demo.odin 45 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485148614871488148914901491149214931494149514961497149814991500150115021503150415051506150715081509151015111512151315141515151615171518151915201521152215231524152515261527152815291530153115321533153415351536153715381539154015411542154315441545154615471548154915501551155215531554155515561557155815591560156115621563156415651566156715681569157015711572157315741575157615771578157915801581158215831584158515861587158815891590159115921593159415951596159715981599160016011602160316041605160616071608160916101611161216131614161516161617161816191620162116221623162416251626162716281629163016311632163316341635163616371638163916401641164216431644164516461647164816491650165116521653165416551656165716581659166016611662166316641665166616671668166916701671167216731674167516761677167816791680168116821683168416851686168716881689169016911692169316941695169616971698169917001701170217031704170517061707170817091710171117121713171417151716171717181719172017211722172317241725172617271728172917301731173217331734173517361737173817391740174117421743174417451746174717481749175017511752175317541755175617571758175917601761176217631764176517661767176817691770177117721773177417751776177717781779178017811782178317841785178617871788178917901791179217931794179517961797179817991800180118021803180418051806180718081809181018111812181318141815181618171818181918201821182218231824182518261827182818291830183118321833183418351836183718381839184018411842184318441845184618471848184918501851185218531854185518561857185818591860186118621863186418651866186718681869187018711872187318741875187618771878187918801881188218831884188518861887188818891890189118921893189418951896189718981899190019011902190319041905190619071908190919101911191219131914191519161917191819191920192119221923192419251926192719281929193019311932193319341935193619371938193919401941194219431944194519461947194819491950195119521953195419551956195719581959196019611962196319641965196619671968196919701971197219731974197519761977197819791980198119821983198419851986198719881989199019911992199319941995199619971998199920002001200220032004200520062007
  1. package main
  2. import "core:fmt"
  3. import "core:mem"
  4. import "core:os"
  5. import "core:thread"
  6. import "core:time"
  7. import "core:reflect"
  8. import "core:runtime"
  9. import "intrinsics"
  10. /*
  11. The Odin programming language is fast, concise, readable, pragmatic and open sourced.
  12. It is designed with the intent of replacing C with the following goals:
  13. * simplicity
  14. * high performance
  15. * built for modern systems
  16. * joy of programming
  17. # Installing Odin
  18. Getting Started - https://odin-lang.org/docs/install/
  19. Instructions for downloading and install the Odin compiler and libraries.
  20. # Learning Odin
  21. Overview of Odin - https://odin-lang.org/docs/overview/
  22. An overview of the Odin programming language.
  23. Frequently Asked Questions (FAQ) - https://odin-lang.org/docs/faq/
  24. Answers to common questions about Odin.
  25. */
  26. the_basics :: proc() {
  27. fmt.println("\n# the basics")
  28. { // The Basics
  29. fmt.println("Hellope")
  30. // Lexical elements and literals
  31. // A comment
  32. my_integer_variable: int // A comment for documentaton
  33. // Multi-line comments begin with /* and end with */. Multi-line comments can
  34. // also be nested (unlike in C):
  35. /*
  36. You can have any text or code here and
  37. have it be commented.
  38. /*
  39. NOTE: comments can be nested!
  40. */
  41. */
  42. // String literals are enclosed in double quotes and character literals in single quotes.
  43. // Special characters are escaped with a backslash \
  44. some_string := "This is a string"
  45. _ = 'A' // unicode codepoint literal
  46. _ = '\n'
  47. _ = "C:\\Windows\\notepad.exe"
  48. // Raw string literals are enclosed with single back ticks
  49. _ = `C:\Windows\notepad.exe`
  50. // The length of a string in bytes can be found using the built-in `len` procedure:
  51. _ = len("Foo")
  52. _ = len(some_string)
  53. // Numbers
  54. // Numerical literals are written similar to most other programming languages.
  55. // A useful feature in Odin is that underscores are allowed for better
  56. // readability: 1_000_000_000 (one billion). A number that contains a dot is a
  57. // floating point literal: 1.0e9 (one billion). If a number literal is suffixed
  58. // with i, is an imaginary number literal: 2i (2 multiply the square root of -1).
  59. // Binary literals are prefixed with 0b, octal literals with 0o, and hexadecimal
  60. // literals 0x. A leading zero does not produce an octal constant (unlike C).
  61. // In Odin, if a number constant is possible to be represented by a type without
  62. // precision loss, it will automatically convert to that type.
  63. x: int = 1.0 // A float literal but it can be represented by an integer without precision loss
  64. // Constant literals are “untyped” which means that they can implicitly convert to a type.
  65. y: int // `y` is typed of type `int`
  66. y = 1 // `1` is an untyped integer literal which can implicitly convert to `int`
  67. z: f64 // `z` is typed of type `f64` (64-bit floating point number)
  68. z = 1 // `1` is an untyped integer literals which can be implicity conver to `f64`
  69. // No need for any suffixes or decimal places like in other languages
  70. // CONSTANTS JUST WORK!!!
  71. // Assignment statements
  72. h: int = 123 // declares a new variable `h` with type `int` and assigns a value to it
  73. h = 637 // assigns a new value to `h`
  74. // `=` is the assignment operator
  75. // You can assign multiple variables with it:
  76. a, b := 1, "hello" // declares `a` and `b` and infers the types from the assignments
  77. b, a = "byte", 0
  78. // Note: `:=` is two tokens, `:` and `=`. The following are equivalent,
  79. /*
  80. i: int = 123
  81. i: = 123
  82. i := 123
  83. */
  84. // Constant declarations
  85. // Constants are entities (symbols) which have an assigned value.
  86. // The constant’s value cannot be changed.
  87. // The constant’s value must be able to be evaluated at compile time:
  88. X :: "what" // constant `X` has the untyped string value "what"
  89. // Constants can be explicitly typed like a variable declaration:
  90. Y : int : 123
  91. Z :: Y + 7 // constant computations are possible
  92. _ = my_integer_variable
  93. _ = x
  94. }
  95. }
  96. control_flow :: proc() {
  97. fmt.println("\n# control flow")
  98. { // Control flow
  99. // For loop
  100. // Odin has only one loop statement, the `for` loop
  101. // Basic for loop
  102. for i := 0; i < 10; i += 1 {
  103. fmt.println(i)
  104. }
  105. // NOTE: Unlike other languages like C, there are no parentheses `( )` surrounding the three components.
  106. // Braces `{ }` or a `do` are always required
  107. for i := 0; i < 10; i += 1 { }
  108. // for i := 0; i < 10; i += 1 do fmt.print()
  109. // The initial and post statements are optional
  110. i := 0
  111. for ; i < 10; {
  112. i += 1
  113. }
  114. // These semicolons can be dropped. This `for` loop is equivalent to C's `while` loop
  115. i = 0
  116. for i < 10 {
  117. i += 1
  118. }
  119. // If the condition is omitted, this produces an infinite loop:
  120. for {
  121. break
  122. }
  123. // Range-based for loop
  124. // The basic for loop
  125. for j := 0; j < 10; j += 1 {
  126. fmt.println(j)
  127. }
  128. // can also be written
  129. for j in 0..<10 {
  130. fmt.println(j)
  131. }
  132. for j in 0..9 {
  133. fmt.println(j)
  134. }
  135. // Certain built-in types can be iterated over
  136. some_string := "Hello, 世界"
  137. for character in some_string { // Strings are assumed to be UTF-8
  138. fmt.println(character)
  139. }
  140. some_array := [3]int{1, 4, 9}
  141. for value in some_array {
  142. fmt.println(value)
  143. }
  144. some_slice := []int{1, 4, 9}
  145. for value in some_slice {
  146. fmt.println(value)
  147. }
  148. some_dynamic_array := [dynamic]int{1, 4, 9}
  149. defer delete(some_dynamic_array)
  150. for value in some_dynamic_array {
  151. fmt.println(value)
  152. }
  153. some_map := map[string]int{"A" = 1, "C" = 9, "B" = 4}
  154. defer delete(some_map)
  155. for key in some_map {
  156. fmt.println(key)
  157. }
  158. // Alternatively a second index value can be added
  159. for character, index in some_string {
  160. fmt.println(index, character)
  161. }
  162. for value, index in some_array {
  163. fmt.println(index, value)
  164. }
  165. for value, index in some_slice {
  166. fmt.println(index, value)
  167. }
  168. for value, index in some_dynamic_array {
  169. fmt.println(index, value)
  170. }
  171. for key, value in some_map {
  172. fmt.println(key, value)
  173. }
  174. // The iterated values are copies and cannot be written to.
  175. // The following idiom is useful for iterating over a container in a by-reference manner:
  176. for _, idx in some_slice {
  177. some_slice[idx] = (idx+1)*(idx+1)
  178. }
  179. // If statements
  180. x := 123
  181. if x >= 0 {
  182. fmt.println("x is positive")
  183. }
  184. if y := -34; y < 0 {
  185. fmt.println("y is negative")
  186. }
  187. if y := 123; y < 0 {
  188. fmt.println("y is negative")
  189. } else if y == 0 {
  190. fmt.println("y is zero")
  191. } else {
  192. fmt.println("y is positive")
  193. }
  194. // Switch statement
  195. // A switch statement is another way to write a sequence of if-else statements.
  196. // In Odin, the default case is denoted as a case without any expression.
  197. switch arch := ODIN_ARCH; arch {
  198. case "386":
  199. fmt.println("32-bit")
  200. case "amd64":
  201. fmt.println("64-bit")
  202. case: // default
  203. fmt.println("Unsupported architecture")
  204. }
  205. // Odin’s `switch` is like one in C or C++, except that Odin only runs the selected case.
  206. // This means that a `break` statement is not needed at the end of each case.
  207. // Another important difference is that the case values need not be integers nor constants.
  208. // To achieve a C-like fall through into the next case block, the keyword `fallthrough` can be used.
  209. one_angry_dwarf :: proc() -> int {
  210. fmt.println("one_angry_dwarf was called")
  211. return 1
  212. }
  213. switch j := 0; j {
  214. case 0:
  215. case one_angry_dwarf():
  216. }
  217. // A switch statement without a condition is the same as `switch true`.
  218. // This can be used to write a clean and long if-else chain and have the
  219. // ability to break if needed
  220. switch {
  221. case x < 0:
  222. fmt.println("x is negative")
  223. case x == 0:
  224. fmt.println("x is zero")
  225. case:
  226. fmt.println("x is positive")
  227. }
  228. // A `switch` statement can also use ranges like a range-based loop:
  229. switch c := 'j'; c {
  230. case 'A'..'Z', 'a'..'z', '0'..'9':
  231. fmt.println("c is alphanumeric")
  232. }
  233. switch x {
  234. case 0..<10:
  235. fmt.println("units")
  236. case 10..<13:
  237. fmt.println("pre-teens")
  238. case 13..<20:
  239. fmt.println("teens")
  240. case 20..<30:
  241. fmt.println("twenties")
  242. }
  243. }
  244. { // Defer statement
  245. // A defer statement defers the execution of a statement until the end of
  246. // the scope it is in.
  247. // The following will print 4 then 234:
  248. {
  249. x := 123
  250. defer fmt.println(x)
  251. {
  252. defer x = 4
  253. x = 2
  254. }
  255. fmt.println(x)
  256. x = 234
  257. }
  258. // You can defer an entire block too:
  259. {
  260. bar :: proc() {}
  261. defer {
  262. fmt.println("1")
  263. fmt.println("2")
  264. }
  265. cond := false
  266. defer if cond {
  267. bar()
  268. }
  269. }
  270. // Defer statements are executed in the reverse order that they were declared:
  271. {
  272. defer fmt.println("1")
  273. defer fmt.println("2")
  274. defer fmt.println("3")
  275. }
  276. // Will print 3, 2, and then 1.
  277. if false {
  278. f, err := os.open("my_file.txt")
  279. if err != 0 {
  280. // handle error
  281. }
  282. defer os.close(f)
  283. // rest of code
  284. }
  285. }
  286. { // When statement
  287. /*
  288. The when statement is almost identical to the if statement but with some differences:
  289. * Each condition must be a constant expression as a when
  290. statement is evaluated at compile time.
  291. * The statements within a branch do not create a new scope
  292. * The compiler checks the semantics and code only for statements
  293. that belong to the first condition that is true
  294. * An initial statement is not allowed in a when statement
  295. * when statements are allowed at file scope
  296. */
  297. // Example
  298. when ODIN_ARCH == "386" {
  299. fmt.println("32 bit")
  300. } else when ODIN_ARCH == "amd64" {
  301. fmt.println("64 bit")
  302. } else {
  303. fmt.println("Unsupported architecture")
  304. }
  305. // The when statement is very useful for writing platform specific code.
  306. // This is akin to the #if construct in C’s preprocessor however, in Odin,
  307. // it is type checked.
  308. }
  309. { // Branch statements
  310. cond, cond1, cond2 := false, false, false
  311. one_step :: proc() { fmt.println("one_step") }
  312. beyond :: proc() { fmt.println("beyond") }
  313. // Break statement
  314. for cond {
  315. switch {
  316. case:
  317. if cond {
  318. break // break out of the `switch` statement
  319. }
  320. }
  321. break // break out of the `for` statement
  322. }
  323. loop: for cond1 {
  324. for cond2 {
  325. break loop // leaves both loops
  326. }
  327. }
  328. // Continue statement
  329. for cond {
  330. if cond2 {
  331. continue
  332. }
  333. fmt.println("Hellope")
  334. }
  335. // Fallthrough statement
  336. // Odin’s switch is like one in C or C++, except that Odin only runs the selected
  337. // case. This means that a break statement is not needed at the end of each case.
  338. // Another important difference is that the case values need not be integers nor
  339. // constants.
  340. // fallthrough can be used to explicitly fall through into the next case block:
  341. switch i := 0; i {
  342. case 0:
  343. one_step()
  344. fallthrough
  345. case 1:
  346. beyond()
  347. }
  348. }
  349. }
  350. named_proc_return_parameters :: proc() {
  351. fmt.println("\n# named proc return parameters")
  352. foo0 :: proc() -> int {
  353. return 123
  354. }
  355. foo1 :: proc() -> (a: int) {
  356. a = 123
  357. return
  358. }
  359. foo2 :: proc() -> (a, b: int) {
  360. // Named return values act like variables within the scope
  361. a = 321
  362. b = 567
  363. return b, a
  364. }
  365. fmt.println("foo0 =", foo0()) // 123
  366. fmt.println("foo1 =", foo1()) // 123
  367. fmt.println("foo2 =", foo2()) // 567 321
  368. }
  369. explicit_procedure_overloading :: proc() {
  370. fmt.println("\n# explicit procedure overloading")
  371. add_ints :: proc(a, b: int) -> int {
  372. x := a + b
  373. fmt.println("add_ints", x)
  374. return x
  375. }
  376. add_floats :: proc(a, b: f32) -> f32 {
  377. x := a + b
  378. fmt.println("add_floats", x)
  379. return x
  380. }
  381. add_numbers :: proc(a: int, b: f32, c: u8) -> int {
  382. x := int(a) + int(b) + int(c)
  383. fmt.println("add_numbers", x)
  384. return x
  385. }
  386. add :: proc{add_ints, add_floats, add_numbers}
  387. add(int(1), int(2))
  388. add(f32(1), f32(2))
  389. add(int(1), f32(2), u8(3))
  390. add(1, 2) // untyped ints coerce to int tighter than f32
  391. add(1.0, 2.0) // untyped floats coerce to f32 tighter than int
  392. add(1, 2, 3) // three parameters
  393. // Ambiguous answers
  394. // add(1.0, 2)
  395. // add(1, 2.0)
  396. }
  397. struct_type :: proc() {
  398. fmt.println("\n# struct type")
  399. // A struct is a record type in Odin. It is a collection of fields.
  400. // Struct fields are accessed by using a dot:
  401. {
  402. Vector2 :: struct {
  403. x: f32,
  404. y: f32,
  405. }
  406. v := Vector2{1, 2}
  407. v.x = 4
  408. fmt.println(v.x)
  409. // Struct fields can be accessed through a struct pointer:
  410. v = Vector2{1, 2}
  411. p := &v
  412. p.x = 1335
  413. fmt.println(v)
  414. // We could write p^.x, however, it is to nice abstract the ability
  415. // to not explicitly dereference the pointer. This is very useful when
  416. // refactoring code to use a pointer rather than a value, and vice versa.
  417. }
  418. {
  419. // A struct literal can be denoted by providing the struct’s type
  420. // followed by {}. A struct literal must either provide all the
  421. // arguments or none:
  422. Vector3 :: struct {
  423. x, y, z: f32,
  424. }
  425. v: Vector3
  426. v = Vector3{} // Zero value
  427. v = Vector3{1, 4, 9}
  428. // You can list just a subset of the fields if you specify the
  429. // field by name (the order of the named fields does not matter):
  430. v = Vector3{z=1, y=2}
  431. assert(v.x == 0)
  432. assert(v.y == 2)
  433. assert(v.z == 1)
  434. }
  435. {
  436. // Structs can tagged with different memory layout and alignment requirements:
  437. a :: struct #align 4 {} // align to 4 bytes
  438. b :: struct #packed {} // remove padding between fields
  439. c :: struct #raw_union {} // all fields share the same offset (0). This is the same as C's union
  440. }
  441. }
  442. union_type :: proc() {
  443. fmt.println("\n# union type")
  444. {
  445. val: union{int, bool}
  446. val = 137
  447. if i, ok := val.(int); ok {
  448. fmt.println(i)
  449. }
  450. val = true
  451. fmt.println(val)
  452. val = nil
  453. switch v in val {
  454. case int: fmt.println("int", v)
  455. case bool: fmt.println("bool", v)
  456. case: fmt.println("nil")
  457. }
  458. }
  459. {
  460. // There is a duality between `any` and `union`
  461. // An `any` has a pointer to the data and allows for any type (open)
  462. // A `union` has as binary blob to store the data and allows only certain types (closed)
  463. // The following code is with `any` but has the same syntax
  464. val: any
  465. val = 137
  466. if i, ok := val.(int); ok {
  467. fmt.println(i)
  468. }
  469. val = true
  470. fmt.println(val)
  471. val = nil
  472. switch v in val {
  473. case int: fmt.println("int", v)
  474. case bool: fmt.println("bool", v)
  475. case: fmt.println("nil")
  476. }
  477. }
  478. Vector3 :: distinct [3]f32
  479. Quaternion :: distinct quaternion128
  480. // More realistic examples
  481. {
  482. // NOTE(bill): For the above basic examples, you may not have any
  483. // particular use for it. However, my main use for them is not for these
  484. // simple cases. My main use is for hierarchical types. Many prefer
  485. // subtyping, embedding the base data into the derived types. Below is
  486. // an example of this for a basic game Entity.
  487. Entity :: struct {
  488. id: u64,
  489. name: string,
  490. position: Vector3,
  491. orientation: Quaternion,
  492. derived: any,
  493. }
  494. Frog :: struct {
  495. using entity: Entity,
  496. jump_height: f32,
  497. }
  498. Monster :: struct {
  499. using entity: Entity,
  500. is_robot: bool,
  501. is_zombie: bool,
  502. }
  503. // See `parametric_polymorphism` procedure for details
  504. new_entity :: proc($T: typeid) -> ^Entity {
  505. t := new(T)
  506. t.derived = t^
  507. return t
  508. }
  509. entity := new_entity(Monster)
  510. switch e in entity.derived {
  511. case Frog:
  512. fmt.println("Ribbit")
  513. case Monster:
  514. if e.is_robot { fmt.println("Robotic") }
  515. if e.is_zombie { fmt.println("Grrrr!") }
  516. fmt.println("I'm a monster")
  517. }
  518. }
  519. {
  520. // NOTE(bill): A union can be used to achieve something similar. Instead
  521. // of embedding the base data into the derived types, the derived data
  522. // in embedded into the base type. Below is the same example of the
  523. // basic game Entity but using an union.
  524. Entity :: struct {
  525. id: u64,
  526. name: string,
  527. position: Vector3,
  528. orientation: Quaternion,
  529. derived: union {Frog, Monster},
  530. }
  531. Frog :: struct {
  532. using entity: ^Entity,
  533. jump_height: f32,
  534. }
  535. Monster :: struct {
  536. using entity: ^Entity,
  537. is_robot: bool,
  538. is_zombie: bool,
  539. }
  540. // See `parametric_polymorphism` procedure for details
  541. new_entity :: proc($T: typeid) -> ^Entity {
  542. t := new(Entity)
  543. t.derived = T{entity = t}
  544. return t
  545. }
  546. entity := new_entity(Monster)
  547. switch e in entity.derived {
  548. case Frog:
  549. fmt.println("Ribbit")
  550. case Monster:
  551. if e.is_robot { fmt.println("Robotic") }
  552. if e.is_zombie { fmt.println("Grrrr!") }
  553. }
  554. // NOTE(bill): As you can see, the usage code has not changed, only its
  555. // memory layout. Both approaches have their own advantages but they can
  556. // be used together to achieve different results. The subtyping approach
  557. // can allow for a greater control of the memory layout and memory
  558. // allocation, e.g. storing the derivatives together. However, this is
  559. // also its disadvantage. You must either preallocate arrays for each
  560. // derivative separation (which can be easily missed) or preallocate a
  561. // bunch of "raw" memory; determining the maximum size of the derived
  562. // types would require the aid of metaprogramming. Unions solve this
  563. // particular problem as the data is stored with the base data.
  564. // Therefore, it is possible to preallocate, e.g. [100]Entity.
  565. // It should be noted that the union approach can have the same memory
  566. // layout as the any and with the same type restrictions by using a
  567. // pointer type for the derivatives.
  568. /*
  569. Entity :: struct {
  570. ...
  571. derived: union{^Frog, ^Monster},
  572. }
  573. Frog :: struct {
  574. using entity: Entity,
  575. ...
  576. }
  577. Monster :: struct {
  578. using entity: Entity,
  579. ...
  580. }
  581. new_entity :: proc(T: type) -> ^Entity {
  582. t := new(T)
  583. t.derived = t
  584. return t
  585. }
  586. */
  587. }
  588. }
  589. using_statement :: proc() {
  590. fmt.println("\n# using statement")
  591. // using can used to bring entities declared in a scope/namespace
  592. // into the current scope. This can be applied to import names, struct
  593. // fields, procedure fields, and struct values.
  594. Vector3 :: struct{x, y, z: f32}
  595. {
  596. Entity :: struct {
  597. position: Vector3,
  598. orientation: quaternion128,
  599. }
  600. // It can used like this:
  601. foo0 :: proc(entity: ^Entity) {
  602. fmt.println(entity.position.x, entity.position.y, entity.position.z)
  603. }
  604. // The entity members can be brought into the procedure scope by using it:
  605. foo1 :: proc(entity: ^Entity) {
  606. using entity
  607. fmt.println(position.x, position.y, position.z)
  608. }
  609. // The using can be applied to the parameter directly:
  610. foo2 :: proc(using entity: ^Entity) {
  611. fmt.println(position.x, position.y, position.z)
  612. }
  613. // It can also be applied to sub-fields:
  614. foo3 :: proc(entity: ^Entity) {
  615. using entity.position
  616. fmt.println(x, y, z)
  617. }
  618. }
  619. {
  620. // We can also apply the using statement to the struct fields directly,
  621. // making all the fields of position appear as if they on Entity itself:
  622. Entity :: struct {
  623. using position: Vector3,
  624. orientation: quaternion128,
  625. }
  626. foo :: proc(entity: ^Entity) {
  627. fmt.println(entity.x, entity.y, entity.z)
  628. }
  629. // Subtype polymorphism
  630. // It is possible to get subtype polymorphism, similar to inheritance-like
  631. // functionality in C++, but without the requirement of vtables or unknown
  632. // struct layout:
  633. Colour :: struct {r, g, b, a: u8}
  634. Frog :: struct {
  635. ribbit_volume: f32,
  636. using entity: Entity,
  637. colour: Colour,
  638. }
  639. frog: Frog
  640. // Both work
  641. foo(&frog.entity)
  642. foo(&frog)
  643. frog.x = 123
  644. // Note: using can be applied to arbitrarily many things, which allows
  645. // the ability to have multiple subtype polymorphism (but also its issues).
  646. // Note: using’d fields can still be referred by name.
  647. }
  648. { // using on an enum declaration
  649. using Foo :: enum {A, B, C}
  650. f0 := A
  651. f1 := B
  652. f2 := C
  653. fmt.println(f0, f1, f2)
  654. fmt.println(len(Foo))
  655. }
  656. }
  657. implicit_context_system :: proc() {
  658. fmt.println("\n# implicit context system")
  659. // In each scope, there is an implicit value named context. This
  660. // context variable is local to each scope and is implicitly passed
  661. // by pointer to any procedure call in that scope (if the procedure
  662. // has the Odin calling convention).
  663. // The main purpose of the implicit context system is for the ability
  664. // to intercept third-party code and libraries and modify their
  665. // functionality. One such case is modifying how a library allocates
  666. // something or logs something. In C, this was usually achieved with
  667. // the library defining macros which could be overridden so that the
  668. // user could define what he wanted. However, not many libraries
  669. // supported this in many languages by default which meant intercepting
  670. // third-party code to see what it does and to change how it does it is
  671. // not possible.
  672. c := context // copy the current scope's context
  673. context.user_index = 456
  674. {
  675. context.allocator = my_custom_allocator()
  676. context.user_index = 123
  677. what_a_fool_believes() // the `context` for this scope is implicitly passed to `what_a_fool_believes`
  678. }
  679. // `context` value is local to the scope it is in
  680. assert(context.user_index == 456)
  681. what_a_fool_believes :: proc() {
  682. c := context // this `context` is the same as the parent procedure that it was called from
  683. // From this example, context.user_index == 123
  684. // An context.allocator is assigned to the return value of `my_custom_allocator()`
  685. assert(context.user_index == 123)
  686. // The memory management procedure use the `context.allocator` by
  687. // default unless explicitly specified otherwise
  688. china_grove := new(int)
  689. free(china_grove)
  690. _ = c
  691. }
  692. my_custom_allocator :: mem.nil_allocator
  693. _ = c
  694. // By default, the context value has default values for its parameters which is
  695. // decided in the package runtime. What the defaults are are compiler specific.
  696. // To see what the implicit context value contains, please see the following
  697. // definition in package runtime.
  698. }
  699. parametric_polymorphism :: proc() {
  700. fmt.println("\n# parametric polymorphism")
  701. print_value :: proc(value: $T) {
  702. fmt.printf("print_value: %T %v\n", value, value)
  703. }
  704. v1: int = 1
  705. v2: f32 = 2.1
  706. v3: f64 = 3.14
  707. v4: string = "message"
  708. print_value(v1)
  709. print_value(v2)
  710. print_value(v3)
  711. print_value(v4)
  712. fmt.println()
  713. add :: proc(p, q: $T) -> T {
  714. x: T = p + q
  715. return x
  716. }
  717. a := add(3, 4)
  718. fmt.printf("a: %T = %v\n", a, a)
  719. b := add(3.2, 4.3)
  720. fmt.printf("b: %T = %v\n", b, b)
  721. // This is how `new` is implemented
  722. alloc_type :: proc($T: typeid) -> ^T {
  723. t := cast(^T)alloc(size_of(T), align_of(T))
  724. t^ = T{} // Use default initialization value
  725. return t
  726. }
  727. copy_slice :: proc(dst, src: []$T) -> int {
  728. n := min(len(dst), len(src))
  729. if n > 0 {
  730. mem.copy(&dst[0], &src[0], n*size_of(T))
  731. }
  732. return n
  733. }
  734. double_params :: proc(a: $A, b: $B) -> A {
  735. return a + A(b)
  736. }
  737. fmt.println(double_params(12, 1.345))
  738. { // Polymorphic Types and Type Specialization
  739. Table_Slot :: struct(Key, Value: typeid) {
  740. occupied: bool,
  741. hash: u32,
  742. key: Key,
  743. value: Value,
  744. }
  745. TABLE_SIZE_MIN :: 32
  746. Table :: struct(Key, Value: typeid) {
  747. count: int,
  748. allocator: mem.Allocator,
  749. slots: []Table_Slot(Key, Value),
  750. }
  751. // Only allow types that are specializations of a (polymorphic) slice
  752. make_slice :: proc($T: typeid/[]$E, len: int) -> T {
  753. return make(T, len)
  754. }
  755. // Only allow types that are specializations of `Table`
  756. allocate :: proc(table: ^$T/Table, capacity: int) {
  757. c := context
  758. if table.allocator.procedure != nil {
  759. c.allocator = table.allocator
  760. }
  761. context = c
  762. table.slots = make_slice(type_of(table.slots), max(capacity, TABLE_SIZE_MIN))
  763. }
  764. expand :: proc(table: ^$T/Table) {
  765. c := context
  766. if table.allocator.procedure != nil {
  767. c.allocator = table.allocator
  768. }
  769. context = c
  770. old_slots := table.slots
  771. defer delete(old_slots)
  772. cap := max(2*len(table.slots), TABLE_SIZE_MIN)
  773. allocate(table, cap)
  774. for s in old_slots {
  775. if s.occupied {
  776. put(table, s.key, s.value)
  777. }
  778. }
  779. }
  780. // Polymorphic determination of a polymorphic struct
  781. // put :: proc(table: ^$T/Table, key: T.Key, value: T.Value) {
  782. put :: proc(table: ^Table($Key, $Value), key: Key, value: Value) {
  783. hash := get_hash(key) // Ad-hoc method which would fail in a different scope
  784. index := find_index(table, key, hash)
  785. if index < 0 {
  786. if f64(table.count) >= 0.75*f64(len(table.slots)) {
  787. expand(table)
  788. }
  789. assert(table.count <= len(table.slots))
  790. index = int(hash % u32(len(table.slots)))
  791. for table.slots[index].occupied {
  792. if index += 1; index >= len(table.slots) {
  793. index = 0
  794. }
  795. }
  796. table.count += 1
  797. }
  798. slot := &table.slots[index]
  799. slot.occupied = true
  800. slot.hash = hash
  801. slot.key = key
  802. slot.value = value
  803. }
  804. // find :: proc(table: ^$T/Table, key: T.Key) -> (T.Value, bool) {
  805. find :: proc(table: ^Table($Key, $Value), key: Key) -> (Value, bool) {
  806. hash := get_hash(key)
  807. index := find_index(table, key, hash)
  808. if index < 0 {
  809. return Value{}, false
  810. }
  811. return table.slots[index].value, true
  812. }
  813. find_index :: proc(table: ^Table($Key, $Value), key: Key, hash: u32) -> int {
  814. if len(table.slots) <= 0 {
  815. return -1
  816. }
  817. index := int(hash % u32(len(table.slots)))
  818. for table.slots[index].occupied {
  819. if table.slots[index].hash == hash {
  820. if table.slots[index].key == key {
  821. return index
  822. }
  823. }
  824. if index += 1; index >= len(table.slots) {
  825. index = 0
  826. }
  827. }
  828. return -1
  829. }
  830. get_hash :: proc(s: string) -> u32 { // fnv32a
  831. h: u32 = 0x811c9dc5
  832. for i in 0..<len(s) {
  833. h = (h ~ u32(s[i])) * 0x01000193
  834. }
  835. return h
  836. }
  837. table: Table(string, int)
  838. for i in 0..36 { put(&table, "Hellope", i) }
  839. for i in 0..42 { put(&table, "World!", i) }
  840. found, _ := find(&table, "Hellope")
  841. fmt.printf("`found` is %v\n", found)
  842. found, _ = find(&table, "World!")
  843. fmt.printf("`found` is %v\n", found)
  844. // I would not personally design a hash table like this in production
  845. // but this is a nice basic example
  846. // A better approach would either use a `u64` or equivalent for the key
  847. // and let the user specify the hashing function or make the user store
  848. // the hashing procedure with the table
  849. }
  850. { // Parametric polymorphic union
  851. Error :: enum {
  852. Foo0,
  853. Foo1,
  854. Foo2,
  855. Foo3,
  856. }
  857. Para_Union :: union(T: typeid) {T, Error}
  858. r: Para_Union(int)
  859. fmt.println(typeid_of(type_of(r)))
  860. fmt.println(r)
  861. r = 123
  862. fmt.println(r)
  863. r = Error.Foo0 // r = .Foo0; is allow too, see implicit selector expressions below
  864. fmt.println(r)
  865. }
  866. { // Polymorphic names
  867. foo :: proc($N: $I, $T: typeid) -> (res: [N]T) {
  868. // `N` is the constant value passed
  869. // `I` is the type of N
  870. // `T` is the type passed
  871. fmt.printf("Generating an array of type %v from the value %v of type %v\n",
  872. typeid_of(type_of(res)), N, typeid_of(I))
  873. for i in 0..<N {
  874. res[i] = T(i*i)
  875. }
  876. return
  877. }
  878. T :: int
  879. array := foo(4, T)
  880. for v, i in array {
  881. assert(v == T(i*i))
  882. }
  883. // Matrix multiplication
  884. mul :: proc(a: [$M][$N]$T, b: [N][$P]T) -> (c: [M][P]T) {
  885. for i in 0..<M {
  886. for j in 0..<P {
  887. for k in 0..<N {
  888. c[i][j] += a[i][k] * b[k][j]
  889. }
  890. }
  891. }
  892. return
  893. }
  894. x := [2][3]f32{
  895. {1, 2, 3},
  896. {3, 2, 1},
  897. }
  898. y := [3][2]f32{
  899. {0, 8},
  900. {6, 2},
  901. {8, 4},
  902. }
  903. z := mul(x, y)
  904. assert(z == {{36, 24}, {20, 32}})
  905. }
  906. }
  907. prefix_table := [?]string{
  908. "White",
  909. "Red",
  910. "Green",
  911. "Blue",
  912. "Octarine",
  913. "Black",
  914. }
  915. threading_example :: proc() {
  916. fmt.println("\n# threading_example")
  917. { // Basic Threads
  918. fmt.println("\n## Basic Threads")
  919. worker_proc :: proc(t: ^thread.Thread) {
  920. for iteration in 1..5 {
  921. fmt.printf("Thread %d is on iteration %d\n", t.user_index, iteration)
  922. fmt.printf("`%s`: iteration %d\n", prefix_table[t.user_index], iteration)
  923. time.sleep(1 * time.Millisecond)
  924. }
  925. }
  926. threads := make([dynamic]^thread.Thread, 0, len(prefix_table))
  927. defer delete(threads)
  928. for in prefix_table {
  929. if t := thread.create(worker_proc); t != nil {
  930. t.init_context = context
  931. t.user_index = len(threads)
  932. append(&threads, t)
  933. thread.start(t)
  934. }
  935. }
  936. for len(threads) > 0 {
  937. for i := 0; i < len(threads); /**/ {
  938. if t := threads[i]; thread.is_done(t) {
  939. fmt.printf("Thread %d is done\n", t.user_index)
  940. thread.destroy(t)
  941. ordered_remove(&threads, i)
  942. } else {
  943. i += 1
  944. }
  945. }
  946. }
  947. }
  948. { // Thread Pool
  949. fmt.println("\n## Thread Pool")
  950. task_proc :: proc(t: ^thread.Task) {
  951. index := t.user_index % len(prefix_table)
  952. for iteration in 1..5 {
  953. fmt.printf("Worker Task %d is on iteration %d\n", t.user_index, iteration)
  954. fmt.printf("`%s`: iteration %d\n", prefix_table[index], iteration)
  955. time.sleep(1 * time.Millisecond)
  956. }
  957. }
  958. pool: thread.Pool
  959. thread.pool_init(pool=&pool, thread_count=3)
  960. defer thread.pool_destroy(&pool)
  961. for i in 0..<30 {
  962. thread.pool_add_task(pool=&pool, procedure=task_proc, data=nil, user_index=i)
  963. }
  964. thread.pool_start(&pool)
  965. thread.pool_wait_and_process(&pool)
  966. }
  967. }
  968. array_programming :: proc() {
  969. fmt.println("\n# array programming")
  970. {
  971. a := [3]f32{1, 2, 3}
  972. b := [3]f32{5, 6, 7}
  973. c := a * b
  974. d := a + b
  975. e := 1 + (c - d) / 2
  976. fmt.printf("%.1f\n", e) // [0.5, 3.0, 6.5]
  977. }
  978. {
  979. a := [3]f32{1, 2, 3}
  980. b := swizzle(a, 2, 1, 0)
  981. assert(b == [3]f32{3, 2, 1})
  982. c := swizzle(a, 0, 0)
  983. assert(c == [2]f32{1, 1})
  984. assert(c == 1)
  985. }
  986. {
  987. Vector3 :: distinct [3]f32
  988. a := Vector3{1, 2, 3}
  989. b := Vector3{5, 6, 7}
  990. c := (a * b)/2 + 1
  991. d := c.x + c.y + c.z
  992. fmt.printf("%.1f\n", d) // 22.0
  993. cross :: proc(a, b: Vector3) -> Vector3 {
  994. i := swizzle(a, 1, 2, 0) * swizzle(b, 2, 0, 1)
  995. j := swizzle(a, 2, 0, 1) * swizzle(b, 1, 2, 0)
  996. return i - j
  997. }
  998. blah :: proc(a: Vector3) -> f32 {
  999. return a.x + a.y + a.z
  1000. }
  1001. x := cross(a, b)
  1002. fmt.println(x)
  1003. fmt.println(blah(x))
  1004. }
  1005. }
  1006. map_type :: proc() {
  1007. fmt.println("\n# map type")
  1008. m := make(map[string]int)
  1009. defer delete(m)
  1010. m["Bob"] = 2
  1011. m["Ted"] = 5
  1012. fmt.println(m["Bob"])
  1013. delete_key(&m, "Ted")
  1014. // If an element of a key does not exist, the zero value of the
  1015. // element will be returned. To check to see if an element exists
  1016. // can be done in two ways:
  1017. elem, ok := m["Bob"]
  1018. exists := "Bob" in m
  1019. _, _ = elem, ok
  1020. _ = exists
  1021. }
  1022. implicit_selector_expression :: proc() {
  1023. fmt.println("\n# implicit selector expression")
  1024. Foo :: enum {A, B, C}
  1025. f: Foo
  1026. f = Foo.A
  1027. f = .A
  1028. BAR :: bit_set[Foo]{.B, .C}
  1029. switch f {
  1030. case .A:
  1031. fmt.println("HITHER")
  1032. case .B:
  1033. fmt.println("NEVER")
  1034. case .C:
  1035. fmt.println("FOREVER")
  1036. }
  1037. my_map := make(map[Foo]int)
  1038. defer delete(my_map)
  1039. my_map[.A] = 123
  1040. my_map[Foo.B] = 345
  1041. fmt.println(my_map[.A] + my_map[Foo.B] + my_map[.C])
  1042. }
  1043. partial_switch :: proc() {
  1044. fmt.println("\n# partial_switch")
  1045. { // enum
  1046. Foo :: enum {
  1047. A,
  1048. B,
  1049. C,
  1050. D,
  1051. }
  1052. f := Foo.A
  1053. switch f {
  1054. case .A: fmt.println("A")
  1055. case .B: fmt.println("B")
  1056. case .C: fmt.println("C")
  1057. case .D: fmt.println("D")
  1058. case: fmt.println("?")
  1059. }
  1060. #partial switch f {
  1061. case .A: fmt.println("A")
  1062. case .D: fmt.println("D")
  1063. }
  1064. }
  1065. { // union
  1066. Foo :: union {int, bool}
  1067. f: Foo = 123
  1068. switch in f {
  1069. case int: fmt.println("int")
  1070. case bool: fmt.println("bool")
  1071. case:
  1072. }
  1073. #partial switch in f {
  1074. case bool: fmt.println("bool")
  1075. }
  1076. }
  1077. }
  1078. cstring_example :: proc() {
  1079. fmt.println("\n# cstring_example")
  1080. W :: "Hellope"
  1081. X :: cstring(W)
  1082. Y :: string(X)
  1083. w := W
  1084. _ = w
  1085. x: cstring = X
  1086. y: string = Y
  1087. z := string(x)
  1088. fmt.println(x, y, z)
  1089. fmt.println(len(x), len(y), len(z))
  1090. fmt.println(len(W), len(X), len(Y))
  1091. // IMPORTANT NOTE for cstring variables
  1092. // len(cstring) is O(N)
  1093. // cast(string)cstring is O(N)
  1094. }
  1095. bit_set_type :: proc() {
  1096. fmt.println("\n# bit_set type")
  1097. {
  1098. using Day :: enum {
  1099. Sunday,
  1100. Monday,
  1101. Tuesday,
  1102. Wednesday,
  1103. Thursday,
  1104. Friday,
  1105. Saturday,
  1106. }
  1107. Days :: distinct bit_set[Day]
  1108. WEEKEND :: Days{Sunday, Saturday}
  1109. d: Days
  1110. d = {Sunday, Monday}
  1111. e := d | WEEKEND
  1112. e |= {Monday}
  1113. fmt.println(d, e)
  1114. ok := Saturday in e // `in` is only allowed for `map` and `bit_set` types
  1115. fmt.println(ok)
  1116. if Saturday in e {
  1117. fmt.println("Saturday in", e)
  1118. }
  1119. X :: Saturday in WEEKEND // Constant evaluation
  1120. fmt.println(X)
  1121. fmt.println("Cardinality:", card(e))
  1122. }
  1123. {
  1124. x: bit_set['A'..'Z']
  1125. #assert(size_of(x) == size_of(u32))
  1126. y: bit_set[0..8; u16]
  1127. fmt.println(typeid_of(type_of(x))) // bit_set[A..Z]
  1128. fmt.println(typeid_of(type_of(y))) // bit_set[0..8; u16]
  1129. incl(&x, 'F')
  1130. assert('F' in x)
  1131. excl(&x, 'F')
  1132. assert('F' not_in x)
  1133. y |= {1, 4, 2}
  1134. assert(2 in y)
  1135. }
  1136. {
  1137. Letters :: bit_set['A'..'Z']
  1138. a := Letters{'A', 'B'}
  1139. b := Letters{'A', 'B', 'C', 'D', 'F'}
  1140. c := Letters{'A', 'B'}
  1141. assert(a <= b) // 'a' is a subset of 'b'
  1142. assert(b >= a) // 'b' is a superset of 'a'
  1143. assert(a < b) // 'a' is a strict subset of 'b'
  1144. assert(b > a) // 'b' is a strict superset of 'a'
  1145. assert(!(a < c)) // 'a' is a not strict subset of 'c'
  1146. assert(!(c > a)) // 'c' is a not strict superset of 'a'
  1147. }
  1148. }
  1149. deferred_procedure_associations :: proc() {
  1150. fmt.println("\n# deferred procedure associations")
  1151. @(deferred_out=closure)
  1152. open :: proc(s: string) -> bool {
  1153. fmt.println(s)
  1154. return true
  1155. }
  1156. closure :: proc(ok: bool) {
  1157. fmt.println("Goodbye?", ok)
  1158. }
  1159. if open("Welcome") {
  1160. fmt.println("Something in the middle, mate.")
  1161. }
  1162. }
  1163. reflection :: proc() {
  1164. fmt.println("\n# reflection")
  1165. Foo :: struct {
  1166. x: int `tag1`,
  1167. y: string `json:"y_field"`,
  1168. z: bool, // no tag
  1169. }
  1170. id := typeid_of(Foo)
  1171. names := reflect.struct_field_names(id)
  1172. types := reflect.struct_field_types(id)
  1173. tags := reflect.struct_field_tags(id)
  1174. assert(len(names) == len(types) && len(names) == len(tags))
  1175. fmt.println("Foo :: struct {")
  1176. for tag, i in tags {
  1177. name, type := names[i], types[i]
  1178. if tag != "" {
  1179. fmt.printf("\t%s: %T `%s`,\n", name, type, tag)
  1180. } else {
  1181. fmt.printf("\t%s: %T,\n", name, type)
  1182. }
  1183. }
  1184. fmt.println("}")
  1185. for tag, i in tags {
  1186. if val, ok := reflect.struct_tag_lookup(tag, "json"); ok {
  1187. fmt.printf("json: %s -> %s\n", names[i], val)
  1188. }
  1189. }
  1190. }
  1191. quaternions :: proc() {
  1192. // Not just an April Fool's Joke any more, but a fully working thing!
  1193. fmt.println("\n# quaternions")
  1194. { // Quaternion operations
  1195. q := 1 + 2i + 3j + 4k
  1196. r := quaternion(5, 6, 7, 8)
  1197. t := q * r
  1198. fmt.printf("(%v) * (%v) = %v\n", q, r, t)
  1199. v := q / r
  1200. fmt.printf("(%v) / (%v) = %v\n", q, r, v)
  1201. u := q + r
  1202. fmt.printf("(%v) + (%v) = %v\n", q, r, u)
  1203. s := q - r
  1204. fmt.printf("(%v) - (%v) = %v\n", q, r, s)
  1205. }
  1206. { // The quaternion types
  1207. q128: quaternion128 // 4xf32
  1208. q256: quaternion256 // 4xf64
  1209. q128 = quaternion(1, 0, 0, 0)
  1210. q256 = 1 // quaternion(1, 0, 0, 0)
  1211. }
  1212. { // Built-in procedures
  1213. q := 1 + 2i + 3j + 4k
  1214. fmt.println("q =", q)
  1215. fmt.println("real(q) =", real(q))
  1216. fmt.println("imag(q) =", imag(q))
  1217. fmt.println("jmag(q) =", jmag(q))
  1218. fmt.println("kmag(q) =", kmag(q))
  1219. fmt.println("conj(q) =", conj(q))
  1220. fmt.println("abs(q) =", abs(q))
  1221. }
  1222. { // Conversion of a complex type to a quaternion type
  1223. c := 1 + 2i
  1224. q := quaternion256(c)
  1225. fmt.println(c)
  1226. fmt.println(q)
  1227. }
  1228. { // Memory layout of Quaternions
  1229. q := 1 + 2i + 3j + 4k
  1230. a := transmute([4]f64)q
  1231. fmt.println("Quaternion memory layout: xyzw/(ijkr)")
  1232. fmt.println(q) // 1.000+2.000i+3.000j+4.000k
  1233. fmt.println(a) // [2.000, 3.000, 4.000, 1.000]
  1234. }
  1235. }
  1236. unroll_for_statement :: proc() {
  1237. fmt.println("\n#'#unroll for' statements")
  1238. // '#unroll for' works the same as if the 'inline' prefix did not
  1239. // exist but these ranged loops are explicitly unrolled which can
  1240. // be very very useful for certain optimizations
  1241. fmt.println("Ranges")
  1242. #unroll for x, i in 1..<4 {
  1243. fmt.println(x, i)
  1244. }
  1245. fmt.println("Strings")
  1246. #unroll for r, i in "Hello, 世界" {
  1247. fmt.println(r, i)
  1248. }
  1249. fmt.println("Arrays")
  1250. #unroll for elem, idx in ([4]int{1, 4, 9, 16}) {
  1251. fmt.println(elem, idx)
  1252. }
  1253. Foo_Enum :: enum {
  1254. A = 1,
  1255. B,
  1256. C = 6,
  1257. D,
  1258. }
  1259. fmt.println("Enum types")
  1260. #unroll for elem, idx in Foo_Enum {
  1261. fmt.println(elem, idx)
  1262. }
  1263. }
  1264. where_clauses :: proc() {
  1265. fmt.println("\n#procedure 'where' clauses")
  1266. { // Sanity checks
  1267. simple_sanity_check :: proc(x: [2]int)
  1268. where len(x) > 1,
  1269. type_of(x) == [2]int {
  1270. fmt.println(x)
  1271. }
  1272. }
  1273. { // Parametric polymorphism checks
  1274. cross_2d :: proc(a, b: $T/[2]$E) -> E
  1275. where intrinsics.type_is_numeric(E) {
  1276. return a.x*b.y - a.y*b.x
  1277. }
  1278. cross_3d :: proc(a, b: $T/[3]$E) -> T
  1279. where intrinsics.type_is_numeric(E) {
  1280. x := a.y*b.z - a.z*b.y
  1281. y := a.z*b.x - a.x*b.z
  1282. z := a.x*b.y - a.y*b.z
  1283. return T{x, y, z}
  1284. }
  1285. a := [2]int{1, 2}
  1286. b := [2]int{5, -3}
  1287. fmt.println(cross_2d(a, b))
  1288. x := [3]f32{1, 4, 9}
  1289. y := [3]f32{-5, 0, 3}
  1290. fmt.println(cross_3d(x, y))
  1291. // Failure case
  1292. // i := [2]bool{true, false}
  1293. // j := [2]bool{false, true}
  1294. // fmt.println(cross_2d(i, j))
  1295. }
  1296. { // Procedure groups usage
  1297. foo :: proc(x: [$N]int) -> bool
  1298. where N > 2 {
  1299. fmt.println(#procedure, "was called with the parameter", x)
  1300. return true
  1301. }
  1302. bar :: proc(x: [$N]int) -> bool
  1303. where 0 < N,
  1304. N <= 2 {
  1305. fmt.println(#procedure, "was called with the parameter", x)
  1306. return false
  1307. }
  1308. baz :: proc{foo, bar}
  1309. x := [3]int{1, 2, 3}
  1310. y := [2]int{4, 9}
  1311. ok_x := baz(x)
  1312. ok_y := baz(y)
  1313. assert(ok_x == true)
  1314. assert(ok_y == false)
  1315. }
  1316. { // Record types
  1317. Foo :: struct(T: typeid, N: int)
  1318. where intrinsics.type_is_integer(T),
  1319. N > 2 {
  1320. x: [N]T,
  1321. y: [N-2]T,
  1322. }
  1323. T :: i32
  1324. N :: 5
  1325. f: Foo(T, N)
  1326. #assert(size_of(f) == (N+N-2)*size_of(T))
  1327. }
  1328. }
  1329. when ODIN_OS == "windows" {
  1330. foreign import kernel32 "system:kernel32.lib"
  1331. }
  1332. foreign_system :: proc() {
  1333. fmt.println("\n#foreign system")
  1334. when ODIN_OS == "windows" {
  1335. // It is sometimes necessarily to interface with foreign code,
  1336. // such as a C library. In Odin, this is achieved through the
  1337. // foreign system. You can “import” a library into the code
  1338. // using the same semantics as a normal import declaration.
  1339. // This foreign import declaration will create a
  1340. // “foreign import name” which can then be used to associate
  1341. // entities within a foreign block.
  1342. foreign kernel32 {
  1343. ExitProcess :: proc "stdcall" (exit_code: u32) ---
  1344. }
  1345. // Foreign procedure declarations have the cdecl/c calling
  1346. // convention by default unless specified otherwise. Due to
  1347. // foreign procedures do not have a body declared within this
  1348. // code, you need append the --- symbol to the end to distinguish
  1349. // it as a procedure literal without a body and not a procedure type.
  1350. // The attributes system can be used to change specific properties
  1351. // of entities declared within a block:
  1352. @(default_calling_convention = "std")
  1353. foreign kernel32 {
  1354. @(link_name="GetLastError") get_last_error :: proc() -> i32 ---
  1355. }
  1356. // Example using the link_prefix attribute
  1357. @(default_calling_convention = "std")
  1358. @(link_prefix = "Get")
  1359. foreign kernel32 {
  1360. LastError :: proc() -> i32 ---
  1361. }
  1362. }
  1363. }
  1364. ranged_fields_for_array_compound_literals :: proc() {
  1365. fmt.println("\n#ranged fields for array compound literals")
  1366. { // Normal Array Literal
  1367. foo := [?]int{1, 4, 9, 16}
  1368. fmt.println(foo)
  1369. }
  1370. { // Indexed
  1371. foo := [?]int{
  1372. 3 = 16,
  1373. 1 = 4,
  1374. 2 = 9,
  1375. 0 = 1,
  1376. }
  1377. fmt.println(foo)
  1378. }
  1379. { // Ranges
  1380. i := 2
  1381. foo := [?]int {
  1382. 0 = 123,
  1383. 5..9 = 54,
  1384. 10..<16 = i*3 + (i-1)*2,
  1385. }
  1386. #assert(len(foo) == 16)
  1387. fmt.println(foo); // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
  1388. }
  1389. { // Slice and Dynamic Array support
  1390. i := 2
  1391. foo_slice := []int {
  1392. 0 = 123,
  1393. 5..9 = 54,
  1394. 10..<16 = i*3 + (i-1)*2,
  1395. }
  1396. assert(len(foo_slice) == 16)
  1397. fmt.println(foo_slice); // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
  1398. foo_dynamic_array := [dynamic]int {
  1399. 0 = 123,
  1400. 5..9 = 54,
  1401. 10..<16 = i*3 + (i-1)*2,
  1402. }
  1403. assert(len(foo_dynamic_array) == 16)
  1404. fmt.println(foo_dynamic_array); // [123, 0, 0, 0, 0, 54, 54, 54, 54, 54, 8, 8, 8, 8, 8]
  1405. }
  1406. }
  1407. deprecated_attribute :: proc() {
  1408. @(deprecated="Use foo_v2 instead")
  1409. foo_v1 :: proc(x: int) {
  1410. fmt.println("foo_v1")
  1411. }
  1412. foo_v2 :: proc(x: int) {
  1413. fmt.println("foo_v2")
  1414. }
  1415. // NOTE: Uncomment to see the warning messages
  1416. // foo_v1(1)
  1417. }
  1418. range_statements_with_multiple_return_values :: proc() {
  1419. // IMPORTANT NOTE(bill, 2019-11-02): This feature is subject to be changed/removed
  1420. fmt.println("\n#range statements with multiple return values")
  1421. My_Iterator :: struct {
  1422. index: int,
  1423. data: []i32,
  1424. }
  1425. make_my_iterator :: proc(data: []i32) -> My_Iterator {
  1426. return My_Iterator{data = data}
  1427. }
  1428. my_iterator :: proc(it: ^My_Iterator) -> (val: i32, idx: int, cond: bool) {
  1429. if cond = it.index < len(it.data); cond {
  1430. val = it.data[it.index]
  1431. idx = it.index
  1432. it.index += 1
  1433. }
  1434. return
  1435. }
  1436. data := make([]i32, 6)
  1437. for _, i in data {
  1438. data[i] = i32(i*i)
  1439. }
  1440. {
  1441. it := make_my_iterator(data)
  1442. for val in my_iterator(&it) {
  1443. fmt.println(val)
  1444. }
  1445. }
  1446. {
  1447. it := make_my_iterator(data)
  1448. for val, idx in my_iterator(&it) {
  1449. fmt.println(val, idx)
  1450. }
  1451. }
  1452. {
  1453. it := make_my_iterator(data)
  1454. for {
  1455. val, _, cond := my_iterator(&it)
  1456. if !cond {
  1457. break
  1458. }
  1459. fmt.println(val)
  1460. }
  1461. }
  1462. }
  1463. soa_struct_layout :: proc() {
  1464. // IMPORTANT NOTE(bill, 2019-11-03): This feature is subject to be changed/removed
  1465. // NOTE(bill): Most likely #soa [N]T
  1466. fmt.println("\n#SOA Struct Layout")
  1467. {
  1468. Vector3 :: struct {x, y, z: f32}
  1469. N :: 2
  1470. v_aos: [N]Vector3
  1471. v_aos[0].x = 1
  1472. v_aos[0].y = 4
  1473. v_aos[0].z = 9
  1474. fmt.println(len(v_aos))
  1475. fmt.println(v_aos[0])
  1476. fmt.println(v_aos[0].x)
  1477. fmt.println(&v_aos[0].x)
  1478. v_aos[1] = {0, 3, 4}
  1479. v_aos[1].x = 2
  1480. fmt.println(v_aos[1])
  1481. fmt.println(v_aos)
  1482. v_soa: #soa[N]Vector3
  1483. v_soa[0].x = 1
  1484. v_soa[0].y = 4
  1485. v_soa[0].z = 9
  1486. // Same syntax as AOS and treat as if it was an array
  1487. fmt.println(len(v_soa))
  1488. fmt.println(v_soa[0])
  1489. fmt.println(v_soa[0].x)
  1490. fmt.println(&v_soa[0].x)
  1491. v_soa[1] = {0, 3, 4}
  1492. v_soa[1].x = 2
  1493. fmt.println(v_soa[1])
  1494. // Can use SOA syntax if necessary
  1495. v_soa.x[0] = 1
  1496. v_soa.y[0] = 4
  1497. v_soa.z[0] = 9
  1498. fmt.println(v_soa.x[0])
  1499. // Same pointer addresses with both syntaxes
  1500. assert(&v_soa[0].x == &v_soa.x[0])
  1501. // Same fmt printing
  1502. fmt.println(v_aos)
  1503. fmt.println(v_soa)
  1504. }
  1505. {
  1506. // Works with arrays of length <= 4 which have the implicit fields xyzw/rgba
  1507. Vector3 :: distinct [3]f32
  1508. N :: 2
  1509. v_aos: [N]Vector3
  1510. v_aos[0].x = 1
  1511. v_aos[0].y = 4
  1512. v_aos[0].z = 9
  1513. v_soa: #soa[N]Vector3
  1514. v_soa[0].x = 1
  1515. v_soa[0].y = 4
  1516. v_soa[0].z = 9
  1517. }
  1518. {
  1519. // SOA Slices
  1520. // Vector3 :: struct {x, y, z: f32}
  1521. Vector3 :: struct {x: i8, y: i16, z: f32}
  1522. N :: 3
  1523. v: #soa[N]Vector3
  1524. v[0].x = 1
  1525. v[0].y = 4
  1526. v[0].z = 9
  1527. s: #soa[]Vector3
  1528. s = v[:]
  1529. assert(len(s) == N)
  1530. fmt.println(s)
  1531. fmt.println(s[0].x)
  1532. a := s[1:2]
  1533. assert(len(a) == 1)
  1534. fmt.println(a)
  1535. d: #soa[dynamic]Vector3
  1536. append_soa(&d, Vector3{1, 2, 3}, Vector3{4, 5, 9}, Vector3{-4, -4, 3})
  1537. fmt.println(d)
  1538. fmt.println(len(d))
  1539. fmt.println(cap(d))
  1540. fmt.println(d[:])
  1541. }
  1542. }
  1543. constant_literal_expressions :: proc() {
  1544. fmt.println("\n#constant literal expressions")
  1545. Bar :: struct {x, y: f32}
  1546. Foo :: struct {a, b: int, using c: Bar}
  1547. FOO_CONST :: Foo{b = 2, a = 1, c = {3, 4}}
  1548. fmt.println(FOO_CONST.a)
  1549. fmt.println(FOO_CONST.b)
  1550. fmt.println(FOO_CONST.c)
  1551. fmt.println(FOO_CONST.c.x)
  1552. fmt.println(FOO_CONST.c.y)
  1553. fmt.println(FOO_CONST.x); // using works as expected
  1554. fmt.println(FOO_CONST.y)
  1555. fmt.println("-------")
  1556. ARRAY_CONST :: [3]int{1 = 4, 2 = 9, 0 = 1}
  1557. fmt.println(ARRAY_CONST[0])
  1558. fmt.println(ARRAY_CONST[1])
  1559. fmt.println(ARRAY_CONST[2])
  1560. fmt.println("-------")
  1561. FOO_ARRAY_DEFAULTS :: [3]Foo{{}, {}, {}}
  1562. fmt.println(FOO_ARRAY_DEFAULTS[2].x)
  1563. fmt.println("-------")
  1564. Baz :: enum{A=5, B, C, D}
  1565. ENUM_ARRAY_CONST :: [Baz]int{.A .. .C = 1, .D = 16}
  1566. fmt.println(ENUM_ARRAY_CONST[.A])
  1567. fmt.println(ENUM_ARRAY_CONST[.B])
  1568. fmt.println(ENUM_ARRAY_CONST[.C])
  1569. fmt.println(ENUM_ARRAY_CONST[.D])
  1570. fmt.println("-------")
  1571. Partial_Baz :: enum{A=5, B, C, D=16}
  1572. #assert(len(Partial_Baz) < len(#partial [Partial_Baz]int))
  1573. PARTIAL_ENUM_ARRAY_CONST :: #partial [Partial_Baz]int{.A .. .C = 1, .D = 16}
  1574. fmt.println(PARTIAL_ENUM_ARRAY_CONST[.A])
  1575. fmt.println(PARTIAL_ENUM_ARRAY_CONST[.B])
  1576. fmt.println(PARTIAL_ENUM_ARRAY_CONST[.C])
  1577. fmt.println(PARTIAL_ENUM_ARRAY_CONST[.D])
  1578. fmt.println("-------")
  1579. STRING_CONST :: "Hellope!"
  1580. fmt.println(STRING_CONST[0])
  1581. fmt.println(STRING_CONST[2])
  1582. fmt.println(STRING_CONST[3])
  1583. fmt.println(STRING_CONST[0:5])
  1584. fmt.println(STRING_CONST[3:][:4])
  1585. }
  1586. union_maybe :: proc() {
  1587. fmt.println("\n#union #maybe")
  1588. Maybe :: union(T: typeid) #maybe {T}
  1589. i: Maybe(u8)
  1590. p: Maybe(^u8); // No tag is stored for pointers, nil is the sentinel value
  1591. #assert(size_of(i) == size_of(u8) + size_of(u8))
  1592. #assert(size_of(p) == size_of(^u8))
  1593. i = 123
  1594. x := i.?
  1595. y, y_ok := p.?
  1596. p = &x
  1597. z, z_ok := p.?
  1598. fmt.println(i, p)
  1599. fmt.println(x, &x)
  1600. fmt.println(y, y_ok)
  1601. fmt.println(z, z_ok)
  1602. }
  1603. dummy_procedure :: proc() {
  1604. fmt.println("dummy_procedure")
  1605. }
  1606. explicit_context_definition :: proc "c" () {
  1607. // Try commenting the following statement out below
  1608. context = runtime.default_context()
  1609. fmt.println("\n#explicit context definition")
  1610. dummy_procedure()
  1611. }
  1612. relative_data_types :: proc() {
  1613. fmt.println("\n#relative data types")
  1614. x: int = 123
  1615. ptr: #relative(i16) ^int
  1616. ptr = &x
  1617. fmt.println(ptr^)
  1618. arr := [3]int{1, 2, 3}
  1619. s := arr[:]
  1620. rel_slice: #relative(i16) []int
  1621. rel_slice = s
  1622. fmt.println(rel_slice)
  1623. fmt.println(rel_slice[:])
  1624. fmt.println(rel_slice[1])
  1625. }
  1626. main :: proc() {
  1627. when true {
  1628. the_basics()
  1629. control_flow()
  1630. named_proc_return_parameters()
  1631. explicit_procedure_overloading()
  1632. struct_type()
  1633. union_type()
  1634. using_statement()
  1635. implicit_context_system()
  1636. parametric_polymorphism()
  1637. array_programming()
  1638. map_type()
  1639. implicit_selector_expression()
  1640. partial_switch()
  1641. cstring_example()
  1642. bit_set_type()
  1643. deferred_procedure_associations()
  1644. reflection()
  1645. quaternions()
  1646. unroll_for_statement()
  1647. where_clauses()
  1648. foreign_system()
  1649. ranged_fields_for_array_compound_literals()
  1650. deprecated_attribute()
  1651. range_statements_with_multiple_return_values()
  1652. threading_example()
  1653. soa_struct_layout()
  1654. constant_literal_expressions()
  1655. union_maybe()
  1656. explicit_context_definition()
  1657. relative_data_types()
  1658. }
  1659. }