := new(Entity)
+t.derived = T{entity = t}
+return t
+}
+
+entity := new_entity(Monster)
+
+switch e in entity.derived {
+case Frog:
+fmt.println("Ribbit")
+case Monster:
+if e.is_robot { fmt.println("Robotic") }
+if e.is_zombie { fmt.println("Grrrr!") }
+}
+
+// NOTE(bill): As you can see, the usage code has not changed, only its
+// memory layout. Both approaches have their own advantages but they can
+// be used together to achieve different results. The subtyping approach
+// can allow for a greater control of the memory layout and memory
+// allocation, e.g. storing the derivatives together. However, this is
+// also its disadvantage. You must either preallocate arrays for each
+// derivative separation (which can be easily missed) or preallocate a
+// bunch of "raw" memory; determining the maximum size of the derived
+// types would require the aid of metaprogramming. Unions solve this
+// particular problem as the data is stored with the base data.
+// Therefore, it is possible to preallocate, e.g. [100]Entity.
+
+// It should be noted that the union approach can have the same memory
+// layout as the any and with the same type restrictions by using a
+// pointer type for the derivatives.
+
+/*
+Entity :: struct {
+...
+derived: union{^Frog, ^Monster},
+}
+
+Frog :: struct {
+using entity: Entity,
+...
+}
+Monster :: struct {
+using entity: Entity,
+...
+
+}
+new_entity :: proc(T: type) -> ^Entity {
+t := new(T)
+t.derived = t
+return t
+}
+*/
+}
+}
+
+using_statement :: proc() {
+// IMPORTANT NOTE: `using` as a statement is an opt-in feature which can be abled
+// by adding `#+feature using-stmt` to be beginning of the file
+//
+// `using` as a struct field modifier remains available always
+
+fmt.println("\n# using statement")
+// using can used to bring entities declared in a scope/namespace
+// into the current scope. This can be applied to import names, struct
+// fields, procedure fields, and struct values.
+
+Vector3 :: struct{x, y, z: f32}
+{
+Entity :: struct {
+position: Vector3,
+orientation: quaternion128,
+}
+
+// It can used like this:
+foo0 :: proc(entity: ^Entity) {
+fmt.println(entity.position.x, entity.position.y, entity.position.z)
+}
+
+// The entity members can be brought into the procedure scope by using it:
+foo1 :: proc(entity: ^Entity) {
+using entity
+fmt.println(position.x, position.y, position.z)
+}
+
+// The using can be applied to the parameter directly:
+foo2 :: proc(using entity: ^Entity) {
+fmt.println(position.x, position.y, position.z)
+}
+
+// It can also be applied to sub-fields:
+foo3 :: proc(entity: ^Entity) {
+using entity.position
+fmt.println(x, y, z)
+}
+}
+{
+// We can also apply the using statement to the struct fields directly,
+// making all the fields of position appear as if they on Entity itself:
+Entity :: struct {
+using position: Vector3,
+orientation: quaternion128,
+}
+foo :: proc(entity: ^Entity) {
+fmt.println(entity.x, entity.y, entity.z)
+}
+
+
+// Subtype polymorphism
+// It is possible to get subtype polymorphism, similar to inheritance-like
+// functionality in C++, but without the requirement of vtables or unknown
+// struct layout:
+
+Colour :: struct {r, g, b, a: u8}
+Frog :: struct {
+ribbit_volume: f32,
+using entity: Entity,
+colour: Colour,
+}
+
+frog: Frog
+// Both work
+foo(&frog.entity)
+foo(&frog)
+frog.x = 123
+
+// Note: using can be applied to arbitrarily many things, which allows
+// the ability to have multiple subtype polymorphism (but also its issues).
+
+// Note: using’d fields can still be referred by name.
+}
+}
+
+
+implicit_context_system :: proc() {
+fmt.println("\n# implicit context system")
+// In each scope, there is an implicit value named context. This
+// context variable is local to each scope and is implicitly passed
+// by pointer to any procedure call in that scope (if the procedure
+// has the Odin calling convention).
+
+// The main purpose of the implicit context system is for the ability
+// to intercept third-party code and libraries and modify their
+// functionality. One such case is modifying how a library allocates
+// something or logs something. In C, this was usually achieved with
+// the library defining macros which could be overridden so that the
+// user could define what he wanted. However, not many libraries
+// supported this in many languages by default which meant intercepting
+// third-party code to see what it does and to change how it does it is
+// not possible.
+
+c := context // copy the current scope's context
+
+context.user_index = 456
+{
+context.allocator = my_custom_allocator()
+context.user_index = 123
+what_a_fool_believes() // the `context` for this scope is implicitly passed to `what_a_fool_believes`
+}
+
+// `context` value is local to the scope it is in
+assert(context.user_index == 456)
+
+what_a_fool_believes :: proc() {
+c := context // this `context` is the same as the parent procedure that it was called from
+// From this example, context.user_index == 123
+// A context.allocator is assigned to the return value of `my_custom_allocator()`
+assert(context.user_index == 123)
+
+// The memory management procedure use the `context.allocator` by
+// default unless explicitly specified otherwise
+china_grove := new(int)
+free(china_grove)
+
+_ = c
+}
+
+my_custom_allocator :: mem.nil_allocator
+_ = c
+
+// By default, the context value has default values for its parameters which is
+// decided in the package runtime. What the defaults are are compiler specific.
+
+// To see what the implicit context value contains, please see the following
+// definition in package runtime.
+}
+
+parametric_polymorphism :: proc() {
+fmt.println("\n# parametric polymorphism")
+
+print_value :: proc(value: $T) {
+fmt.printf("print_value: %T %v\n", value, value)
+}
+
+v1: int = 1
+v2: f32 = 2.1
+v3: f64 = 3.14
+v4: string = "message"
+
+print_value(v1)
+print_value(v2)
+print_value(v3)
+print_value(v4)
+
+fmt.println()
+
+add :: proc(p, q: $T) -> T {
+x: T = p + q
+return x
+}
+
+a := add(3, 4)
+fmt.printf("a: %T = %v\n", a, a)
+
+b := add(3.2, 4.3)
+fmt.printf("b: %T = %v\n", b, b)
+
+// This is how `new` is implemented
+alloc_type :: proc($T: typeid) -> ^T {
+t := cast(^T)mem.alloc(size_of(T), align_of(T))
+t^ = T{} // Use default initialization value
+return t
+}
+
+copy_slice :: proc(dst, src: []$T) -> int {
+n := min(len(dst), len(src))
+if n > 0 {
+mem.copy(&dst[0], &src[0], n*size_of(T))
+}
+return n
+}
+
+double_params :: proc(a: $A, b: $B) -> A {
+return a + A(b)
+}
+
+fmt.println(double_params(12, 1.345))
+
+
+
+{ // Polymorphic Types and Type Specialization
+Table_Slot :: struct($Key, $Value: typeid) {
+occupied: bool,
+hash: u32,
+key: Key,
+value: Value,
+}
+TABLE_SIZE_MIN :: 32
+Table :: struct($Key, $Value: typeid) {
+count: int,
+allocator: mem.Allocator,
+slots: []Table_Slot(Key, Value),
+}
+
+// Only allow types that are specializations of a (polymorphic) slice
+make_slice :: proc($T: typeid/[]$E, len: int) -> T {
+return make(T, len)
+}
+
+// Only allow types that are specializations of `Table`
+allocate :: proc(table: ^$T/Table, capacity: int) {
+c := context
+if table.allocator.procedure != nil {
+c.allocator = table.allocator
+}
+context = c
+
+table.slots = make_slice(type_of(table.slots), max(capacity, TABLE_SIZE_MIN))
+}
+
+expand :: proc(table: ^$T/Table) {
+c := context
+if table.allocator.procedure != nil {
+c.allocator = table.allocator
+}
+context = c
+
+old_slots := table.slots
+defer delete(old_slots)
+
+cap := max(2*len(table.slots), TABLE_SIZE_MIN)
+allocate(table, cap)
+
+for s in old_slots {
+if s.occupied {
+put(table, s.key, s.value)
+}
+}
+}
+
+// Polymorphic determination of a polymorphic struct
+// put :: proc(table: ^$T/Table, key: T.Key, value: T.Value) {
+put :: proc(table: ^Table($Key, $Value), key: Key, value: Value) {
+hash := get_hash(key) // Ad-hoc method which would fail in a different scope
+index := find_index(table, key, hash)
+if index < 0 {
+if f64(table.count) >= 0.75*f64(len(table.slots)) {
+expand(table)
+}
+assert(table.count <= len(table.slots))
+
+index = int(hash % u32(len(table.slots)))
+
+for table.slots[index].occupied {
+if index += 1; index >= len(table.slots) {
+index = 0
+}
+}
+
+table.count += 1
+}
+
+slot := &table.slots[index]
+slot.occupied = true
+slot.hash = hash
+slot.key = key
+slot.value = value
+}
+
+
+// find :: proc(table: ^$T/Table, key: T.Key) -> (T.Value, bool) {
+find :: proc(table: ^Table($Key, $Value), key: Key) -> (Value, bool) {
+hash := get_hash(key)
+index := find_index(table, key, hash)
+if index < 0 {
+return Value{}, false
+}
+return table.slots[index].value, true
+}
+
+find_index :: proc(table: ^Table($Key, $Value), key: Key, hash: u32) -> int {
+if len(table.slots) <= 0 {
+return -1
+}
+
+index := int(hash % u32(len(table.slots)))
+for table.slots[index].occupied {
+if table.slots[index].hash == hash {
+if table.slots[index].key == key {
+return index
+}
+}
+
+if index += 1; index >= len(table.slots) {
+index = 0
+}
+}
+
+return -1
+}
+
+get_hash :: proc(s: string) -> u32 { // fnv32a
+h: u32 = 0x811c9dc5
+for i in 0..<len(s) {
+h = (h ~ u32(s[i])) * 0x01000193
+}
+return h
+}
+
+
+table: Table(string, int)
+
+for i in 0..=36 { put(&table, "Hellope", i) }
+for i in 0..=42 { put(&table, "World!", i) }
+
+found, _ := find(&table, "Hellope")
+fmt.printf("`found` is %v\n", found)
+
+found, _ = find(&table, "World!")
+fmt.printf("`found` is %v\n", found)
+
+// I would not personally design a hash table like this in production
+// but this is a nice basic example
+// A better approach would either use a `u64` or equivalent for the key
+// and let the user specify the hashing function or make the user store
+// the hashing procedure with the table
+}
+
+{ // Parametric polymorphic union
+Error :: enum {
+Foo0,
+Foo1,
+Foo2,
+Foo3,
+}
+Para_Union :: union($T: typeid) {T, Error}
+r: Para_Union(int)
+fmt.println(typeid_of(type_of(r)))
+
+fmt.println(r)
+r = 123
+fmt.println(r)
+r = Error.Foo0 // r = .Foo0 is allow too, see implicit selector expressions below
+fmt.println(r)
+}
+
+{ // Polymorphic names
+foo :: proc($N: $I, $T: typeid) -> (res: [N]T) {
+// `N` is the constant value passed
+// `I` is the type of N
+// `T` is the type passed
+fmt.printf("Generating an array of type %v from the value %v of type %v\n",
+typeid_of(type_of(res)), N, typeid_of(I))
+for i in 0..<N {
+res[i] = T(i*i)
+}
+return
+}
+
+T :: int
+array := foo(4, T)
+for v, i in array {
+assert(v == T(i*i))
+}
+
+// Matrix multiplication
+mul :: proc(a: [$M][$N]$T, b: [N][$P]T) -> (c: [M][P]T) {
+for i in 0..<M {
+for j in 0..<P {
+for k in 0..<N {
+c[i][j] += a[i][k] * b[k][j]
+}
+}
+}
+return
+}
+
+x := [2][3]f32{
+{1, 2, 3},
+{3, 2, 1},
+}
+y := [3][2]f32{
+{0, 8},
+{6, 2},
+{8, 4},
+}
+z := mul(x, y)
+assert(z == {{36, 24}, {20, 32}})
+}
+}
+
+
+prefix_table := [?]string{
+"White",
+"Red",
+"Green",
+"Blue",
+"Octarine",
+"Black",
+}
+
+print_mutex := b64(false)
+
+@(disabled=!thread.IS_SUPPORTED)
+threading_example :: proc() {
+fmt.println("\n# threading_example")
+
+did_acquire :: proc(m: ^b64) -> (acquired: bool) {
+res, ok := intrinsics.atomic_compare_exchange_strong(m, false, true)
+return ok && res == false
+}
+
+{ // Basic Threads
+fmt.println("\n## Basic Threads")
+worker_proc :: proc(t: ^thread.Thread) {
+for iteration in 1..=5 {
+fmt.printf("Thread %d is on iteration %d\n", t.user_index, iteration)
+fmt.printf("`%s`: iteration %d\n", prefix_table[t.user_index], iteration)
+time.sleep(1 * time.Millisecond)
+}
+}
+
+threads := make([dynamic]^thread.Thread, 0, len(prefix_table))
+defer delete(threads)
+
+for _ in prefix_table {
+if t := thread.create(worker_proc); t != nil {
+t.init_context = context
+t.user_index = len(threads)
+append(&threads, t)
+thread.start(t)
+}
+}
+
+for len(threads) > 0 {
+for i := 0; i < len(threads); /**/ {
+if t := threads[i]; thread.is_done(t) {
+fmt.printf("Thread %d is done\n", t.user_index)
+thread.destroy(t)
+
+ordered_remove(&threads, i)
+} else {
+i += 1
+}
+}
+}
+}
+
+{ // Thread Pool
+fmt.println("\n## Thread Pool")
+task_proc :: proc(t: thread.Task) {
+index := t.user_index % len(prefix_table)
+for iteration in 1..=5 {
+for !did_acquire(&print_mutex) { thread.yield() } // Allow one thread to print at a time.
+
+fmt.printf("Worker Task %d is on iteration %d\n", t.user_index, iteration)
+fmt.printf("`%s`: iteration %d\n", prefix_table[index], iteration)
+
+print_mutex = false
+
+time.sleep(1 * time.Millisecond)
+}
+}
+
+N :: 3
+
+pool: thread.Pool
+thread.pool_init(&pool, allocator=context.allocator, thread_count=N)
+defer thread.pool_destroy(&pool)
+
+
+for i in 0..<30 {
+// be mindful of the allocator used for tasks. The allocator needs to be thread safe, or be owned by the task for exclusive use
+thread.pool_add_task(&pool, allocator=context.allocator, procedure=task_proc, data=nil, user_index=i)
+}
+
+thread.pool_start(&pool)
+thread.pool_finish(&pool)
+}
+}
+
+
+array_programming :: proc() {
+fmt.println("\n# array programming")
+{
+a := [3]f32{1, 2, 3}
+b := [3]f32{5, 6, 7}
+c := a * b
+d := a + b
+e := 1 + (c - d) / 2
+fmt.printf("%.1f\n", e) // [0.5, 3.0, 6.5]
+}
+
+{
+a := [3]f32{1, 2, 3}
+b := swizzle(a, 2, 1, 0)
+assert(b == [3]f32{3, 2, 1})
+
+c := swizzle(a, 0, 0)
+assert(c == [2]f32{1, 1})
+assert(c == 1)
+}
+
+{
+Vector3 :: distinct [3]f32
+a := Vector3{1, 2, 3}
+b := Vector3{5, 6, 7}
+c := (a * b)/2 + 1
+d := c.x + c.y + c.z
+fmt.printf("%.1f\n", d) // 22.0
+
+cross :: proc(a, b: Vector3) -> Vector3 {
+i := swizzle(a, 1, 2, 0) * swizzle(b, 2, 0, 1)
+j := swizzle(a, 2, 0, 1) * swizzle(b, 1, 2, 0)
+return i - j
+}
+
+cross_shorter :: proc(a, b: Vector3) -> Vector3 {
+i := a.yzx * b.zxy
+j := a.zxy * b.yzx
+return i - j
+}
+
+blah :: proc(a: Vector3) -> f32 {
+return a.x + a.y + a.z
+}
+
+x := cross(a, b)
+fmt.println(x)
+fmt.println(blah(x))
+}
+}
+
+map_type :: proc() {
+fmt.println("\n# map type")
+
+m := make(map[string]int)
+defer delete(m)
+
+m["Bob"] = 2
+m["Ted"] = 5
+fmt.println(m["Bob"])
+
+delete_key(&m, "Ted")
+
+// If an element of a key does not exist, the zero value of the
+// element will be returned. To check to see if an element exists
+// can be done in two ways:
+elem, ok := m["Bob"]
+exists := "Bob" in m
+_, _ = elem, ok
+_ = exists
+}
+
+implicit_selector_expression :: proc() {
+fmt.println("\n# implicit selector expression")
+
+Foo :: enum {A, B, C}
+
+f: Foo
+f = Foo.A
+f = .A
+
+BAR :: bit_set[Foo]{.B, .C}
+
+switch f {
+case .A:
+fmt.println("HITHER")
+case .B:
+fmt.println("NEVER")
+case .C:
+fmt.println("FOREVER")
+}
+
+my_map := make(map[Foo]int)
+defer delete(my_map)
+
+my_map[.A] = 123
+my_map[Foo.B] = 345
+
+fmt.println(my_map[.A] + my_map[Foo.B] + my_map[.C])
+}
+
+
+partial_switch :: proc() {
+fmt.println("\n# partial_switch")
+{ // enum
+Foo :: enum {
+A,
+B,
+C,
+D,
+}
+
+f := Foo.A
+switch f {
+case .A: fmt.println("A")
+case .B: fmt.println("B")
+case .C: fmt.println("C")
+case .D: fmt.println("D")
+case: fmt.println("?")
+}
+
+#partial switch f {
+case .A: fmt.println("A")
+case .D: fmt.println("D")
+}
+}
+{ // union
+Foo :: union {int, bool}
+f: Foo = 123
+switch _ in f {
+case int: fmt.println("int")
+case bool: fmt.println("bool")
+case:
+}
+
+#partial switch _ in f {
+case bool: fmt.println("bool")
+}
+}
+}
+
+cstring_example :: proc() {
+fmt.println("\n# cstring_example")
+
+W :: "Hellope"
+X :: cstring(W)
+Y :: string(X)
+
+w := W
+_ = w
+x: cstring = X
+y: string = Y
+z := string(x)
+fmt.println(x, y, z)
+fmt.println(len(x), len(y), len(z))
+fmt.println(len(W), len(X), len(Y))
+// IMPORTANT NOTE for cstring variables
+// len(cstring) is O(N)
+// cast(string)cstring is O(N)
+}
+
+bit_set_type :: proc() {
+fmt.println("\n# bit_set type")
+
+{
+Day :: enum {
+Sunday,
+Monday,
+Tuesday,
+Wednesday,
+Thursday,
+Friday,
+Saturday,
+}
+
+Days :: distinct bit_set[Day]
+WEEKEND :: Days{.Sunday, .Saturday}
+
+d: Days
+d = {.Sunday, .Monday}
+e := d + WEEKEND
+e += {.Monday}
+fmt.println(d, e)
+
+ok := .Saturday in e // `in` is only allowed for `map` and `bit_set` types
+fmt.println(ok)
+if .Saturday in e {
+fmt.println("Saturday in", e)
+}
+X :: .Saturday in WEEKEND // Constant evaluation
+fmt.println(X)
+fmt.println("Cardinality:", card(e))
+}
+{
+x: bit_set['A'..='Z']
+#assert(size_of(x) == size_of(u32))
+y: bit_set[0..=8; u16]
+fmt.println(typeid_of(type_of(x))) // bit_set[A..=Z]
+fmt.println(typeid_of(type_of(y))) // bit_set[0..=8; u16]
+
+x += {'F'}
+assert('F' in x)
+x -= {'F'}
+assert('F' not_in x)
+
+y += {1, 4, 2}
+assert(2 in y)
+}
+{
+Letters :: bit_set['A'..='Z']
+a := Letters{'A', 'B'}
+b := Letters{'A', 'B', 'C', 'D', 'F'}
+c := Letters{'A', 'B'}
+
+assert(a <= b) // 'a' is a subset of 'b'
+assert(b >= a) // 'b' is a superset of 'a'
+assert(a < b) // 'a' is a strict subset of 'b'
+assert(b > a) // 'b' is a strict superset of 'a'
+
+assert(!(a < c)) // 'a' is a not strict subset of 'c'
+assert(!(c > a)) // 'c' is a not strict superset of 'a'
+}
+}
+
+deferred_procedure_associations :: proc() {
+fmt.println("\n# deferred procedure associations")
+
+@(deferred_out=closure)
+open :: proc(s: string) -> bool {
+fmt.println(s)
+return true
+}
+
+closure :: proc(ok: bool) {
+fmt.println("Goodbye?", ok)
+}
+
+if open("Welcome") {
+fmt.println("Something in the middle, mate.")
+}
+}
+
+reflection :: proc() {
+fmt.println("\n# reflection")
+
+Foo :: struct {
+x: int `tag1`,
+y: string `json:"y_field"`,
+z: bool, // no tag
+}
+
+id := typeid_of(Foo)
+names := reflect.struct_field_names(id)
+types := reflect.struct_field_types(id)
+tags := reflect.struct_field_tags(id)
+
+assert(len(names) == len(types) && len(names) == len(tags))
+
+fmt.println("Foo :: struct {")
+for tag, i in tags {
+name, type := names[i], types[i]
+if tag != "" {
+fmt.printf("\t%s: %T `%s`,\n", name, type, tag)
+} else {
+fmt.printf("\t%s: %T,\n", name, type)
+}
+}
+fmt.println("}")
+
+
+for tag, i in tags {
+if val, ok := reflect.struct_tag_lookup(tag, "json"); ok {
+fmt.printf("json: %s -> %s\n", names[i], val)
+}
+}
+}
+
+quaternions :: proc() {
+// Not just an April Fool's Joke any more, but a fully working thing!
+fmt.println("\n# quaternions")
+
+{ // Quaternion operations
+q := 1 + 2i + 3j + 4k
+r := quaternion(real=5, imag=6, jmag=7, kmag=8)
+t := q * r
+fmt.printf("(%v) * (%v) = %v\n", q, r, t)
+v := q / r
+fmt.printf("(%v) / (%v) = %v\n", q, r, v)
+u := q + r
+fmt.printf("(%v) + (%v) = %v\n", q, r, u)
+s := q - r
+fmt.printf("(%v) - (%v) = %v\n", q, r, s)
+}
+{ // The quaternion types
+q128: quaternion128 // 4xf32
+q256: quaternion256 // 4xf64
+q128 = quaternion(w=1, x=0, y=0, z=0)
+q256 = 1 // quaternion(x=0, y=0, z=0, w=1)
+
+// NOTE: The internal memory layout of a quaternion is xyzw
+}
+{ // Built-in procedures
+q := 1 + 2i + 3j + 4k
+fmt.println("q =", q)
+fmt.println("real(q) =", real(q))
+fmt.println("imag(q) =", imag(q))
+fmt.println("jmag(q) =", jmag(q))
+fmt.println("kmag(q) =", kmag(q))
+fmt.println("conj(q) =", conj(q))
+fmt.println("abs(q) =", abs(q))
+}
+{ // Conversion of a complex type to a quaternion type
+c := 1 + 2i
+q := quaternion256(c)
+fmt.println(c)
+fmt.println(q)
+}
+{ // Memory layout of Quaternions
+q := 1 + 2i + 3j + 4k
+a := transmute([4]f64)q
+fmt.println("Quaternion memory layout: xyzw/(ijkr)")
+fmt.println(q) // 1.000+2.000i+3.000j+4.000k
+fmt.println(a) // [2.000, 3.000, 4.000, 1.000]
+}
+}
+
+unroll_for_statement :: proc() {
+fmt.println("\n#'#unroll for' statements")
+
+// '#unroll for' works the same as if the 'inline' prefix did not
+// exist but these ranged loops are explicitly unrolled which can
+// be very very useful for certain optimizations
+
+fmt.println("Ranges")
+#unroll for x, i in 1..<4 {
+fmt.println(x, i)
+}
+
+fmt.println("Strings")
+#unroll for r, i in "Hello, 世界" {
+fmt.println(r, i)
+}
+
+fmt.println("Arrays")
+#unroll for elem, idx in ([4]int{1, 4, 9, 16}) {
+fmt.println(elem, idx)
+}
+
+
+Foo_Enum :: enum {
+A = 1,
+B,
+C = 6,
+D,
+}
+fmt.println("Enum types")
+#unroll for elem, idx in Foo_Enum {
+fmt.println(elem, idx)
+}
+}
+
+where_clauses :: proc() {
+fmt.println("\n#procedure 'where' clauses")
+
+{ // Sanity checks
+simple_sanity_check :: proc(x: [2]int)
+where len(x) > 1,
+type_of(x) == [2]int {
+fmt.println(x)
+}
+}
+{ // Parametric polymorphism checks
+cross_2d :: proc(a, b: $T/[2]$E) -> E
+where intrinsics.type_is_numeric(E) {
+return a.x*b.y - a.y*b.x
+}
+cross_3d :: proc(a, b: $T/[3]$E) -> T
+where intrinsics.type_is_numeric(E) {
+x := a.y*b.z - a.z*b.y
+y := a.z*b.x - a.x*b.z
+z := a.x*b.y - a.y*b.x
+return T{x, y, z}
+}
+
+a := [2]int{1, 2}
+b := [2]int{5, -3}
+fmt.println(cross_2d(a, b))
+
+x := [3]f32{1, 4, 9}
+y := [3]f32{-5, 0, 3}
+fmt.println(cross_3d(x, y))
+
+// Failure case
+// i := [2]bool{true, false}
+// j := [2]bool{false, true}
+// fmt.println(cross_2d(i, j))
+
+}
+
+{ // Procedure groups usage
+foo :: proc(x: [$N]int) -> bool
+where N > 2 {
+fmt.println(#procedure, "was called with the parameter", x)
+return true
+}
+
+bar :: proc(x: [$N]int) -> bool
+where 0 < N,
+N <= 2 {
+fmt.println(#procedure, "was called with the parameter", x)
+return false
+}
+
+baz :: proc{foo, bar}
+
+x := [3]int{1, 2, 3}
+y := [2]int{4, 9}
+ok_x := baz(x)
+ok_y := baz(y)
+assert(ok_x == true)
+assert(ok_y == false)
+}
+
+{ // Record types
+Foo :: struct($T: typeid, $N: int)
+where intrinsics.type_is_integer(T),
+N > 2 {
+x: [N]T,
+y: [N-2]T,
+}
+
+T :: i32
+N :: 5
+f: Foo(T, N)
+#assert(size_of(f) == (N+N-2)*size_of(T))
+}
+}
+
+
+when ODIN_OS == .Windows {
+foreign import kernel32 "system:kernel32.lib"
+}
+
+foreign_system :: proc() {
+fmt.println("\n#foreign system")
+when ODIN_OS == .Windows {
+// It is sometimes necessarily to interface with foreign code,
+// such as a C library. In Odin, this is achieved through the
+// foreign system. You can “import” a library into the code
+// using the same semantics as a normal import declaration.
+
+// This foreign import declaration will create a
+// “foreign import name” which can then be used to associate
+// entities within a foreign block.
+
+foreign kernel32 {
+ExitProcess :: proc "stdcall" (exit_code: u32) ---
+}
+
+// Foreign procedure declarations have the cdecl/c calling
+// convention by default unless specified otherwise. Due to
+// foreign procedures do not have a body declared within this
+// code, you need append the --- symbol to the end to distinguish
+// it as a procedure literal without a body and not a procedure type.
+
+// The attributes system can be used to change specific properties
+// of entities declared within a block:
+
+@(default_calling_convention = "std")
+foreign kernel32 {
+@(link_name="GetLastError") get_last_error :: proc() -> i32 ---
+}
+
+// Example using the link_prefix attribute
+@(default_calling_convention = "std")
+@(link_prefix = "Get")
+foreign kernel32 {
+LastError :: proc() -> i32 ---
+}
+}
+}
+
+ranged_fields_for_array_compound_literals :: proc() {
+fmt.println("\n#ranged fields for array compound literals")
+{ // Normal Array Literal
+foo := [?]int{1, 4, 9, 16}
+fmt.println(foo)
+}
+{ // Indexed
+foo := [?]int{
+3 = 16,
+1 = 4,
+2 = 9,
+0 = 1,
+}
+fmt.println(foo)
+}
+{ // Ranges
+i := 2
+foo := [?]int {
+0 = 123,
+5..=9 = 54,
+10..<16 = i*3 + (i-1)*2,
+}
+#assert(len(foo) == 16)
+fmt.println(foo) // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
+}
+{ // Slice and Dynamic Array support
+i := 2
+foo_slice := []int {
+0 = 123,
+5..=9 = 54,
+10..<16 = i*3 + (i-1)*2,
+}
+assert(len(foo_slice) == 16)
+fmt.println(foo_slice) // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
+
+foo_dynamic_array := [dynamic]int {
+0 = 123,
+5..=9 = 54,
+10..<16 = i*3 + (i-1)*2,
+}
+assert(len(foo_dynamic_array) == 16)
+fmt.println(foo_dynamic_array) // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
+}
+}
+
+deprecated_attribute :: proc() {
+@(deprecated="Use foo_v2 instead")
+foo_v1 :: proc(x: int) {
+fmt.println("foo_v1")
+}
+foo_v2 :: proc(x: int) {
+fmt.println("foo_v2")
+}
+
+// NOTE: Uncomment to see the warning messages
+// foo_v1(1)
+}
+
+range_statements_with_multiple_return_values :: proc() {
+fmt.println("\n#range statements with multiple return values")
+My_Iterator :: struct {
+index: int,
+data: []i32,
+}
+make_my_iterator :: proc(data: []i32) -> My_Iterator {
+return My_Iterator{data = data}
+}
+my_iterator :: proc(it: ^My_Iterator) -> (val: i32, idx: int, cond: bool) {
+if cond = it.index < len(it.data); cond {
+val = it.data[it.index]
+idx = it.index
+it.index += 1
+}
+return
+}
+
+data := make([]i32, 6)
+for _, i in data {
+data[i] = i32(i*i)
+}
+
+{ // Manual Style
+it := make_my_iterator(data)
+for {
+val, _, cond := my_iterator(&it)
+if !cond {
+break
+}
+fmt.println(val)
+}
+}
+{ // or_break
+it := make_my_iterator(data)
+loop: for {
+val, _ := my_iterator(&it) or_break loop
+fmt.println(val)
+}
+}
+{ // first value
+it := make_my_iterator(data)
+for val in my_iterator(&it) {
+fmt.println(val)
+}
+}
+{ // first and second value
+it := make_my_iterator(data)
+for val, idx in my_iterator(&it) {
+fmt.println(val, idx)
+}
+}
+}
+
+
+soa_struct_layout :: proc() {
+fmt.println("\n#SOA Struct Layout")
+
+{
+Vector3 :: struct {x, y, z: f32}
+
+N :: 2
+v_aos: [N]Vector3
+v_aos[0].x = 1
+v_aos[0].y = 4
+v_aos[0].z = 9
+
+fmt.println(len(v_aos))
+fmt.println(v_aos[0])
+fmt.println(v_aos[0].x)
+fmt.println(&v_aos[0].x)
+
+v_aos[1] = {0, 3, 4}
+v_aos[1].x = 2
+fmt.println(v_aos[1])
+fmt.println(v_aos)
+
+v_soa: #soa[N]Vector3
+
+v_soa[0].x = 1
+v_soa[0].y = 4
+v_soa[0].z = 9
+
+
+// Same syntax as AOS and treat as if it was an array
+fmt.println(len(v_soa))
+fmt.println(v_soa[0])
+fmt.println(v_soa[0].x)
+fmt.println(&v_soa[0].x)
+v_soa[1] = {0, 3, 4}
+v_soa[1].x = 2
+fmt.println(v_soa[1])
+
+// Can use SOA syntax if necessary
+v_soa.x[0] = 1
+v_soa.y[0] = 4
+v_soa.z[0] = 9
+fmt.println(v_soa.x[0])
+
+// Same pointer addresses with both syntaxes
+assert(&v_soa[0].x == &v_soa.x[0])
+
+
+// Same fmt printing
+fmt.println(v_aos)
+fmt.println(v_soa)
+}
+{
+// Works with arrays of length <= 4 which have the implicit fields xyzw/rgba
+Vector3 :: distinct [3]f32
+
+N :: 2
+v_aos: [N]Vector3
+v_aos[0].x = 1
+v_aos[0].y = 4
+v_aos[0].z = 9
+
+v_soa: #soa[N]Vector3
+
+v_soa[0].x = 1
+v_soa[0].y = 4
+v_soa[0].z = 9
+}
+{
+// SOA Slices
+// Vector3 :: struct {x, y, z: f32}
+Vector3 :: struct {x: i8, y: i16, z: f32}
+
+N :: 3
+v: #soa[N]Vector3
+v[0].x = 1
+v[0].y = 4
+v[0].z = 9
+
+s: #soa[]Vector3
+s = v[:]
+assert(len(s) == N)
+fmt.println(s)
+fmt.println(s[0].x)
+
+a := s[1:2]
+assert(len(a) == 1)
+fmt.println(a)
+
+d: #soa[dynamic]Vector3
+
+append_soa(&d, Vector3{1, 2, 3}, Vector3{4, 5, 9}, Vector3{-4, -4, 3})
+fmt.println(d)
+fmt.println(len(d))
+fmt.println(cap(d))
+fmt.println(d[:])
+}
+{ // soa_zip and soa_unzip
+fmt.println("\nsoa_zip and soa_unzip")
+
+x := []i32{1, 3, 9}
+y := []f32{2, 4, 16}
+z := []b32{true, false, true}
+
+// produce an #soa slice the normal slices passed
+s := soa_zip(a=x, b=y, c=z)
+
+// iterate over the #soa slice
+for v, i in s {
+fmt.println(v, i) // exactly the same as s[i]
+// NOTE: 'v' is NOT a temporary value but has a specialized addressing mode
+// which means that when accessing v.a etc, it does the correct transformation
+// internally:
+// s[i].a === s.a[i]
+fmt.println(v.a, v.b, v.c)
+}
+
+// Recover the slices from the #soa slice
+a, b, c := soa_unzip(s)
+fmt.println(a, b, c)
+}
+}
+
+constant_literal_expressions :: proc() {
+fmt.println("\n#constant literal expressions")
+
+Bar :: struct {x, y: f32}
+Foo :: struct {a, b: int, using c: Bar}
+
+FOO_CONST :: Foo{b = 2, a = 1, c = {3, 4}}
+
+
+fmt.println(FOO_CONST.a)
+fmt.println(FOO_CONST.b)
+fmt.println(FOO_CONST.c)
+fmt.println(FOO_CONST.c.x)
+fmt.println(FOO_CONST.c.y)
+fmt.println(FOO_CONST.x) // using works as expected
+fmt.println(FOO_CONST.y)
+
+fmt.println("-------")
+
+ARRAY_CONST :: [3]int{1 = 4, 2 = 9, 0 = 1}
+
+fmt.println(ARRAY_CONST[0])
+fmt.println(ARRAY_CONST[1])
+fmt.println(ARRAY_CONST[2])
+
+fmt.println("-------")
+
+FOO_ARRAY_DEFAULTS :: [3]Foo{{}, {}, {}}
+fmt.println(FOO_ARRAY_DEFAULTS[2].x)
+
+fmt.println("-------")
+
+Baz :: enum{A=5, B, C, D}
+ENUM_ARRAY_CONST :: [Baz]int{.A ..= .C = 1, .D = 16}
+
+fmt.println(ENUM_ARRAY_CONST[.A])
+fmt.println(ENUM_ARRAY_CONST[.B])
+fmt.println(ENUM_ARRAY_CONST[.C])
+fmt.println(ENUM_ARRAY_CONST[.D])
+
+fmt.println("-------")
+
+Sparse_Baz :: enum{A=5, B, C, D=16}
+#assert(len(Sparse_Baz) < len(#sparse[Sparse_Baz]int))
+SPARSE_ENUM_ARRAY_CONST :: #sparse[Sparse_Baz]int{.A ..= .C = 1, .D = 16}
+
+fmt.println(SPARSE_ENUM_ARRAY_CONST[.A])
+fmt.println(SPARSE_ENUM_ARRAY_CONST[.B])
+fmt.println(SPARSE_ENUM_ARRAY_CONST[.C])
+fmt.println(SPARSE_ENUM_ARRAY_CONST[.D])
+
+fmt.println("-------")
+
+
+STRING_CONST :: "Hellope!"
+
+fmt.println(STRING_CONST[0])
+fmt.println(STRING_CONST[2])
+fmt.println(STRING_CONST[3])
+
+fmt.println(STRING_CONST[0:5])
+fmt.println(STRING_CONST[3:][:4])
+}
+
+union_maybe :: proc() {
+fmt.println("\n#union based maybe")
+
+// NOTE: This is already built-in, and this is just a reimplementation to explain the behaviour
+Maybe :: union($T: typeid) {T}
+
+i: Maybe(u8)
+p: Maybe(^u8) // No tag is stored for pointers, nil is the sentinel value
+
+// Tag size will be as small as needed for the number of variants
+#assert(size_of(i) == size_of(u8) + size_of(u8))
+// No need to store a tag here, the `nil` state is shared with the variant's `nil`
+#assert(size_of(p) == size_of(^u8))
+
+i = 123
+x := i.?
+y, y_ok := p.?
+p = &x
+z, z_ok := p.?
+
+fmt.println(i, p)
+fmt.println(x, &x)
+fmt.println(y, y_ok)
+fmt.println(z, z_ok)
+}
+
+dummy_procedure :: proc() {
+fmt.println("dummy_procedure")
+}
+
+explicit_context_definition :: proc "c" () {
+// Try commenting the following statement out below
+context = runtime.default_context()
+
+fmt.println("\n#explicit context definition")
+dummy_procedure()
+}
+
+or_else_operator :: proc() {
+fmt.println("\n#'or_else'")
+{
+m: map[string]int
+i: int
+ok: bool
+
+if i, ok = m["hellope"]; !ok {
+i = 123
+}
+// The above can be mapped to 'or_else'
+i = m["hellope"] or_else 123
+
+assert(i == 123)
+}
+{
+// 'or_else' can be used with type assertions too, as they
+// have optional ok semantics
+v: union{int, f64}
+i: int
+i = v.(int) or_else 123
+i = v.? or_else 123 // Type inference magic
+assert(i == 123)
+
+m: Maybe(int)
+i = m.? or_else 456
+assert(i == 456)
+}
+}
+
+or_return_operator :: proc() {
+fmt.println("\n#'or_return'")
+// The concept of 'or_return' will work by popping off the end value in a multiple
+// valued expression and checking whether it was not 'nil' or 'false', and if so,
+// set the end return value to value if possible. If the procedure only has one
+// return value, it will do a simple return. If the procedure had multiple return
+// values, 'or_return' will require that all parameters be named so that the end
+// value could be assigned to by name and then an empty return could be called.
+
+Error :: enum {
+None,
+Something_Bad,
+Something_Worse,
+The_Worst,
+Your_Mum,
+}
+
+caller_1 :: proc() -> Error {
+return .None
+}
+
+caller_2 :: proc() -> (int, Error) {
+return 123, .None
+}
+caller_3 :: proc() -> (int, int, Error) {
+return 123, 345, .None
+}
+
+foo_1 :: proc() -> Error {
+// This can be a common idiom in many code bases
+n0, err := caller_2()
+if err != nil {
+return err
+}
+
+// The above idiom can be transformed into the following
+n1 := caller_2() or_return
+
+
+// And if the expression is 1-valued, it can be used like this
+caller_1() or_return
+// which is functionally equivalent to
+if err1 := caller_1(); err1 != nil {
+return err1
+}
+
+// Multiple return values still work with 'or_return' as it only
+// pops off the end value in the multi-valued expression
+n0, n1 = caller_3() or_return
+
+return .None
+}
+foo_2 :: proc() -> (n: int, err: Error) {
+// It is more common that your procedure returns multiple values
+// If 'or_return' is used within a procedure multiple parameters (2+),
+// then all the parameters must be named so that the remaining parameters
+// so that a bare 'return' statement can be used
+
+// This can be a common idiom in many code bases
+x: int
+x, err = caller_2()
+if err != nil {
+return
+}
+
+// The above idiom can be transformed into the following
+y := caller_2() or_return
+_ = y
+
+// And if the expression is 1-valued, it can be used like this
+caller_1() or_return
+
+// which is functionally equivalent to
+if err1 := caller_1(); err1 != nil {
+err = err1
+return
+}
+
+// If using a non-bare 'return' statement is required, setting the return values
+// using the normal idiom is a better choice and clearer to read.
+if z, zerr := caller_2(); zerr != nil {
+return -345 * z, zerr
+}
+
+defer if err != nil {
+fmt.println("Error in", #procedure, ":" , err)
+}
+
+n = 123
+return
+}
+
+foo_1()
+foo_2()
+}
+
+
+or_break_and_or_continue_operators :: proc() {
+fmt.println("\n#'or_break' and 'or_continue'")
+// The concept of 'or_break' and 'or_continue' is very similar to that of 'or_return'.
+// The difference is that unlike 'or_return', the value does not get returned from
+// the current procedure but rather discarded if it is 'false' or not 'nil', and then
+// the specified branch (i.e. break or continue).
+// The or branch expression can be labelled if a specific statement needs to be used.
+
+Error :: enum {
+None,
+Something_Bad,
+Something_Worse,
+The_Worst,
+Your_Mum,
+}
+
+caller_1 :: proc() -> Error {
+return .Something_Bad
+}
+
+caller_2 :: proc() -> (int, Error) {
+return 123, .Something_Worse
+}
+caller_3 :: proc() -> (int, int, Error) {
+return 123, 345, .None
+}
+
+for { // common approach
+err := caller_1()
+if err != nil {
+break
+}
+}
+for { // or_break approach
+caller_1() or_break
+}
+
+for { // or_break approach with multiple values
+n := caller_2() or_break
+_ = n
+}
+
+loop: for { // or_break approach with named label
+n := caller_2() or_break loop
+_ = n
+}
+
+for { // or_continue
+x, y := caller_3() or_continue
+_, _ = x, y
+
+break
+}
+
+continue_loop: for { // or_continue with named label
+x, y := caller_3() or_continue continue_loop
+_, _ = x, y
+
+break
+}
+
+}
+
+arbitrary_precision_mathematics :: proc() {
+fmt.println("\n# core:math/big")
+
+print_bigint :: proc(name: string, a: ^big.Int, base := i8(10), print_name := true, newline := true, print_extra_info := true) {
+big.assert_if_nil(a)
+
+as, err := big.itoa(a, base)
+defer delete(as)
+
+cb := big.internal_count_bits(a)
+if print_name {
+fmt.print(name)
+}
+if err != nil {
+fmt.printf(" (Error: %v) ", err)
+}
+fmt.printf(as)
+if print_extra_info {
+fmt.printf(" (base: %v, bits: %v, digits: %v)", base, cb, a.used)
+}
+if newline {
+fmt.println()
+}
+}
+
+a, b, c, d, e, f, res := &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}
+defer big.destroy(a, b, c, d, e, f, res)
+
+// Set the context RNG to something that does not require
+// cryptographic entropy (not supported on all targets).
+context.random_generator = rand.xoshiro256_random_generator()
+
+// How many bits should the random prime be?
+bits := 64
+// Number of Rabin-Miller trials, -1 for automatic.
+trials := -1
+
+// Default prime generation flags
+flags := big.Primality_Flags{}
+
+err := big.internal_random_prime(a, bits, trials, flags)
+if err != nil {
+fmt.printf("Error %v while generating random prime.\n", err)
+} else {
+print_bigint("Random Prime A: ", a, 10)
+fmt.printf("Random number iterations until prime found: %v\n", big.RANDOM_PRIME_ITERATIONS_USED)
+}
+
+// If we want to pack this Int into a buffer of u32, how many do we need?
+count := big.internal_int_pack_count(a, u32)
+buf := make([]u32, count)
+defer delete(buf)
+
+written: int
+written, err = big.internal_int_pack(a, buf)
+fmt.printf("\nPacked into u32 buf: %v | err: %v | written: %v\n", buf, err, written)
+
+// If we want to pack this Int into a buffer of bytes of which only the bottom 6 bits are used, how many do we need?
+nails := 2
+
+count = big.internal_int_pack_count(a, u8, nails)
+byte_buf := make([]u8, count)
+defer delete(byte_buf)
+
+written, err = big.internal_int_pack(a, byte_buf, nails)
+fmt.printf("\nPacked into buf of 6-bit bytes: %v | err: %v | written: %v\n", byte_buf, err, written)
+
+
+
+// Pick another random big Int, not necesssarily prime.
+err = big.random(b, 2048)
+print_bigint("\n2048 bit random number: ", b)
+
+// Calculate GCD + LCM in one fell swoop
+big.gcd_lcm(c, d, a, b)
+
+print_bigint("\nGCD of random prime A and random number B: ", c)
+print_bigint("\nLCM of random prime A and random number B (in base 36): ", d, 36)
+}
+
+matrix_type :: proc() {
+fmt.println("\n# matrix type")
+// A matrix is a mathematical type built into Odin. It is a regular array of numbers,
+// arranged in rows and columns
+
+{
+// The following represents a matrix that has 2 rows and 3 columns
+m: matrix[2, 3]f32
+
+m = matrix[2, 3]f32{
+1, 9, -13,
+20, 5, -6,
+}
+
+// Element types of integers, float, and complex numbers are supported by matrices.
+// There is no support for booleans, quaternions, or any compound type.
+
+// Indexing a matrix can be used with the matrix indexing syntax
+// This mirrors other type usages: type on the left, usage on the right
+
+elem := m[1, 2] // row 1, column 2
+assert(elem == -6)
+
+
+// Scalars act as if they are scaled identity matrices
+// and can be assigned to matrices as them
+b := matrix[2, 2]f32{}
+f := f32(3)
+b = f
+
+fmt.println("b", b)
+fmt.println("b == f", b == f)
+
+}
+
+{ // Matrices support multiplication between matrices
+a := matrix[2, 3]f32{
+2, 3, 1,
+4, 5, 0,
+}
+
+b := matrix[3, 2]f32{
+1, 2,
+3, 4,
+5, 6,
+}
+
+fmt.println("a", a)
+fmt.println("b", b)
+
+c := a * b
+#assert(type_of(c) == matrix[2, 2]f32)
+fmt.println("c = a * b", c)
+}
+
+{ // Matrices support multiplication between matrices and arrays
+m := matrix[4, 4]f32{
+1, 2, 3, 4,
+5, 5, 4, 2,
+0, 1, 3, 0,
+0, 1, 4, 1,
+}
+
+v := [4]f32{1, 5, 4, 3}
+
+// treating 'v' as a column vector
+fmt.println("m * v", m * v)
+
+// treating 'v' as a row vector
+fmt.println("v * m", v * m)
+
+// Support with non-square matrices
+s := matrix[2, 4]f32{ // [4][2]f32
+2, 4, 3, 1,
+7, 8, 6, 5,
+}
+
+w := [2]f32{1, 2}
+r: [4]f32 = w * s
+fmt.println("r", r)
+}
+
+{ // Component-wise operations
+// if the element type supports it
+// Not support for '/', '%', or '%%' operations
+
+a := matrix[2, 2]i32{
+1, 2,
+3, 4,
+}
+
+b := matrix[2, 2]i32{
+-5, 1,
+9, -7,
+}
+
+c0 := a + b
+c1 := a - b
+c2 := a & b
+c3 := a | b
+c4 := a ~ b
+c5 := a &~ b
+
+// component-wise multiplication
+// since a * b would be a standard matrix multiplication
+c6 := intrinsics.hadamard_product(a, b)
+
+
+fmt.println("a + b", c0)
+fmt.println("a - b", c1)
+fmt.println("a & b", c2)
+fmt.println("a | b", c3)
+fmt.println("a ~ b", c4)
+fmt.println("a &~ b", c5)
+fmt.println("hadamard_product(a, b)", c6)
+}
+
+{ // Submatrix casting square matrices
+// Casting a square matrix to another square matrix with same element type
+// is supported.
+// If the cast is to a smaller matrix type, the top-left submatrix is taken.
+// If the cast is to a larger matrix type, the matrix is extended with zeros
+// everywhere and ones in the diagonal for the unfilled elements of the
+// extended matrix.
+
+mat2 :: distinct matrix[2, 2]f32
+mat4 :: distinct matrix[4, 4]f32
+
+m2 := mat2{
+1, 3,
+2, 4,
+}
+
+m4 := mat4(m2)
+assert(m4[2, 2] == 1)
+assert(m4[3, 3] == 1)
+fmt.printf("m2 %#v\n", m2)
+fmt.println("m4", m4)
+fmt.println("mat2(m4)", mat2(m4))
+assert(mat2(m4) == m2)
+
+b4 := mat4{
+1, 2, 0, 0,
+3, 4, 0, 0,
+5, 0, 6, 0,
+0, 7, 0, 8,
+}
+fmt.println("b4", intrinsics.matrix_flatten(b4))
+}
+
+{ // Casting non-square matrices
+// Casting a matrix to another matrix is allowed as long as they share
+// the same element type and the number of elements (rows*columns).
+// Matrices in Odin are stored in column-major order, which means
+// the casts will preserve this element order.
+
+mat2x4 :: distinct matrix[2, 4]f32
+mat4x2 :: distinct matrix[4, 2]f32
+
+x := mat2x4{
+1, 3, 5, 7,
+2, 4, 6, 8,
+}
+
+y := mat4x2(x)
+fmt.println("x", x)
+fmt.println("y", y)
+}
+
+// TECHNICAL INFORMATION: the internal representation of a matrix in Odin is stored
+// in column-major format
+// e.g. matrix[2, 3]f32 is internally [3][2]f32 (with different a alignment requirement)
+// Column-major is used in order to utilize (SIMD) vector instructions effectively on
+// modern hardware, if possible.
+//
+// Unlike normal arrays, matrices try to maximize alignment to allow for the (SIMD) vectorization
+// properties whilst keeping zero padding (either between columns or at the end of the type).
+//
+// Zero padding is a compromise for use with third-party libraries, instead of optimizing for performance.
+// Padding between columns was not taken even if that would have allowed each column to be loaded
+// individually into a SIMD register with the correct alignment properties.
+//
+// Currently, matrices are limited to a maximum of 16 elements (rows*columns), and a minimum of 1 element.
+// This is because matrices are stored as values (not a reference type), and thus operations on them will
+// be stored on the stack. Restricting the maximum element count minimizing the possibility of stack overflows.
+
+// 'intrinsics' Procedures (Compiler Level)
+// transpose(m)
+// transposes a matrix
+// outer_product(a, b)
+// takes two array-like data types and returns the outer product
+// of the values in a matrix
+// hadamard_product(a, b)
+// component-wise multiplication of two matrices of the same type
+// matrix_flatten(m)
+// converts the matrix into a flatten array of elements
+// in column-major order
+// Example:
+// m := matrix[2, 2]f32{
+// x0, x1,
+// y0, y1,
+// }
+// array: [4]f32 = matrix_flatten(m)
+// assert(array == {x0, y0, x1, y1})
+// conj(x)
+// conjugates the elements of a matrix for complex element types only
+
+// Procedures in "core:math/linalg" and related (Runtime Level) (all square matrix procedures)
+// determinant(m)
+// adjugate(m)
+// inverse(m)
+// inverse_transpose(m)
+// hermitian_adjoint(m)
+// trace(m)
+// matrix_minor(m)
+}
+
+bit_field_type :: proc() {
+fmt.println("\n# bit_field type")
+// A `bit_field` is a record type in Odin that is akin to a bit-packed struct.
+// IMPORTNAT NOTE: `bit_field` is NOT equivalent to `bit_set` as it has different sematics and use cases.
+
+{
+// `bit_field` fields are accessed by using a dot:
+Foo :: bit_field u16 { // backing type must be an integer or array of integers
+x: i32 | 3, // signed integers will be signed extended on use
+y: u16 | 2 + 3, // general expressions
+z: My_Enum | SOME_CONSTANT, // ability to define the bit-width elsewhere
+w: bool | 2 when SOME_CONSTANT > 10 else 1,
+}
+
+v := Foo{}
+v.x = 3 // truncates the value to fit into 3 bits
+fmt.println(v.x) // accessing will convert `v.x` to an `i32` and do an appropriate sign extension
+
+
+My_Enum :: enum u8 {A, B, C, D}
+SOME_CONSTANT :: 7
+}
+
+{
+// A `bit_field` is different from a struct in that you must specify the backing type.
+// This backing type must be an integer or a fixed-length array of integers.
+// This is useful if there needs to be a specific alignment or access pattern for the record.
+
+Bar :: bit_field u32 {}
+Baz :: bit_field [4]u8 {}
+}
+
+// IMPORTANT NOTES:
+// * If _all_ of the fields in a bit_field are 1-bit in size and they are all booleans,
+// please consider using a `bit_set` instead.
+// * Odin's `bit_field` and C's bit-fields might not be compatible
+// * Odin's `bit_field`s have a well defined layout (Least-Significant-Bit)
+// * C's bit-fields on `struct`s are undefined and are not portable across targets and compilers
+// * A `bit_field`'s field type can only be one of the following:
+// * Integer
+// * Boolean
+// * Enum
+}
+
+main :: proc() {
+/*
+For More Odin Examples - https://github.com/odin-lang/examples
+This repository contains examples of how certain things can be accomplished
+in idiomatic Odin, allowing you learn its semantics, as well as how to use
+parts of the core and vendor package collections.
+*/
+
+when true {
+the_basics()
+control_flow()
+named_proc_return_parameters()
+variadic_procedures()
+explicit_procedure_overloading()
+struct_type()
+union_type()
+using_statement()
+implicit_context_system()
+parametric_polymorphism()
+threading_example()
+array_programming()
+map_type()
+implicit_selector_expression()
+partial_switch()
+cstring_example()
+bit_set_type()
+deferred_procedure_associations()
+reflection()
+quaternions()
+unroll_for_statement()
+where_clauses()
+foreign_system()
+ranged_fields_for_array_compound_literals()
+deprecated_attribute()
+range_statements_with_multiple_return_values()
+soa_struct_layout()
+constant_literal_expressions()
+union_maybe()
+explicit_context_definition()
+or_else_operator()
+or_return_operator()
+or_break_and_or_continue_operators()
+arbitrary_precision_mathematics()
+matrix_type()
+bit_field_type()
+}
+}
+// END_INDENT
--- /dev/null
+// vim: set ft=odin sw=4 ts=8 et:
+
+// START_INDENT
+
+#+vet !using-stmt !using-param
+#+feature dynamic-literals using-stmt
+package main
+
+import "core:fmt"
+import "core:mem"
+import "core:os"
+import "core:thread"
+import "core:time"
+import "core:reflect"
+import "base:runtime"
+import "base:intrinsics"
+import "core:math/big"
+import "core:math/rand"
+
+/*
+ Odin is a general-purpose programming language with distinct typing built
+ for high performance, modern systems and data-oriented programming.
+
+ Odin is the C alternative for the Joy of Programming.
+
+ # Installing Odin
+ Getting Started - https://odin-lang.org/docs/install/
+ Instructions for downloading and install the Odin compiler and libraries.
+
+ # Learning Odin
+ Getting Started - https://odin-lang.org/docs/install/
+ Getting Started with Odin. Downloading, installing, and getting your
+ first program to compile and run.
+ Overview of Odin - https://odin-lang.org/docs/overview/
+ An overview of the Odin programming language and its features.
+ Frequently Asked Questions (FAQ) - https://odin-lang.org/docs/faq/
+ Answers to common questions about Odin.
+ Packages - https://pkg.odin-lang.org/
+ Documentation for all the official packages part of the
+ core and vendor library collections.
+ Nightly Builds - https://odin-lang.org/docs/nightly/
+ Get the latest nightly builds of Odin.
+ More Odin Examples - https://github.com/odin-lang/examples
+ This repository contains examples of how certain things can be accomplished
+ in idiomatic Odin, allowing you learn its semantics, as well as how to use
+ parts of the core and vendor package collections.
+ */
+
+the_basics :: proc() {
+ fmt.println("\n# the basics")
+
+ { // The Basics
+
+ // os.args holds the path to the current executable and any arguments passed to it.
+ if len(os.args) == 1 {
+ fmt.printf("Hellope from %v.\n", os.args[0])
+ } else if len(os.args) > 2 {
+ fmt.printf("%v, %v! from %v.\n", os.args[1], os.args[2], os.args[0])
+ }
+
+ // Lexical elements and literals
+ // A comment
+
+ my_integer_variable: int // A comment for documentaton
+
+ // Multi-line comments begin with /* and end with */. Multi-line comments can
+ // also be nested (unlike in C):
+ /*
+ You can have any text or code here and
+ have it be commented.
+ /*
+ NOTE: comments can be nested!
+ */
+ */
+
+ // String literals are enclosed in double quotes and character literals in single quotes.
+ // Special characters are escaped with a backslash \
+
+ some_string := "This is a string"
+ _ = 'A' // unicode codepoint literal
+ _ = '\n'
+ _ = "C:\\Windows\\notepad.exe"
+ // Raw string literals are enclosed with single back ticks
+ _ = `C:\Windows\notepad.exe`
+
+ // The length of a string in bytes can be found using the built-in `len` procedure:
+ _ = len("Foo")
+ _ = len(some_string)
+
+
+ // Numbers
+
+ // Numerical literals are written similar to most other programming languages.
+ // A useful feature in Odin is that underscores are allowed for better
+ // readability: 1_000_000_000 (one billion). A number that contains a dot is a
+ // floating point literal: 1.0e9 (one billion). If a number literal is suffixed
+ // with i, is an imaginary number literal: 2i (2 multiply the square root of -1).
+
+ // Binary literals are prefixed with 0b, octal literals with 0o, and hexadecimal
+ // literals 0x. A leading zero does not produce an octal constant (unlike C).
+
+ // In Odin, if a numeric constant can be represented by a type without
+ // precision loss, it will automatically convert to that type.
+
+ x: int = 1.0 // A float literal but it can be represented by an integer without precision loss
+ // Constant literals are “untyped” which means that they can implicitly convert to a type.
+
+ y: int // `y` is typed of type `int`
+ y = 1 // `1` is an untyped integer literal which can implicitly convert to `int`
+
+ z: f64 // `z` is typed of type `f64` (64-bit floating point number)
+ z = 1 // `1` is an untyped integer literal which can be implicitly converted to `f64`
+ // No need for any suffixes or decimal places like in other languages
+ // (with the exception of negative zero, which must be given as `-0.0`)
+ // CONSTANTS JUST WORK!!!
+
+
+ // Assignment statements
+ h: int = 123 // declares a new variable `h` with type `int` and assigns a value to it
+ h = 637 // assigns a new value to `h`
+
+ // `=` is the assignment operator
+
+ // You can assign multiple variables with it:
+ a, b := 1, "hello" // declares `a` and `b` and infers the types from the assignments
+ b, a = "byte", 0
+
+ // Note: `:=` is two tokens, `:` and `=`. The following are equivalent,
+ /*
+ i: int = 123
+ i: = 123
+ i := 123
+ */
+
+ // Constant declarations
+ // Constants are entities (symbols) which have an assigned value.
+ // The constant’s value cannot be changed.
+ // The constant’s value must be able to be evaluated at compile time:
+ X :: "what" // constant `X` has the untyped string value "what"
+
+ // Constants can be explicitly typed like a variable declaration:
+ Y : int : 123
+ Z :: Y + 7 // constant computations are possible
+
+ _ = my_integer_variable
+ _ = x
+ }
+}
+
+control_flow :: proc() {
+ fmt.println("\n# control flow")
+ { // Control flow
+ // For loop
+ // Odin has only one loop statement, the `for` loop
+
+ // Basic for loop
+ for i := 0; i < 10; i += 1 {
+ fmt.println(i)
+ }
+
+ // NOTE: Unlike other languages like C, there are no parentheses `( )` surrounding the three components.
+ // Braces `{ }` or a `do` are always required
+ for i := 0; i < 10; i += 1 { }
+ // for i := 0; i < 10; i += 1 do fmt.print()
+
+ // The initial and post statements are optional
+ i := 0
+ for ; i < 10; {
+ i += 1
+ }
+
+ // These semicolons can be dropped. This `for` loop is equivalent to C's `while` loop
+ i = 0
+ for i < 10 {
+ i += 1
+ }
+
+ // If the condition is omitted, an infinite loop is produced:
+ for {
+ break
+ }
+
+ // Range-based for loop
+ // The basic for loop
+ for j := 0; j < 10; j += 1 {
+ fmt.println(j)
+ }
+ // can also be written
+ for j in 0..<10 {
+ fmt.println(j)
+ }
+ for j in 0..=9 {
+ fmt.println(j)
+ }
+
+ // Certain built-in types can be iterated over
+ some_string := "Hello, 世界"
+ for character in some_string { // Strings are assumed to be UTF-8
+ fmt.println(character)
+ }
+
+ some_array := [3]int{1, 4, 9}
+ for value in some_array {
+ fmt.println(value)
+ }
+
+ some_slice := []int{1, 4, 9}
+ for value in some_slice {
+ fmt.println(value)
+ }
+
+ some_dynamic_array := [dynamic]int{1, 4, 9}
+ defer delete(some_dynamic_array)
+ for value in some_dynamic_array {
+ fmt.println(value)
+ }
+
+
+ some_map := map[string]int{"A" = 1, "C" = 9, "B" = 4}
+ defer delete(some_map)
+ for key in some_map {
+ fmt.println(key)
+ }
+
+ // Alternatively a second index value can be added
+ for character, index in some_string {
+ fmt.println(index, character)
+ }
+ for value, index in some_array {
+ fmt.println(index, value)
+ }
+ for value, index in some_slice {
+ fmt.println(index, value)
+ }
+ for value, index in some_dynamic_array {
+ fmt.println(index, value)
+ }
+ for key, value in some_map {
+ fmt.println(key, value)
+ }
+
+ // The iterated values are copies and cannot be written to.
+ // The following idiom is useful for iterating over a container in a by-reference manner:
+ for _, idx in some_slice {
+ some_slice[idx] = (idx+1)*(idx+1)
+ }
+
+
+ // If statements
+ x := 123
+ if x >= 0 {
+ fmt.println("x is positive")
+ }
+
+ if y := -34; y < 0 {
+ fmt.println("y is negative")
+ }
+
+ if y := 123; y < 0 {
+ fmt.println("y is negative")
+ } else if y == 0 {
+ fmt.println("y is zero")
+ } else {
+ fmt.println("y is positive")
+ }
+
+ // Switch statement
+ // A switch statement is another way to write a sequence of if-else statements.
+ // In Odin, the default case is denoted as a case without any expression.
+
+ #partial switch arch := ODIN_ARCH; arch {
+ case .i386:
+ fmt.println("32-bit")
+ case .amd64:
+ fmt.println("64-bit")
+ case: // default
+ fmt.println("Unsupported architecture")
+ }
+
+ // Odin’s `switch` is like one in C or C++, except that Odin only runs the selected case.
+ // This means that a `break` statement is not needed at the end of each case.
+ // Another important difference is that the case values need not be integers nor constants.
+
+ // To achieve a C-like fall through into the next case block, the keyword `fallthrough` can be used.
+ one_angry_dwarf :: proc() -> int {
+ fmt.println("one_angry_dwarf was called")
+ return 1
+ }
+
+ switch j := 0; j {
+ case 0:
+ case one_angry_dwarf():
+ }
+
+ // A switch statement without a condition is the same as `switch true`.
+ // This can be used to write a clean and long if-else chain and have the
+ // ability to break if needed
+
+ switch {
+ case x < 0:
+ fmt.println("x is negative")
+ case x == 0:
+ fmt.println("x is zero")
+ case:
+ fmt.println("x is positive")
+ }
+
+ // A `switch` statement can also use ranges like a range-based loop:
+ switch c := 'j'; c {
+ case 'A'..='Z', 'a'..='z', '0'..='9':
+ fmt.println("c is alphanumeric")
+ }
+
+ switch x {
+ case 0..<10:
+ fmt.println("units")
+ case 10..<13:
+ fmt.println("pre-teens")
+ case 13..<20:
+ fmt.println("teens")
+ case 20..<30:
+ fmt.println("twenties")
+ }
+ }
+
+ { // Defer statement
+ // A defer statement defers the execution of a statement until the end of
+ // the scope it is in.
+
+ // The following will print 4 then 234:
+ {
+ x := 123
+ defer fmt.println(x)
+ {
+ defer x = 4
+ x = 2
+ }
+ fmt.println(x)
+
+ x = 234
+ }
+
+ // You can defer an entire block too:
+ {
+ bar :: proc() {}
+
+ defer {
+ fmt.println("1")
+ fmt.println("2")
+ }
+
+ cond := false
+ defer if cond {
+ bar()
+ }
+ }
+
+ // Defer statements are executed in the reverse order that they were declared:
+ {
+ defer fmt.println("1")
+ defer fmt.println("2")
+ defer fmt.println("3")
+ }
+ // Will print 3, 2, and then 1.
+
+ if false {
+ f, err := os.open("my_file.txt")
+ if err != nil {
+ // handle error
+ }
+ defer os.close(f)
+ // rest of code
+ }
+ }
+
+ { // When statement
+ /*
+ The when statement is almost identical to the if statement but with some differences:
+
+ * Each condition must be a constant expression as a when
+ statement is evaluated at compile time.
+ * The statements within a branch do not create a new scope
+ * The compiler checks the semantics and code only for statements
+ that belong to the first condition that is true
+ * An initial statement is not allowed in a when statement
+ * when statements are allowed at file scope
+ */
+
+ // Example
+ when ODIN_ARCH == .i386 {
+ fmt.println("32 bit")
+ } else when ODIN_ARCH == .amd64 {
+ fmt.println("64 bit")
+ } else {
+ fmt.println("Unknown architecture")
+ }
+ // The when statement is very useful for writing platform specific code.
+ // This is akin to the #if construct in C’s preprocessor however, in Odin,
+ // it is type checked.
+ }
+
+ { // Branch statements
+ cond, cond1, cond2 := false, false, false
+ one_step :: proc() { fmt.println("one_step") }
+ beyond :: proc() { fmt.println("beyond") }
+
+ // Break statement
+ for cond {
+ switch {
+ case:
+ if cond {
+ break // break out of the `switch` statement
+ }
+ }
+
+ break // break out of the `for` statement
+ }
+
+ loop: for cond1 {
+ for cond2 {
+ break loop // leaves both loops
+ }
+ }
+
+ // Continue statement
+ for cond {
+ if cond2 {
+ continue
+ }
+ fmt.println("Hellope")
+ }
+
+ // Fallthrough statement
+
+ // Odin’s switch is like one in C or C++, except that Odin only runs the selected
+ // case. This means that a break statement is not needed at the end of each case.
+ // Another important difference is that the case values need not be integers nor
+ // constants.
+
+ // fallthrough can be used to explicitly fall through into the next case block:
+
+ switch i := 0; i {
+ case 0:
+ one_step()
+ fallthrough
+ case 1:
+ beyond()
+ }
+ }
+}
+
+
+named_proc_return_parameters :: proc() {
+ fmt.println("\n# named proc return parameters")
+
+ foo0 :: proc() -> int {
+ return 123
+ }
+ foo1 :: proc() -> (a: int) {
+ a = 123
+ return
+ }
+ foo2 :: proc() -> (a, b: int) {
+ // Named return values act like variables within the scope
+ a = 321
+ b = 567
+ return b, a
+ }
+ fmt.println("foo0 =", foo0()) // 123
+ fmt.println("foo1 =", foo1()) // 123
+ fmt.println("foo2 =", foo2()) // 567 321
+}
+
+variadic_procedures :: proc() {
+ fmt.println("\n# variadic procedures")
+ sum :: proc(nums: ..int, init_value:= 0) -> (result: int) {
+ result = init_value
+ for n in nums {
+ result += n
+ }
+ return
+ }
+ fmt.println("sum(()) =", sum())
+ fmt.println("sum(1, 2) =", sum(1, 2))
+ fmt.println("sum(1, 2, 3, 4, 5) =", sum(1, 2, 3, 4, 5))
+ fmt.println("sum(1, 2, 3, 4, 5, init_value = 5) =", sum(1, 2, 3, 4, 5, init_value = 5))
+
+ // pass a slice as varargs
+ odds := []int{1, 3, 5}
+ fmt.println("odds =", odds)
+ fmt.println("sum(..odds) =", sum(..odds))
+ fmt.println("sum(..odds, init_value = 5) =", sum(..odds, init_value = 5))
+}
+
+
+explicit_procedure_overloading :: proc() {
+ fmt.println("\n# explicit procedure overloading")
+
+ add_ints :: proc(a, b: int) -> int {
+ x := a + b
+ fmt.println("add_ints", x)
+ return x
+ }
+ add_floats :: proc(a, b: f32) -> f32 {
+ x := a + b
+ fmt.println("add_floats", x)
+ return x
+ }
+ add_numbers :: proc(a: int, b: f32, c: u8) -> int {
+ x := int(a) + int(b) + int(c)
+ fmt.println("add_numbers", x)
+ return x
+ }
+
+ add :: proc{add_ints, add_floats, add_numbers}
+
+ add(int(1), int(2))
+ add(f32(1), f32(2))
+ add(int(1), f32(2), u8(3))
+
+ add(1, 2) // untyped ints coerce to int tighter than f32
+ add(1.0, 2.0) // untyped floats coerce to f32 tighter than int
+ add(1, 2, 3) // three parameters
+
+ // Ambiguous answers
+ // add(1.0, 2)
+ // add(1, 2.0)
+}
+
+struct_type :: proc() {
+ fmt.println("\n# struct type")
+ // A struct is a record type in Odin. It is a collection of fields.
+ // Struct fields are accessed by using a dot:
+ {
+ Vector2 :: struct {
+ x: f32,
+ y: f32,
+ }
+ v := Vector2{1, 2}
+ v.x = 4
+ fmt.println(v.x)
+
+ // Struct fields can be accessed through a struct pointer:
+
+ v = Vector2{1, 2}
+ p := &v
+ p.x = 1335
+ fmt.println(v)
+
+ // We could write p^.x, however, it is nice to abstract the ability
+ // to not explicitly dereference the pointer. This is very useful when
+ // refactoring code to use a pointer rather than a value, and vice versa.
+ }
+ {
+ // A struct literal can be denoted by providing the struct’s type
+ // followed by {}. A struct literal must either provide all the
+ // arguments or none:
+ Vector3 :: struct {
+ x, y, z: f32,
+ }
+ v: Vector3
+ v = Vector3{} // Zero value
+ v = Vector3{1, 4, 9}
+
+ // You can list just a subset of the fields if you specify the
+ // field by name (the order of the named fields does not matter):
+ v = Vector3{z=1, y=2}
+ assert(v.x == 0)
+ assert(v.y == 2)
+ assert(v.z == 1)
+ }
+ {
+ // Structs can tagged with different memory layout and alignment requirements:
+
+ a :: struct #align(4) {} // align to 4 bytes
+ b :: struct #packed {} // remove padding between fields
+ c :: struct #raw_union {} // all fields share the same offset (0). This is the same as C's union
+ }
+
+}
+
+
+union_type :: proc() {
+ fmt.println("\n# union type")
+ {
+ val: union{int, bool}
+ val = 137
+ if i, ok := val.(int); ok {
+ fmt.println(i)
+ }
+ val = true
+ fmt.println(val)
+
+ val = nil
+
+ switch v in val {
+ case int: fmt.println("int", v)
+ case bool: fmt.println("bool", v)
+ case: fmt.println("nil")
+ }
+ }
+ {
+ // There is a duality between `any` and `union`
+ // An `any` has a pointer to the data and allows for any type (open)
+ // A `union` has as binary blob to store the data and allows only certain types (closed)
+ // The following code is with `any` but has the same syntax
+ val: any
+ val = 137
+ if i, ok := val.(int); ok {
+ fmt.println(i)
+ }
+ val = true
+ fmt.println(val)
+
+ val = nil
+
+ switch v in val {
+ case int: fmt.println("int", v)
+ case bool: fmt.println("bool", v)
+ case: fmt.println("nil")
+ }
+ }
+
+ Vector3 :: distinct [3]f32
+ Quaternion :: distinct quaternion128
+
+ // More realistic examples
+ {
+ // NOTE(bill): For the above basic examples, you may not have any
+ // particular use for it. However, my main use for them is not for these
+ // simple cases. My main use is for hierarchical types. Many prefer
+ // subtyping, embedding the base data into the derived types. Below is
+ // an example of this for a basic game Entity.
+
+ Entity :: struct {
+ id: u64,
+ name: string,
+ position: Vector3,
+ orientation: Quaternion,
+
+ derived: any,
+ }
+
+ Frog :: struct {
+ using entity: Entity,
+ jump_height: f32,
+ }
+
+ Monster :: struct {
+ using entity: Entity,
+ is_robot: bool,
+ is_zombie: bool,
+ }
+
+ // See `parametric_polymorphism` procedure for details
+ new_entity :: proc($T: typeid) -> ^Entity {
+ t := new(T)
+ t.derived = t^
+ return t
+ }
+
+ entity := new_entity(Monster)
+
+ switch e in entity.derived {
+ case Frog:
+ fmt.println("Ribbit")
+ case Monster:
+ if e.is_robot { fmt.println("Robotic") }
+ if e.is_zombie { fmt.println("Grrrr!") }
+ fmt.println("I'm a monster")
+ }
+ }
+
+ {
+ // NOTE(bill): A union can be used to achieve something similar. Instead
+ // of embedding the base data into the derived types, the derived data
+ // in embedded into the base type. Below is the same example of the
+ // basic game Entity but using an union.
+
+ Entity :: struct {
+ id: u64,
+ name: string,
+ position: Vector3,
+ orientation: Quaternion,
+
+ derived: union {Frog, Monster},
+ }
+
+ Frog :: struct {
+ using entity: ^Entity,
+ jump_height: f32,
+ }
+
+ Monster :: struct {
+ using entity: ^Entity,
+ is_robot: bool,
+ is_zombie: bool,
+ }
+
+ // See `parametric_polymorphism` procedure for details
+ new_entity :: proc($T: typeid) -> ^Entity {
+ t := new(Entity)
+ t.derived = T{entity = t}
+ return t
+ }
+
+ entity := new_entity(Monster)
+
+ switch e in entity.derived {
+ case Frog:
+ fmt.println("Ribbit")
+ case Monster:
+ if e.is_robot { fmt.println("Robotic") }
+ if e.is_zombie { fmt.println("Grrrr!") }
+ }
+
+ // NOTE(bill): As you can see, the usage code has not changed, only its
+ // memory layout. Both approaches have their own advantages but they can
+ // be used together to achieve different results. The subtyping approach
+ // can allow for a greater control of the memory layout and memory
+ // allocation, e.g. storing the derivatives together. However, this is
+ // also its disadvantage. You must either preallocate arrays for each
+ // derivative separation (which can be easily missed) or preallocate a
+ // bunch of "raw" memory; determining the maximum size of the derived
+ // types would require the aid of metaprogramming. Unions solve this
+ // particular problem as the data is stored with the base data.
+ // Therefore, it is possible to preallocate, e.g. [100]Entity.
+
+ // It should be noted that the union approach can have the same memory
+ // layout as the any and with the same type restrictions by using a
+ // pointer type for the derivatives.
+
+ /*
+ Entity :: struct {
+ ...
+ derived: union{^Frog, ^Monster},
+ }
+
+ Frog :: struct {
+ using entity: Entity,
+ ...
+ }
+ Monster :: struct {
+ using entity: Entity,
+ ...
+
+ }
+ new_entity :: proc(T: type) -> ^Entity {
+ t := new(T)
+ t.derived = t
+ return t
+ }
+ */
+ }
+}
+
+using_statement :: proc() {
+ // IMPORTANT NOTE: `using` as a statement is an opt-in feature which can be abled
+ // by adding `#+feature using-stmt` to be beginning of the file
+ //
+ // `using` as a struct field modifier remains available always
+
+ fmt.println("\n# using statement")
+ // using can used to bring entities declared in a scope/namespace
+ // into the current scope. This can be applied to import names, struct
+ // fields, procedure fields, and struct values.
+
+ Vector3 :: struct{x, y, z: f32}
+ {
+ Entity :: struct {
+ position: Vector3,
+ orientation: quaternion128,
+ }
+
+ // It can used like this:
+ foo0 :: proc(entity: ^Entity) {
+ fmt.println(entity.position.x, entity.position.y, entity.position.z)
+ }
+
+ // The entity members can be brought into the procedure scope by using it:
+ foo1 :: proc(entity: ^Entity) {
+ using entity
+ fmt.println(position.x, position.y, position.z)
+ }
+
+ // The using can be applied to the parameter directly:
+ foo2 :: proc(using entity: ^Entity) {
+ fmt.println(position.x, position.y, position.z)
+ }
+
+ // It can also be applied to sub-fields:
+ foo3 :: proc(entity: ^Entity) {
+ using entity.position
+ fmt.println(x, y, z)
+ }
+ }
+ {
+ // We can also apply the using statement to the struct fields directly,
+ // making all the fields of position appear as if they on Entity itself:
+ Entity :: struct {
+ using position: Vector3,
+ orientation: quaternion128,
+ }
+ foo :: proc(entity: ^Entity) {
+ fmt.println(entity.x, entity.y, entity.z)
+ }
+
+
+ // Subtype polymorphism
+ // It is possible to get subtype polymorphism, similar to inheritance-like
+ // functionality in C++, but without the requirement of vtables or unknown
+ // struct layout:
+
+ Colour :: struct {r, g, b, a: u8}
+ Frog :: struct {
+ ribbit_volume: f32,
+ using entity: Entity,
+ colour: Colour,
+ }
+
+ frog: Frog
+ // Both work
+ foo(&frog.entity)
+ foo(&frog)
+ frog.x = 123
+
+ // Note: using can be applied to arbitrarily many things, which allows
+ // the ability to have multiple subtype polymorphism (but also its issues).
+
+ // Note: using’d fields can still be referred by name.
+ }
+}
+
+
+implicit_context_system :: proc() {
+ fmt.println("\n# implicit context system")
+ // In each scope, there is an implicit value named context. This
+ // context variable is local to each scope and is implicitly passed
+ // by pointer to any procedure call in that scope (if the procedure
+ // has the Odin calling convention).
+
+ // The main purpose of the implicit context system is for the ability
+ // to intercept third-party code and libraries and modify their
+ // functionality. One such case is modifying how a library allocates
+ // something or logs something. In C, this was usually achieved with
+ // the library defining macros which could be overridden so that the
+ // user could define what he wanted. However, not many libraries
+ // supported this in many languages by default which meant intercepting
+ // third-party code to see what it does and to change how it does it is
+ // not possible.
+
+ c := context // copy the current scope's context
+
+ context.user_index = 456
+ {
+ context.allocator = my_custom_allocator()
+ context.user_index = 123
+ what_a_fool_believes() // the `context` for this scope is implicitly passed to `what_a_fool_believes`
+ }
+
+ // `context` value is local to the scope it is in
+ assert(context.user_index == 456)
+
+ what_a_fool_believes :: proc() {
+ c := context // this `context` is the same as the parent procedure that it was called from
+ // From this example, context.user_index == 123
+ // A context.allocator is assigned to the return value of `my_custom_allocator()`
+ assert(context.user_index == 123)
+
+ // The memory management procedure use the `context.allocator` by
+ // default unless explicitly specified otherwise
+ china_grove := new(int)
+ free(china_grove)
+
+ _ = c
+ }
+
+ my_custom_allocator :: mem.nil_allocator
+ _ = c
+
+ // By default, the context value has default values for its parameters which is
+ // decided in the package runtime. What the defaults are are compiler specific.
+
+ // To see what the implicit context value contains, please see the following
+ // definition in package runtime.
+}
+
+parametric_polymorphism :: proc() {
+ fmt.println("\n# parametric polymorphism")
+
+ print_value :: proc(value: $T) {
+ fmt.printf("print_value: %T %v\n", value, value)
+ }
+
+ v1: int = 1
+ v2: f32 = 2.1
+ v3: f64 = 3.14
+ v4: string = "message"
+
+ print_value(v1)
+ print_value(v2)
+ print_value(v3)
+ print_value(v4)
+
+ fmt.println()
+
+ add :: proc(p, q: $T) -> T {
+ x: T = p + q
+ return x
+ }
+
+ a := add(3, 4)
+ fmt.printf("a: %T = %v\n", a, a)
+
+ b := add(3.2, 4.3)
+ fmt.printf("b: %T = %v\n", b, b)
+
+ // This is how `new` is implemented
+ alloc_type :: proc($T: typeid) -> ^T {
+ t := cast(^T)mem.alloc(size_of(T), align_of(T))
+ t^ = T{} // Use default initialization value
+ return t
+ }
+
+ copy_slice :: proc(dst, src: []$T) -> int {
+ n := min(len(dst), len(src))
+ if n > 0 {
+ mem.copy(&dst[0], &src[0], n*size_of(T))
+ }
+ return n
+ }
+
+ double_params :: proc(a: $A, b: $B) -> A {
+ return a + A(b)
+ }
+
+ fmt.println(double_params(12, 1.345))
+
+
+
+ { // Polymorphic Types and Type Specialization
+ Table_Slot :: struct($Key, $Value: typeid) {
+ occupied: bool,
+ hash: u32,
+ key: Key,
+ value: Value,
+ }
+ TABLE_SIZE_MIN :: 32
+ Table :: struct($Key, $Value: typeid) {
+ count: int,
+ allocator: mem.Allocator,
+ slots: []Table_Slot(Key, Value),
+ }
+
+ // Only allow types that are specializations of a (polymorphic) slice
+ make_slice :: proc($T: typeid/[]$E, len: int) -> T {
+ return make(T, len)
+ }
+
+ // Only allow types that are specializations of `Table`
+ allocate :: proc(table: ^$T/Table, capacity: int) {
+ c := context
+ if table.allocator.procedure != nil {
+ c.allocator = table.allocator
+ }
+ context = c
+
+ table.slots = make_slice(type_of(table.slots), max(capacity, TABLE_SIZE_MIN))
+ }
+
+ expand :: proc(table: ^$T/Table) {
+ c := context
+ if table.allocator.procedure != nil {
+ c.allocator = table.allocator
+ }
+ context = c
+
+ old_slots := table.slots
+ defer delete(old_slots)
+
+ cap := max(2*len(table.slots), TABLE_SIZE_MIN)
+ allocate(table, cap)
+
+ for s in old_slots {
+ if s.occupied {
+ put(table, s.key, s.value)
+ }
+ }
+ }
+
+ // Polymorphic determination of a polymorphic struct
+ // put :: proc(table: ^$T/Table, key: T.Key, value: T.Value) {
+ put :: proc(table: ^Table($Key, $Value), key: Key, value: Value) {
+ hash := get_hash(key) // Ad-hoc method which would fail in a different scope
+ index := find_index(table, key, hash)
+ if index < 0 {
+ if f64(table.count) >= 0.75*f64(len(table.slots)) {
+ expand(table)
+ }
+ assert(table.count <= len(table.slots))
+
+ index = int(hash % u32(len(table.slots)))
+
+ for table.slots[index].occupied {
+ if index += 1; index >= len(table.slots) {
+ index = 0
+ }
+ }
+
+ table.count += 1
+ }
+
+ slot := &table.slots[index]
+ slot.occupied = true
+ slot.hash = hash
+ slot.key = key
+ slot.value = value
+ }
+
+
+ // find :: proc(table: ^$T/Table, key: T.Key) -> (T.Value, bool) {
+ find :: proc(table: ^Table($Key, $Value), key: Key) -> (Value, bool) {
+ hash := get_hash(key)
+ index := find_index(table, key, hash)
+ if index < 0 {
+ return Value{}, false
+ }
+ return table.slots[index].value, true
+ }
+
+ find_index :: proc(table: ^Table($Key, $Value), key: Key, hash: u32) -> int {
+ if len(table.slots) <= 0 {
+ return -1
+ }
+
+ index := int(hash % u32(len(table.slots)))
+ for table.slots[index].occupied {
+ if table.slots[index].hash == hash {
+ if table.slots[index].key == key {
+ return index
+ }
+ }
+
+ if index += 1; index >= len(table.slots) {
+ index = 0
+ }
+ }
+
+ return -1
+ }
+
+ get_hash :: proc(s: string) -> u32 { // fnv32a
+ h: u32 = 0x811c9dc5
+ for i in 0..<len(s) {
+ h = (h ~ u32(s[i])) * 0x01000193
+ }
+ return h
+ }
+
+
+ table: Table(string, int)
+
+ for i in 0..=36 { put(&table, "Hellope", i) }
+ for i in 0..=42 { put(&table, "World!", i) }
+
+ found, _ := find(&table, "Hellope")
+ fmt.printf("`found` is %v\n", found)
+
+ found, _ = find(&table, "World!")
+ fmt.printf("`found` is %v\n", found)
+
+ // I would not personally design a hash table like this in production
+ // but this is a nice basic example
+ // A better approach would either use a `u64` or equivalent for the key
+ // and let the user specify the hashing function or make the user store
+ // the hashing procedure with the table
+ }
+
+ { // Parametric polymorphic union
+ Error :: enum {
+ Foo0,
+ Foo1,
+ Foo2,
+ Foo3,
+ }
+ Para_Union :: union($T: typeid) {T, Error}
+ r: Para_Union(int)
+ fmt.println(typeid_of(type_of(r)))
+
+ fmt.println(r)
+ r = 123
+ fmt.println(r)
+ r = Error.Foo0 // r = .Foo0 is allow too, see implicit selector expressions below
+ fmt.println(r)
+ }
+
+ { // Polymorphic names
+ foo :: proc($N: $I, $T: typeid) -> (res: [N]T) {
+ // `N` is the constant value passed
+ // `I` is the type of N
+ // `T` is the type passed
+ fmt.printf("Generating an array of type %v from the value %v of type %v\n",
+ typeid_of(type_of(res)), N, typeid_of(I))
+ for i in 0..<N {
+ res[i] = T(i*i)
+ }
+ return
+ }
+
+ T :: int
+ array := foo(4, T)
+ for v, i in array {
+ assert(v == T(i*i))
+ }
+
+ // Matrix multiplication
+ mul :: proc(a: [$M][$N]$T, b: [N][$P]T) -> (c: [M][P]T) {
+ for i in 0..<M {
+ for j in 0..<P {
+ for k in 0..<N {
+ c[i][j] += a[i][k] * b[k][j]
+ }
+ }
+ }
+ return
+ }
+
+ x := [2][3]f32{
+ {1, 2, 3},
+ {3, 2, 1},
+ }
+ y := [3][2]f32{
+ {0, 8},
+ {6, 2},
+ {8, 4},
+ }
+ z := mul(x, y)
+ assert(z == {{36, 24}, {20, 32}})
+ }
+}
+
+
+prefix_table := [?]string{
+ "White",
+ "Red",
+ "Green",
+ "Blue",
+ "Octarine",
+ "Black",
+}
+
+print_mutex := b64(false)
+
+@(disabled=!thread.IS_SUPPORTED)
+threading_example :: proc() {
+ fmt.println("\n# threading_example")
+
+ did_acquire :: proc(m: ^b64) -> (acquired: bool) {
+ res, ok := intrinsics.atomic_compare_exchange_strong(m, false, true)
+ return ok && res == false
+ }
+
+ { // Basic Threads
+ fmt.println("\n## Basic Threads")
+ worker_proc :: proc(t: ^thread.Thread) {
+ for iteration in 1..=5 {
+ fmt.printf("Thread %d is on iteration %d\n", t.user_index, iteration)
+ fmt.printf("`%s`: iteration %d\n", prefix_table[t.user_index], iteration)
+ time.sleep(1 * time.Millisecond)
+ }
+ }
+
+ threads := make([dynamic]^thread.Thread, 0, len(prefix_table))
+ defer delete(threads)
+
+ for _ in prefix_table {
+ if t := thread.create(worker_proc); t != nil {
+ t.init_context = context
+ t.user_index = len(threads)
+ append(&threads, t)
+ thread.start(t)
+ }
+ }
+
+ for len(threads) > 0 {
+ for i := 0; i < len(threads); /**/ {
+ if t := threads[i]; thread.is_done(t) {
+ fmt.printf("Thread %d is done\n", t.user_index)
+ thread.destroy(t)
+
+ ordered_remove(&threads, i)
+ } else {
+ i += 1
+ }
+ }
+ }
+ }
+
+ { // Thread Pool
+ fmt.println("\n## Thread Pool")
+ task_proc :: proc(t: thread.Task) {
+ index := t.user_index % len(prefix_table)
+ for iteration in 1..=5 {
+ for !did_acquire(&print_mutex) { thread.yield() } // Allow one thread to print at a time.
+
+ fmt.printf("Worker Task %d is on iteration %d\n", t.user_index, iteration)
+ fmt.printf("`%s`: iteration %d\n", prefix_table[index], iteration)
+
+ print_mutex = false
+
+ time.sleep(1 * time.Millisecond)
+ }
+ }
+
+ N :: 3
+
+ pool: thread.Pool
+ thread.pool_init(&pool, allocator=context.allocator, thread_count=N)
+ defer thread.pool_destroy(&pool)
+
+
+ for i in 0..<30 {
+ // be mindful of the allocator used for tasks. The allocator needs to be thread safe, or be owned by the task for exclusive use
+ thread.pool_add_task(&pool, allocator=context.allocator, procedure=task_proc, data=nil, user_index=i)
+ }
+
+ thread.pool_start(&pool)
+ thread.pool_finish(&pool)
+ }
+}
+
+
+array_programming :: proc() {
+ fmt.println("\n# array programming")
+ {
+ a := [3]f32{1, 2, 3}
+ b := [3]f32{5, 6, 7}
+ c := a * b
+ d := a + b
+ e := 1 + (c - d) / 2
+ fmt.printf("%.1f\n", e) // [0.5, 3.0, 6.5]
+ }
+
+ {
+ a := [3]f32{1, 2, 3}
+ b := swizzle(a, 2, 1, 0)
+ assert(b == [3]f32{3, 2, 1})
+
+ c := swizzle(a, 0, 0)
+ assert(c == [2]f32{1, 1})
+ assert(c == 1)
+ }
+
+ {
+ Vector3 :: distinct [3]f32
+ a := Vector3{1, 2, 3}
+ b := Vector3{5, 6, 7}
+ c := (a * b)/2 + 1
+ d := c.x + c.y + c.z
+ fmt.printf("%.1f\n", d) // 22.0
+
+ cross :: proc(a, b: Vector3) -> Vector3 {
+ i := swizzle(a, 1, 2, 0) * swizzle(b, 2, 0, 1)
+ j := swizzle(a, 2, 0, 1) * swizzle(b, 1, 2, 0)
+ return i - j
+ }
+
+ cross_shorter :: proc(a, b: Vector3) -> Vector3 {
+ i := a.yzx * b.zxy
+ j := a.zxy * b.yzx
+ return i - j
+ }
+
+ blah :: proc(a: Vector3) -> f32 {
+ return a.x + a.y + a.z
+ }
+
+ x := cross(a, b)
+ fmt.println(x)
+ fmt.println(blah(x))
+ }
+}
+
+map_type :: proc() {
+ fmt.println("\n# map type")
+
+ m := make(map[string]int)
+ defer delete(m)
+
+ m["Bob"] = 2
+ m["Ted"] = 5
+ fmt.println(m["Bob"])
+
+ delete_key(&m, "Ted")
+
+ // If an element of a key does not exist, the zero value of the
+ // element will be returned. To check to see if an element exists
+ // can be done in two ways:
+ elem, ok := m["Bob"]
+ exists := "Bob" in m
+ _, _ = elem, ok
+ _ = exists
+}
+
+implicit_selector_expression :: proc() {
+ fmt.println("\n# implicit selector expression")
+
+ Foo :: enum {A, B, C}
+
+ f: Foo
+ f = Foo.A
+ f = .A
+
+ BAR :: bit_set[Foo]{.B, .C}
+
+ switch f {
+ case .A:
+ fmt.println("HITHER")
+ case .B:
+ fmt.println("NEVER")
+ case .C:
+ fmt.println("FOREVER")
+ }
+
+ my_map := make(map[Foo]int)
+ defer delete(my_map)
+
+ my_map[.A] = 123
+ my_map[Foo.B] = 345
+
+ fmt.println(my_map[.A] + my_map[Foo.B] + my_map[.C])
+}
+
+
+partial_switch :: proc() {
+ fmt.println("\n# partial_switch")
+ { // enum
+ Foo :: enum {
+ A,
+ B,
+ C,
+ D,
+ }
+
+ f := Foo.A
+ switch f {
+ case .A: fmt.println("A")
+ case .B: fmt.println("B")
+ case .C: fmt.println("C")
+ case .D: fmt.println("D")
+ case: fmt.println("?")
+ }
+
+ #partial switch f {
+ case .A: fmt.println("A")
+ case .D: fmt.println("D")
+ }
+ }
+ { // union
+ Foo :: union {int, bool}
+ f: Foo = 123
+ switch _ in f {
+ case int: fmt.println("int")
+ case bool: fmt.println("bool")
+ case:
+ }
+
+ #partial switch _ in f {
+ case bool: fmt.println("bool")
+ }
+ }
+}
+
+cstring_example :: proc() {
+ fmt.println("\n# cstring_example")
+
+ W :: "Hellope"
+ X :: cstring(W)
+ Y :: string(X)
+
+ w := W
+ _ = w
+ x: cstring = X
+ y: string = Y
+ z := string(x)
+ fmt.println(x, y, z)
+ fmt.println(len(x), len(y), len(z))
+ fmt.println(len(W), len(X), len(Y))
+ // IMPORTANT NOTE for cstring variables
+ // len(cstring) is O(N)
+ // cast(string)cstring is O(N)
+}
+
+bit_set_type :: proc() {
+ fmt.println("\n# bit_set type")
+
+ {
+ Day :: enum {
+ Sunday,
+ Monday,
+ Tuesday,
+ Wednesday,
+ Thursday,
+ Friday,
+ Saturday,
+ }
+
+ Days :: distinct bit_set[Day]
+ WEEKEND :: Days{.Sunday, .Saturday}
+
+ d: Days
+ d = {.Sunday, .Monday}
+ e := d + WEEKEND
+ e += {.Monday}
+ fmt.println(d, e)
+
+ ok := .Saturday in e // `in` is only allowed for `map` and `bit_set` types
+ fmt.println(ok)
+ if .Saturday in e {
+ fmt.println("Saturday in", e)
+ }
+ X :: .Saturday in WEEKEND // Constant evaluation
+ fmt.println(X)
+ fmt.println("Cardinality:", card(e))
+ }
+ {
+ x: bit_set['A'..='Z']
+ #assert(size_of(x) == size_of(u32))
+ y: bit_set[0..=8; u16]
+ fmt.println(typeid_of(type_of(x))) // bit_set[A..=Z]
+ fmt.println(typeid_of(type_of(y))) // bit_set[0..=8; u16]
+
+ x += {'F'}
+ assert('F' in x)
+ x -= {'F'}
+ assert('F' not_in x)
+
+ y += {1, 4, 2}
+ assert(2 in y)
+ }
+ {
+ Letters :: bit_set['A'..='Z']
+ a := Letters{'A', 'B'}
+ b := Letters{'A', 'B', 'C', 'D', 'F'}
+ c := Letters{'A', 'B'}
+
+ assert(a <= b) // 'a' is a subset of 'b'
+ assert(b >= a) // 'b' is a superset of 'a'
+ assert(a < b) // 'a' is a strict subset of 'b'
+ assert(b > a) // 'b' is a strict superset of 'a'
+
+ assert(!(a < c)) // 'a' is a not strict subset of 'c'
+ assert(!(c > a)) // 'c' is a not strict superset of 'a'
+ }
+}
+
+deferred_procedure_associations :: proc() {
+ fmt.println("\n# deferred procedure associations")
+
+ @(deferred_out=closure)
+ open :: proc(s: string) -> bool {
+ fmt.println(s)
+ return true
+ }
+
+ closure :: proc(ok: bool) {
+ fmt.println("Goodbye?", ok)
+ }
+
+ if open("Welcome") {
+ fmt.println("Something in the middle, mate.")
+ }
+}
+
+reflection :: proc() {
+ fmt.println("\n# reflection")
+
+ Foo :: struct {
+ x: int `tag1`,
+ y: string `json:"y_field"`,
+ z: bool, // no tag
+ }
+
+ id := typeid_of(Foo)
+ names := reflect.struct_field_names(id)
+ types := reflect.struct_field_types(id)
+ tags := reflect.struct_field_tags(id)
+
+ assert(len(names) == len(types) && len(names) == len(tags))
+
+ fmt.println("Foo :: struct {")
+ for tag, i in tags {
+ name, type := names[i], types[i]
+ if tag != "" {
+ fmt.printf("\t%s: %T `%s`,\n", name, type, tag)
+ } else {
+ fmt.printf("\t%s: %T,\n", name, type)
+ }
+ }
+ fmt.println("}")
+
+
+ for tag, i in tags {
+ if val, ok := reflect.struct_tag_lookup(tag, "json"); ok {
+ fmt.printf("json: %s -> %s\n", names[i], val)
+ }
+ }
+}
+
+quaternions :: proc() {
+ // Not just an April Fool's Joke any more, but a fully working thing!
+ fmt.println("\n# quaternions")
+
+ { // Quaternion operations
+ q := 1 + 2i + 3j + 4k
+ r := quaternion(real=5, imag=6, jmag=7, kmag=8)
+ t := q * r
+ fmt.printf("(%v) * (%v) = %v\n", q, r, t)
+ v := q / r
+ fmt.printf("(%v) / (%v) = %v\n", q, r, v)
+ u := q + r
+ fmt.printf("(%v) + (%v) = %v\n", q, r, u)
+ s := q - r
+ fmt.printf("(%v) - (%v) = %v\n", q, r, s)
+ }
+ { // The quaternion types
+ q128: quaternion128 // 4xf32
+ q256: quaternion256 // 4xf64
+ q128 = quaternion(w=1, x=0, y=0, z=0)
+ q256 = 1 // quaternion(x=0, y=0, z=0, w=1)
+
+ // NOTE: The internal memory layout of a quaternion is xyzw
+ }
+ { // Built-in procedures
+ q := 1 + 2i + 3j + 4k
+ fmt.println("q =", q)
+ fmt.println("real(q) =", real(q))
+ fmt.println("imag(q) =", imag(q))
+ fmt.println("jmag(q) =", jmag(q))
+ fmt.println("kmag(q) =", kmag(q))
+ fmt.println("conj(q) =", conj(q))
+ fmt.println("abs(q) =", abs(q))
+ }
+ { // Conversion of a complex type to a quaternion type
+ c := 1 + 2i
+ q := quaternion256(c)
+ fmt.println(c)
+ fmt.println(q)
+ }
+ { // Memory layout of Quaternions
+ q := 1 + 2i + 3j + 4k
+ a := transmute([4]f64)q
+ fmt.println("Quaternion memory layout: xyzw/(ijkr)")
+ fmt.println(q) // 1.000+2.000i+3.000j+4.000k
+ fmt.println(a) // [2.000, 3.000, 4.000, 1.000]
+ }
+}
+
+unroll_for_statement :: proc() {
+ fmt.println("\n#'#unroll for' statements")
+
+ // '#unroll for' works the same as if the 'inline' prefix did not
+ // exist but these ranged loops are explicitly unrolled which can
+ // be very very useful for certain optimizations
+
+ fmt.println("Ranges")
+ #unroll for x, i in 1..<4 {
+ fmt.println(x, i)
+ }
+
+ fmt.println("Strings")
+ #unroll for r, i in "Hello, 世界" {
+ fmt.println(r, i)
+ }
+
+ fmt.println("Arrays")
+ #unroll for elem, idx in ([4]int{1, 4, 9, 16}) {
+ fmt.println(elem, idx)
+ }
+
+
+ Foo_Enum :: enum {
+ A = 1,
+ B,
+ C = 6,
+ D,
+ }
+ fmt.println("Enum types")
+ #unroll for elem, idx in Foo_Enum {
+ fmt.println(elem, idx)
+ }
+}
+
+where_clauses :: proc() {
+ fmt.println("\n#procedure 'where' clauses")
+
+ { // Sanity checks
+ simple_sanity_check :: proc(x: [2]int)
+ where len(x) > 1,
+ type_of(x) == [2]int {
+ fmt.println(x)
+ }
+ }
+ { // Parametric polymorphism checks
+ cross_2d :: proc(a, b: $T/[2]$E) -> E
+ where intrinsics.type_is_numeric(E) {
+ return a.x*b.y - a.y*b.x
+ }
+ cross_3d :: proc(a, b: $T/[3]$E) -> T
+ where intrinsics.type_is_numeric(E) {
+ x := a.y*b.z - a.z*b.y
+ y := a.z*b.x - a.x*b.z
+ z := a.x*b.y - a.y*b.x
+ return T{x, y, z}
+ }
+
+ a := [2]int{1, 2}
+ b := [2]int{5, -3}
+ fmt.println(cross_2d(a, b))
+
+ x := [3]f32{1, 4, 9}
+ y := [3]f32{-5, 0, 3}
+ fmt.println(cross_3d(x, y))
+
+ // Failure case
+ // i := [2]bool{true, false}
+ // j := [2]bool{false, true}
+ // fmt.println(cross_2d(i, j))
+
+ }
+
+ { // Procedure groups usage
+ foo :: proc(x: [$N]int) -> bool
+ where N > 2 {
+ fmt.println(#procedure, "was called with the parameter", x)
+ return true
+ }
+
+ bar :: proc(x: [$N]int) -> bool
+ where 0 < N,
+ N <= 2 {
+ fmt.println(#procedure, "was called with the parameter", x)
+ return false
+ }
+
+ baz :: proc{foo, bar}
+
+ x := [3]int{1, 2, 3}
+ y := [2]int{4, 9}
+ ok_x := baz(x)
+ ok_y := baz(y)
+ assert(ok_x == true)
+ assert(ok_y == false)
+ }
+
+ { // Record types
+ Foo :: struct($T: typeid, $N: int)
+ where intrinsics.type_is_integer(T),
+ N > 2 {
+ x: [N]T,
+ y: [N-2]T,
+ }
+
+ T :: i32
+ N :: 5
+ f: Foo(T, N)
+ #assert(size_of(f) == (N+N-2)*size_of(T))
+ }
+}
+
+
+when ODIN_OS == .Windows {
+ foreign import kernel32 "system:kernel32.lib"
+}
+
+foreign_system :: proc() {
+ fmt.println("\n#foreign system")
+ when ODIN_OS == .Windows {
+ // It is sometimes necessarily to interface with foreign code,
+ // such as a C library. In Odin, this is achieved through the
+ // foreign system. You can “import” a library into the code
+ // using the same semantics as a normal import declaration.
+
+ // This foreign import declaration will create a
+ // “foreign import name” which can then be used to associate
+ // entities within a foreign block.
+
+ foreign kernel32 {
+ ExitProcess :: proc "stdcall" (exit_code: u32) ---
+ }
+
+ // Foreign procedure declarations have the cdecl/c calling
+ // convention by default unless specified otherwise. Due to
+ // foreign procedures do not have a body declared within this
+ // code, you need append the --- symbol to the end to distinguish
+ // it as a procedure literal without a body and not a procedure type.
+
+ // The attributes system can be used to change specific properties
+ // of entities declared within a block:
+
+ @(default_calling_convention = "std")
+ foreign kernel32 {
+ @(link_name="GetLastError") get_last_error :: proc() -> i32 ---
+ }
+
+ // Example using the link_prefix attribute
+ @(default_calling_convention = "std")
+ @(link_prefix = "Get")
+ foreign kernel32 {
+ LastError :: proc() -> i32 ---
+ }
+ }
+}
+
+ranged_fields_for_array_compound_literals :: proc() {
+ fmt.println("\n#ranged fields for array compound literals")
+ { // Normal Array Literal
+ foo := [?]int{1, 4, 9, 16}
+ fmt.println(foo)
+ }
+ { // Indexed
+ foo := [?]int{
+ 3 = 16,
+ 1 = 4,
+ 2 = 9,
+ 0 = 1,
+ }
+ fmt.println(foo)
+ }
+ { // Ranges
+ i := 2
+ foo := [?]int {
+ 0 = 123,
+ 5..=9 = 54,
+ 10..<16 = i*3 + (i-1)*2,
+ }
+ #assert(len(foo) == 16)
+ fmt.println(foo) // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
+ }
+ { // Slice and Dynamic Array support
+ i := 2
+ foo_slice := []int {
+ 0 = 123,
+ 5..=9 = 54,
+ 10..<16 = i*3 + (i-1)*2,
+ }
+ assert(len(foo_slice) == 16)
+ fmt.println(foo_slice) // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
+
+ foo_dynamic_array := [dynamic]int {
+ 0 = 123,
+ 5..=9 = 54,
+ 10..<16 = i*3 + (i-1)*2,
+ }
+ assert(len(foo_dynamic_array) == 16)
+ fmt.println(foo_dynamic_array) // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
+ }
+}
+
+deprecated_attribute :: proc() {
+ @(deprecated="Use foo_v2 instead")
+ foo_v1 :: proc(x: int) {
+ fmt.println("foo_v1")
+ }
+ foo_v2 :: proc(x: int) {
+ fmt.println("foo_v2")
+ }
+
+ // NOTE: Uncomment to see the warning messages
+ // foo_v1(1)
+}
+
+range_statements_with_multiple_return_values :: proc() {
+ fmt.println("\n#range statements with multiple return values")
+ My_Iterator :: struct {
+ index: int,
+ data: []i32,
+ }
+ make_my_iterator :: proc(data: []i32) -> My_Iterator {
+ return My_Iterator{data = data}
+ }
+ my_iterator :: proc(it: ^My_Iterator) -> (val: i32, idx: int, cond: bool) {
+ if cond = it.index < len(it.data); cond {
+ val = it.data[it.index]
+ idx = it.index
+ it.index += 1
+ }
+ return
+ }
+
+ data := make([]i32, 6)
+ for _, i in data {
+ data[i] = i32(i*i)
+ }
+
+ { // Manual Style
+ it := make_my_iterator(data)
+ for {
+ val, _, cond := my_iterator(&it)
+ if !cond {
+ break
+ }
+ fmt.println(val)
+ }
+ }
+ { // or_break
+ it := make_my_iterator(data)
+ loop: for {
+ val, _ := my_iterator(&it) or_break loop
+ fmt.println(val)
+ }
+ }
+ { // first value
+ it := make_my_iterator(data)
+ for val in my_iterator(&it) {
+ fmt.println(val)
+ }
+ }
+ { // first and second value
+ it := make_my_iterator(data)
+ for val, idx in my_iterator(&it) {
+ fmt.println(val, idx)
+ }
+ }
+}
+
+
+soa_struct_layout :: proc() {
+ fmt.println("\n#SOA Struct Layout")
+
+ {
+ Vector3 :: struct {x, y, z: f32}
+
+ N :: 2
+ v_aos: [N]Vector3
+ v_aos[0].x = 1
+ v_aos[0].y = 4
+ v_aos[0].z = 9
+
+ fmt.println(len(v_aos))
+ fmt.println(v_aos[0])
+ fmt.println(v_aos[0].x)
+ fmt.println(&v_aos[0].x)
+
+ v_aos[1] = {0, 3, 4}
+ v_aos[1].x = 2
+ fmt.println(v_aos[1])
+ fmt.println(v_aos)
+
+ v_soa: #soa[N]Vector3
+
+ v_soa[0].x = 1
+ v_soa[0].y = 4
+ v_soa[0].z = 9
+
+
+ // Same syntax as AOS and treat as if it was an array
+ fmt.println(len(v_soa))
+ fmt.println(v_soa[0])
+ fmt.println(v_soa[0].x)
+ fmt.println(&v_soa[0].x)
+ v_soa[1] = {0, 3, 4}
+ v_soa[1].x = 2
+ fmt.println(v_soa[1])
+
+ // Can use SOA syntax if necessary
+ v_soa.x[0] = 1
+ v_soa.y[0] = 4
+ v_soa.z[0] = 9
+ fmt.println(v_soa.x[0])
+
+ // Same pointer addresses with both syntaxes
+ assert(&v_soa[0].x == &v_soa.x[0])
+
+
+ // Same fmt printing
+ fmt.println(v_aos)
+ fmt.println(v_soa)
+ }
+ {
+ // Works with arrays of length <= 4 which have the implicit fields xyzw/rgba
+ Vector3 :: distinct [3]f32
+
+ N :: 2
+ v_aos: [N]Vector3
+ v_aos[0].x = 1
+ v_aos[0].y = 4
+ v_aos[0].z = 9
+
+ v_soa: #soa[N]Vector3
+
+ v_soa[0].x = 1
+ v_soa[0].y = 4
+ v_soa[0].z = 9
+ }
+ {
+ // SOA Slices
+ // Vector3 :: struct {x, y, z: f32}
+ Vector3 :: struct {x: i8, y: i16, z: f32}
+
+ N :: 3
+ v: #soa[N]Vector3
+ v[0].x = 1
+ v[0].y = 4
+ v[0].z = 9
+
+ s: #soa[]Vector3
+ s = v[:]
+ assert(len(s) == N)
+ fmt.println(s)
+ fmt.println(s[0].x)
+
+ a := s[1:2]
+ assert(len(a) == 1)
+ fmt.println(a)
+
+ d: #soa[dynamic]Vector3
+
+ append_soa(&d, Vector3{1, 2, 3}, Vector3{4, 5, 9}, Vector3{-4, -4, 3})
+ fmt.println(d)
+ fmt.println(len(d))
+ fmt.println(cap(d))
+ fmt.println(d[:])
+ }
+ { // soa_zip and soa_unzip
+ fmt.println("\nsoa_zip and soa_unzip")
+
+ x := []i32{1, 3, 9}
+ y := []f32{2, 4, 16}
+ z := []b32{true, false, true}
+
+ // produce an #soa slice the normal slices passed
+ s := soa_zip(a=x, b=y, c=z)
+
+ // iterate over the #soa slice
+ for v, i in s {
+ fmt.println(v, i) // exactly the same as s[i]
+ // NOTE: 'v' is NOT a temporary value but has a specialized addressing mode
+ // which means that when accessing v.a etc, it does the correct transformation
+ // internally:
+ // s[i].a === s.a[i]
+ fmt.println(v.a, v.b, v.c)
+ }
+
+ // Recover the slices from the #soa slice
+ a, b, c := soa_unzip(s)
+ fmt.println(a, b, c)
+ }
+}
+
+constant_literal_expressions :: proc() {
+ fmt.println("\n#constant literal expressions")
+
+ Bar :: struct {x, y: f32}
+ Foo :: struct {a, b: int, using c: Bar}
+
+ FOO_CONST :: Foo{b = 2, a = 1, c = {3, 4}}
+
+
+ fmt.println(FOO_CONST.a)
+ fmt.println(FOO_CONST.b)
+ fmt.println(FOO_CONST.c)
+ fmt.println(FOO_CONST.c.x)
+ fmt.println(FOO_CONST.c.y)
+ fmt.println(FOO_CONST.x) // using works as expected
+ fmt.println(FOO_CONST.y)
+
+ fmt.println("-------")
+
+ ARRAY_CONST :: [3]int{1 = 4, 2 = 9, 0 = 1}
+
+ fmt.println(ARRAY_CONST[0])
+ fmt.println(ARRAY_CONST[1])
+ fmt.println(ARRAY_CONST[2])
+
+ fmt.println("-------")
+
+ FOO_ARRAY_DEFAULTS :: [3]Foo{{}, {}, {}}
+ fmt.println(FOO_ARRAY_DEFAULTS[2].x)
+
+ fmt.println("-------")
+
+ Baz :: enum{A=5, B, C, D}
+ ENUM_ARRAY_CONST :: [Baz]int{.A ..= .C = 1, .D = 16}
+
+ fmt.println(ENUM_ARRAY_CONST[.A])
+ fmt.println(ENUM_ARRAY_CONST[.B])
+ fmt.println(ENUM_ARRAY_CONST[.C])
+ fmt.println(ENUM_ARRAY_CONST[.D])
+
+ fmt.println("-------")
+
+ Sparse_Baz :: enum{A=5, B, C, D=16}
+ #assert(len(Sparse_Baz) < len(#sparse[Sparse_Baz]int))
+ SPARSE_ENUM_ARRAY_CONST :: #sparse[Sparse_Baz]int{.A ..= .C = 1, .D = 16}
+
+ fmt.println(SPARSE_ENUM_ARRAY_CONST[.A])
+ fmt.println(SPARSE_ENUM_ARRAY_CONST[.B])
+ fmt.println(SPARSE_ENUM_ARRAY_CONST[.C])
+ fmt.println(SPARSE_ENUM_ARRAY_CONST[.D])
+
+ fmt.println("-------")
+
+
+ STRING_CONST :: "Hellope!"
+
+ fmt.println(STRING_CONST[0])
+ fmt.println(STRING_CONST[2])
+ fmt.println(STRING_CONST[3])
+
+ fmt.println(STRING_CONST[0:5])
+ fmt.println(STRING_CONST[3:][:4])
+}
+
+union_maybe :: proc() {
+ fmt.println("\n#union based maybe")
+
+ // NOTE: This is already built-in, and this is just a reimplementation to explain the behaviour
+ Maybe :: union($T: typeid) {T}
+
+ i: Maybe(u8)
+ p: Maybe(^u8) // No tag is stored for pointers, nil is the sentinel value
+
+ // Tag size will be as small as needed for the number of variants
+ #assert(size_of(i) == size_of(u8) + size_of(u8))
+ // No need to store a tag here, the `nil` state is shared with the variant's `nil`
+ #assert(size_of(p) == size_of(^u8))
+
+ i = 123
+ x := i.?
+ y, y_ok := p.?
+ p = &x
+ z, z_ok := p.?
+
+ fmt.println(i, p)
+ fmt.println(x, &x)
+ fmt.println(y, y_ok)
+ fmt.println(z, z_ok)
+}
+
+dummy_procedure :: proc() {
+ fmt.println("dummy_procedure")
+}
+
+explicit_context_definition :: proc "c" () {
+ // Try commenting the following statement out below
+ context = runtime.default_context()
+
+ fmt.println("\n#explicit context definition")
+ dummy_procedure()
+}
+
+or_else_operator :: proc() {
+ fmt.println("\n#'or_else'")
+ {
+ m: map[string]int
+ i: int
+ ok: bool
+
+ if i, ok = m["hellope"]; !ok {
+ i = 123
+ }
+ // The above can be mapped to 'or_else'
+ i = m["hellope"] or_else 123
+
+ assert(i == 123)
+ }
+ {
+ // 'or_else' can be used with type assertions too, as they
+ // have optional ok semantics
+ v: union{int, f64}
+ i: int
+ i = v.(int) or_else 123
+ i = v.? or_else 123 // Type inference magic
+ assert(i == 123)
+
+ m: Maybe(int)
+ i = m.? or_else 456
+ assert(i == 456)
+ }
+}
+
+or_return_operator :: proc() {
+ fmt.println("\n#'or_return'")
+ // The concept of 'or_return' will work by popping off the end value in a multiple
+ // valued expression and checking whether it was not 'nil' or 'false', and if so,
+ // set the end return value to value if possible. If the procedure only has one
+ // return value, it will do a simple return. If the procedure had multiple return
+ // values, 'or_return' will require that all parameters be named so that the end
+ // value could be assigned to by name and then an empty return could be called.
+
+ Error :: enum {
+ None,
+ Something_Bad,
+ Something_Worse,
+ The_Worst,
+ Your_Mum,
+ }
+
+ caller_1 :: proc() -> Error {
+ return .None
+ }
+
+ caller_2 :: proc() -> (int, Error) {
+ return 123, .None
+ }
+ caller_3 :: proc() -> (int, int, Error) {
+ return 123, 345, .None
+ }
+
+ foo_1 :: proc() -> Error {
+ // This can be a common idiom in many code bases
+ n0, err := caller_2()
+ if err != nil {
+ return err
+ }
+
+ // The above idiom can be transformed into the following
+ n1 := caller_2() or_return
+
+
+ // And if the expression is 1-valued, it can be used like this
+ caller_1() or_return
+ // which is functionally equivalent to
+ if err1 := caller_1(); err1 != nil {
+ return err1
+ }
+
+ // Multiple return values still work with 'or_return' as it only
+ // pops off the end value in the multi-valued expression
+ n0, n1 = caller_3() or_return
+
+ return .None
+ }
+ foo_2 :: proc() -> (n: int, err: Error) {
+ // It is more common that your procedure returns multiple values
+ // If 'or_return' is used within a procedure multiple parameters (2+),
+ // then all the parameters must be named so that the remaining parameters
+ // so that a bare 'return' statement can be used
+
+ // This can be a common idiom in many code bases
+ x: int
+ x, err = caller_2()
+ if err != nil {
+ return
+ }
+
+ // The above idiom can be transformed into the following
+ y := caller_2() or_return
+ _ = y
+
+ // And if the expression is 1-valued, it can be used like this
+ caller_1() or_return
+
+ // which is functionally equivalent to
+ if err1 := caller_1(); err1 != nil {
+ err = err1
+ return
+ }
+
+ // If using a non-bare 'return' statement is required, setting the return values
+ // using the normal idiom is a better choice and clearer to read.
+ if z, zerr := caller_2(); zerr != nil {
+ return -345 * z, zerr
+ }
+
+ defer if err != nil {
+ fmt.println("Error in", #procedure, ":" , err)
+ }
+
+ n = 123
+ return
+ }
+
+ foo_1()
+ foo_2()
+}
+
+
+or_break_and_or_continue_operators :: proc() {
+ fmt.println("\n#'or_break' and 'or_continue'")
+ // The concept of 'or_break' and 'or_continue' is very similar to that of 'or_return'.
+ // The difference is that unlike 'or_return', the value does not get returned from
+ // the current procedure but rather discarded if it is 'false' or not 'nil', and then
+ // the specified branch (i.e. break or continue).
+ // The or branch expression can be labelled if a specific statement needs to be used.
+
+ Error :: enum {
+ None,
+ Something_Bad,
+ Something_Worse,
+ The_Worst,
+ Your_Mum,
+ }
+
+ caller_1 :: proc() -> Error {
+ return .Something_Bad
+ }
+
+ caller_2 :: proc() -> (int, Error) {
+ return 123, .Something_Worse
+ }
+ caller_3 :: proc() -> (int, int, Error) {
+ return 123, 345, .None
+ }
+
+ for { // common approach
+ err := caller_1()
+ if err != nil {
+ break
+ }
+ }
+ for { // or_break approach
+ caller_1() or_break
+ }
+
+ for { // or_break approach with multiple values
+ n := caller_2() or_break
+ _ = n
+ }
+
+ loop: for { // or_break approach with named label
+ n := caller_2() or_break loop
+ _ = n
+ }
+
+ for { // or_continue
+ x, y := caller_3() or_continue
+ _, _ = x, y
+
+ break
+ }
+
+ continue_loop: for { // or_continue with named label
+ x, y := caller_3() or_continue continue_loop
+ _, _ = x, y
+
+ break
+ }
+
+}
+
+arbitrary_precision_mathematics :: proc() {
+ fmt.println("\n# core:math/big")
+
+ print_bigint :: proc(name: string, a: ^big.Int, base := i8(10), print_name := true, newline := true, print_extra_info := true) {
+ big.assert_if_nil(a)
+
+ as, err := big.itoa(a, base)
+ defer delete(as)
+
+ cb := big.internal_count_bits(a)
+ if print_name {
+ fmt.print(name)
+ }
+ if err != nil {
+ fmt.printf(" (Error: %v) ", err)
+ }
+ fmt.printf(as)
+ if print_extra_info {
+ fmt.printf(" (base: %v, bits: %v, digits: %v)", base, cb, a.used)
+ }
+ if newline {
+ fmt.println()
+ }
+ }
+
+ a, b, c, d, e, f, res := &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}, &big.Int{}
+ defer big.destroy(a, b, c, d, e, f, res)
+
+ // Set the context RNG to something that does not require
+ // cryptographic entropy (not supported on all targets).
+ context.random_generator = rand.xoshiro256_random_generator()
+
+ // How many bits should the random prime be?
+ bits := 64
+ // Number of Rabin-Miller trials, -1 for automatic.
+ trials := -1
+
+ // Default prime generation flags
+ flags := big.Primality_Flags{}
+
+ err := big.internal_random_prime(a, bits, trials, flags)
+ if err != nil {
+ fmt.printf("Error %v while generating random prime.\n", err)
+ } else {
+ print_bigint("Random Prime A: ", a, 10)
+ fmt.printf("Random number iterations until prime found: %v\n", big.RANDOM_PRIME_ITERATIONS_USED)
+ }
+
+ // If we want to pack this Int into a buffer of u32, how many do we need?
+ count := big.internal_int_pack_count(a, u32)
+ buf := make([]u32, count)
+ defer delete(buf)
+
+ written: int
+ written, err = big.internal_int_pack(a, buf)
+ fmt.printf("\nPacked into u32 buf: %v | err: %v | written: %v\n", buf, err, written)
+
+ // If we want to pack this Int into a buffer of bytes of which only the bottom 6 bits are used, how many do we need?
+ nails := 2
+
+ count = big.internal_int_pack_count(a, u8, nails)
+ byte_buf := make([]u8, count)
+ defer delete(byte_buf)
+
+ written, err = big.internal_int_pack(a, byte_buf, nails)
+ fmt.printf("\nPacked into buf of 6-bit bytes: %v | err: %v | written: %v\n", byte_buf, err, written)
+
+
+
+ // Pick another random big Int, not necesssarily prime.
+ err = big.random(b, 2048)
+ print_bigint("\n2048 bit random number: ", b)
+
+ // Calculate GCD + LCM in one fell swoop
+ big.gcd_lcm(c, d, a, b)
+
+ print_bigint("\nGCD of random prime A and random number B: ", c)
+ print_bigint("\nLCM of random prime A and random number B (in base 36): ", d, 36)
+}
+
+matrix_type :: proc() {
+ fmt.println("\n# matrix type")
+ // A matrix is a mathematical type built into Odin. It is a regular array of numbers,
+ // arranged in rows and columns
+
+ {
+ // The following represents a matrix that has 2 rows and 3 columns
+ m: matrix[2, 3]f32
+
+ m = matrix[2, 3]f32{
+ 1, 9, -13,
+ 20, 5, -6,
+ }
+
+ // Element types of integers, float, and complex numbers are supported by matrices.
+ // There is no support for booleans, quaternions, or any compound type.
+
+ // Indexing a matrix can be used with the matrix indexing syntax
+ // This mirrors other type usages: type on the left, usage on the right
+
+ elem := m[1, 2] // row 1, column 2
+ assert(elem == -6)
+
+
+ // Scalars act as if they are scaled identity matrices
+ // and can be assigned to matrices as them
+ b := matrix[2, 2]f32{}
+ f := f32(3)
+ b = f
+
+ fmt.println("b", b)
+ fmt.println("b == f", b == f)
+
+ }
+
+ { // Matrices support multiplication between matrices
+ a := matrix[2, 3]f32{
+ 2, 3, 1,
+ 4, 5, 0,
+ }
+
+ b := matrix[3, 2]f32{
+ 1, 2,
+ 3, 4,
+ 5, 6,
+ }
+
+ fmt.println("a", a)
+ fmt.println("b", b)
+
+ c := a * b
+ #assert(type_of(c) == matrix[2, 2]f32)
+ fmt.println("c = a * b", c)
+ }
+
+ { // Matrices support multiplication between matrices and arrays
+ m := matrix[4, 4]f32{
+ 1, 2, 3, 4,
+ 5, 5, 4, 2,
+ 0, 1, 3, 0,
+ 0, 1, 4, 1,
+ }
+
+ v := [4]f32{1, 5, 4, 3}
+
+ // treating 'v' as a column vector
+ fmt.println("m * v", m * v)
+
+ // treating 'v' as a row vector
+ fmt.println("v * m", v * m)
+
+ // Support with non-square matrices
+ s := matrix[2, 4]f32{ // [4][2]f32
+ 2, 4, 3, 1,
+ 7, 8, 6, 5,
+ }
+
+ w := [2]f32{1, 2}
+ r: [4]f32 = w * s
+ fmt.println("r", r)
+ }
+
+ { // Component-wise operations
+ // if the element type supports it
+ // Not support for '/', '%', or '%%' operations
+
+ a := matrix[2, 2]i32{
+ 1, 2,
+ 3, 4,
+ }
+
+ b := matrix[2, 2]i32{
+ -5, 1,
+ 9, -7,
+ }
+
+ c0 := a + b
+ c1 := a - b
+ c2 := a & b
+ c3 := a | b
+ c4 := a ~ b
+ c5 := a &~ b
+
+ // component-wise multiplication
+ // since a * b would be a standard matrix multiplication
+ c6 := intrinsics.hadamard_product(a, b)
+
+
+ fmt.println("a + b", c0)
+ fmt.println("a - b", c1)
+ fmt.println("a & b", c2)
+ fmt.println("a | b", c3)
+ fmt.println("a ~ b", c4)
+ fmt.println("a &~ b", c5)
+ fmt.println("hadamard_product(a, b)", c6)
+ }
+
+ { // Submatrix casting square matrices
+ // Casting a square matrix to another square matrix with same element type
+ // is supported.
+ // If the cast is to a smaller matrix type, the top-left submatrix is taken.
+ // If the cast is to a larger matrix type, the matrix is extended with zeros
+ // everywhere and ones in the diagonal for the unfilled elements of the
+ // extended matrix.
+
+ mat2 :: distinct matrix[2, 2]f32
+ mat4 :: distinct matrix[4, 4]f32
+
+ m2 := mat2{
+ 1, 3,
+ 2, 4,
+ }
+
+ m4 := mat4(m2)
+ assert(m4[2, 2] == 1)
+ assert(m4[3, 3] == 1)
+ fmt.printf("m2 %#v\n", m2)
+ fmt.println("m4", m4)
+ fmt.println("mat2(m4)", mat2(m4))
+ assert(mat2(m4) == m2)
+
+ b4 := mat4{
+ 1, 2, 0, 0,
+ 3, 4, 0, 0,
+ 5, 0, 6, 0,
+ 0, 7, 0, 8,
+ }
+ fmt.println("b4", intrinsics.matrix_flatten(b4))
+ }
+
+ { // Casting non-square matrices
+ // Casting a matrix to another matrix is allowed as long as they share
+ // the same element type and the number of elements (rows*columns).
+ // Matrices in Odin are stored in column-major order, which means
+ // the casts will preserve this element order.
+
+ mat2x4 :: distinct matrix[2, 4]f32
+ mat4x2 :: distinct matrix[4, 2]f32
+
+ x := mat2x4{
+ 1, 3, 5, 7,
+ 2, 4, 6, 8,
+ }
+
+ y := mat4x2(x)
+ fmt.println("x", x)
+ fmt.println("y", y)
+ }
+
+ // TECHNICAL INFORMATION: the internal representation of a matrix in Odin is stored
+ // in column-major format
+ // e.g. matrix[2, 3]f32 is internally [3][2]f32 (with different a alignment requirement)
+ // Column-major is used in order to utilize (SIMD) vector instructions effectively on
+ // modern hardware, if possible.
+ //
+ // Unlike normal arrays, matrices try to maximize alignment to allow for the (SIMD) vectorization
+ // properties whilst keeping zero padding (either between columns or at the end of the type).
+ //
+ // Zero padding is a compromise for use with third-party libraries, instead of optimizing for performance.
+ // Padding between columns was not taken even if that would have allowed each column to be loaded
+ // individually into a SIMD register with the correct alignment properties.
+ //
+ // Currently, matrices are limited to a maximum of 16 elements (rows*columns), and a minimum of 1 element.
+ // This is because matrices are stored as values (not a reference type), and thus operations on them will
+ // be stored on the stack. Restricting the maximum element count minimizing the possibility of stack overflows.
+
+ // 'intrinsics' Procedures (Compiler Level)
+ // transpose(m)
+ // transposes a matrix
+ // outer_product(a, b)
+ // takes two array-like data types and returns the outer product
+ // of the values in a matrix
+ // hadamard_product(a, b)
+ // component-wise multiplication of two matrices of the same type
+ // matrix_flatten(m)
+ // converts the matrix into a flatten array of elements
+ // in column-major order
+ // Example:
+ // m := matrix[2, 2]f32{
+ // x0, x1,
+ // y0, y1,
+ // }
+ // array: [4]f32 = matrix_flatten(m)
+ // assert(array == {x0, y0, x1, y1})
+ // conj(x)
+ // conjugates the elements of a matrix for complex element types only
+
+ // Procedures in "core:math/linalg" and related (Runtime Level) (all square matrix procedures)
+ // determinant(m)
+ // adjugate(m)
+ // inverse(m)
+ // inverse_transpose(m)
+ // hermitian_adjoint(m)
+ // trace(m)
+ // matrix_minor(m)
+}
+
+bit_field_type :: proc() {
+ fmt.println("\n# bit_field type")
+ // A `bit_field` is a record type in Odin that is akin to a bit-packed struct.
+ // IMPORTNAT NOTE: `bit_field` is NOT equivalent to `bit_set` as it has different sematics and use cases.
+
+ {
+ // `bit_field` fields are accessed by using a dot:
+ Foo :: bit_field u16 { // backing type must be an integer or array of integers
+ x: i32 | 3, // signed integers will be signed extended on use
+ y: u16 | 2 + 3, // general expressions
+ z: My_Enum | SOME_CONSTANT, // ability to define the bit-width elsewhere
+ w: bool | 2 when SOME_CONSTANT > 10 else 1,
+ }
+
+ v := Foo{}
+ v.x = 3 // truncates the value to fit into 3 bits
+ fmt.println(v.x) // accessing will convert `v.x` to an `i32` and do an appropriate sign extension
+
+
+ My_Enum :: enum u8 {A, B, C, D}
+ SOME_CONSTANT :: 7
+ }
+
+ {
+ // A `bit_field` is different from a struct in that you must specify the backing type.
+ // This backing type must be an integer or a fixed-length array of integers.
+ // This is useful if there needs to be a specific alignment or access pattern for the record.
+
+ Bar :: bit_field u32 {}
+ Baz :: bit_field [4]u8 {}
+ }
+
+ // IMPORTANT NOTES:
+ // * If _all_ of the fields in a bit_field are 1-bit in size and they are all booleans,
+ // please consider using a `bit_set` instead.
+ // * Odin's `bit_field` and C's bit-fields might not be compatible
+ // * Odin's `bit_field`s have a well defined layout (Least-Significant-Bit)
+ // * C's bit-fields on `struct`s are undefined and are not portable across targets and compilers
+ // * A `bit_field`'s field type can only be one of the following:
+ // * Integer
+ // * Boolean
+ // * Enum
+}
+
+main :: proc() {
+ /*
+ For More Odin Examples - https://github.com/odin-lang/examples
+ This repository contains examples of how certain things can be accomplished
+ in idiomatic Odin, allowing you learn its semantics, as well as how to use
+ parts of the core and vendor package collections.
+ */
+
+ when true {
+ the_basics()
+ control_flow()
+ named_proc_return_parameters()
+ variadic_procedures()
+ explicit_procedure_overloading()
+ struct_type()
+ union_type()
+ using_statement()
+ implicit_context_system()
+ parametric_polymorphism()
+ threading_example()
+ array_programming()
+ map_type()
+ implicit_selector_expression()
+ partial_switch()
+ cstring_example()
+ bit_set_type()
+ deferred_procedure_associations()
+ reflection()
+ quaternions()
+ unroll_for_statement()
+ where_clauses()
+ foreign_system()
+ ranged_fields_for_array_compound_literals()
+ deprecated_attribute()
+ range_statements_with_multiple_return_values()
+ soa_struct_layout()
+ constant_literal_expressions()
+ union_maybe()
+ explicit_context_definition()
+ or_else_operator()
+ or_return_operator()
+ or_break_and_or_continue_operators()
+ arbitrary_precision_mathematics()
+ matrix_type()
+ bit_field_type()
+ }
+}
+// END_INDENT
projects / thirdparty / vim.git / commitdiff
