문법 정리 (Summary of the Grammar)

전체 공식 문법을 읽어보세요.

어휘 구조 (Lexical Structure)

Grammar of whitespace:

whitespace → whitespace-item whitespace? whitespace-item → line-break whitespace-item → inline-space whitespace-item → comment whitespace-item → multiline-comment whitespace-item → U+0000, U+000B, or U+000C

line-break → U+000A line-break → U+000D line-break → U+000D followed by U+000A

inline-spaces → inline-space inline-spaces? inline-space → U+0009 or U+0020

comment → // comment-text line-break multiline-comment → /* multiline-comment-text */

comment-text → comment-text-item comment-text? comment-text-item → Any Unicode scalar value except U+000A or U+000D

multiline-comment-text → multiline-comment-text-item multiline-comment-text? multiline-comment-text-item → multiline-comment multiline-comment-text-item → comment-text-item multiline-comment-text-item → Any Unicode scalar value except /* or */

Grammar of an identifier:

identifier → identifier-head identifier-characters? identifier → ` identifier-head identifier-characters? ` identifier → implicit-parameter-name identifier → property-wrapper-projection identifier-list → identifier | identifier , identifier-list

identifier-head → Upper- or lowercase letter A through Z identifier-head → _ identifier-head → U+00A8, U+00AA, U+00AD, U+00AF, U+00B2–U+00B5, or U+00B7–U+00BA identifier-head → U+00BC–U+00BE, U+00C0–U+00D6, U+00D8–U+00F6, or U+00F8–U+00FF identifier-head → U+0100–U+02FF, U+0370–U+167F, U+1681–U+180D, or U+180F–U+1DBF identifier-head → U+1E00–U+1FFF identifier-head → U+200B–U+200D, U+202A–U+202E, U+203F–U+2040, U+2054, or U+2060–U+206F identifier-head → U+2070–U+20CF, U+2100–U+218F, U+2460–U+24FF, or U+2776–U+2793 identifier-head → U+2C00–U+2DFF or U+2E80–U+2FFF identifier-head → U+3004–U+3007, U+3021–U+302F, U+3031–U+303F, or U+3040–U+D7FF identifier-head → U+F900–U+FD3D, U+FD40–U+FDCF, U+FDF0–U+FE1F, or U+FE30–U+FE44 identifier-head → U+FE47–U+FFFD identifier-head → U+10000–U+1FFFD, U+20000–U+2FFFD, U+30000–U+3FFFD, or U+40000–U+4FFFD identifier-head → U+50000–U+5FFFD, U+60000–U+6FFFD, U+70000–U+7FFFD, or U+80000–U+8FFFD identifier-head → U+90000–U+9FFFD, U+A0000–U+AFFFD, U+B0000–U+BFFFD, or U+C0000–U+CFFFD identifier-head → U+D0000–U+DFFFD or U+E0000–U+EFFFD

identifier-character → Digit 0 through 9 identifier-character → U+0300–U+036F, U+1DC0–U+1DFF, U+20D0–U+20FF, or U+FE20–U+FE2F identifier-character → identifier-head identifier-characters → identifier-character identifier-characters?

implicit-parameter-name → $ decimal-digits property-wrapper-projection → $ identifier-characters

Grammar of a literal:

literal → numeric-literal | string-literal | regular-expression-literal | boolean-literal | nil-literal

numeric-literal → -? integer-literal | -? floating-point-literal boolean-literal → true | false nil-literal → nil

Grammar of an integer literal:

integer-literal → binary-literal integer-literal → octal-literal integer-literal → decimal-literal integer-literal → hexadecimal-literal

binary-literal → 0b binary-digit binary-literal-characters? binary-digit → Digit 0 or 1 binary-literal-character → binary-digit | _ binary-literal-characters → binary-literal-character binary-literal-characters?

octal-literal → 0o octal-digit octal-literal-characters? octal-digit → Digit 0 through 7 octal-literal-character → octal-digit | _ octal-literal-characters → octal-literal-character octal-literal-characters?

decimal-literal → decimal-digit decimal-literal-characters? decimal-digit → Digit 0 through 9 decimal-digits → decimal-digit decimal-digits? decimal-literal-character → decimal-digit | _ decimal-literal-characters → decimal-literal-character decimal-literal-characters?

hexadecimal-literal → 0x hexadecimal-digit hexadecimal-literal-characters? hexadecimal-digit → Digit 0 through 9, a through f, or A through F hexadecimal-literal-character → hexadecimal-digit | _ hexadecimal-literal-characters → hexadecimal-literal-character hexadecimal-literal-characters?

Grammar of a floating-point literal:

floating-point-literal → decimal-literal decimal-fraction? decimal-exponent? floating-point-literal → hexadecimal-literal hexadecimal-fraction? hexadecimal-exponent

decimal-fraction → . decimal-literal decimal-exponent → floating-point-e sign? decimal-literal

hexadecimal-fraction → . hexadecimal-digit hexadecimal-literal-characters? hexadecimal-exponent → floating-point-p sign? decimal-literal

floating-point-e → e | E floating-point-p → p | P sign → + | -

Grammar of a string literal:

string-literal → static-string-literal | interpolated-string-literal

string-literal-opening-delimiter → extended-string-literal-delimiter? " string-literal-closing-delimiter → " extended-string-literal-delimiter?

static-string-literal → string-literal-opening-delimiter quoted-text? string-literal-closing-delimiter static-string-literal → multiline-string-literal-opening-delimiter multiline-quoted-text? multiline-string-literal-closing-delimiter

multiline-string-literal-opening-delimiter → extended-string-literal-delimiter? """ multiline-string-literal-closing-delimiter → """ extended-string-literal-delimiter? extended-string-literal-delimiter → # extended-string-literal-delimiter?

quoted-text → quoted-text-item quoted-text? quoted-text-item → escaped-character quoted-text-item → Any Unicode scalar value except ", \, U+000A, or U+000D

multiline-quoted-text → multiline-quoted-text-item multiline-quoted-text? multiline-quoted-text-item → escaped-character multiline-quoted-text-item → Any Unicode scalar value except \ multiline-quoted-text-item → escaped-newline

interpolated-string-literal → string-literal-opening-delimiter interpolated-text? string-literal-closing-delimiter interpolated-string-literal → multiline-string-literal-opening-delimiter multiline-interpolated-text? multiline-string-literal-closing-delimiter

interpolated-text → interpolated-text-item interpolated-text? interpolated-text-item → \( expression ) | quoted-text-item

multiline-interpolated-text → multiline-interpolated-text-item multiline-interpolated-text? multiline-interpolated-text-item → \( expression ) | multiline-quoted-text-item

escape-sequence → \ extended-string-literal-delimiter escaped-character → escape-sequence 0 | escape-sequence \ | escape-sequence t | escape-sequence n | escape-sequence r | escape-sequence " | escape-sequence ' escaped-character → escape-sequence u { unicode-scalar-digits } unicode-scalar-digits → Between one and eight hexadecimal digits

escaped-newline → escape-sequence inline-spaces? line-break

Grammar of a regular expression literal:

regular-expression-literal → regular-expression-literal-opening-delimiter regular-expression regular-expression-literal-closing-delimiter regular-expression → Any regular expression

regular-expression-literal-opening-delimiter → extended-regular-expression-literal-delimiter? / regular-expression-literal-closing-delimiter → / extended-regular-expression-literal-delimiter?

extended-regular-expression-literal-delimiter → # extended-regular-expression-literal-delimiter?

Grammar of operators:

operator → operator-head operator-characters? operator → dot-operator-head dot-operator-characters

operator-head → / | = | - | + | ! | * | % | < | > | & | | | ^ | ~ | ? operator-head → U+00A1–U+00A7 operator-head → U+00A9 or U+00AB operator-head → U+00AC or U+00AE operator-head → U+00B0–U+00B1 operator-head → U+00B6, U+00BB, U+00BF, U+00D7, or U+00F7 operator-head → U+2016–U+2017 operator-head → U+2020–U+2027 operator-head → U+2030–U+203E operator-head → U+2041–U+2053 operator-head → U+2055–U+205E operator-head → U+2190–U+23FF operator-head → U+2500–U+2775 operator-head → U+2794–U+2BFF operator-head → U+2E00–U+2E7F operator-head → U+3001–U+3003 operator-head → U+3008–U+3020 operator-head → U+3030

operator-character → operator-head operator-character → U+0300–U+036F operator-character → U+1DC0–U+1DFF operator-character → U+20D0–U+20FF operator-character → U+FE00–U+FE0F operator-character → U+FE20–U+FE2F operator-character → U+E0100–U+E01EF operator-characters → operator-character operator-characters?

dot-operator-head → . dot-operator-character → . | operator-character dot-operator-characters → dot-operator-character dot-operator-characters?

infix-operator → operator prefix-operator → operator postfix-operator → operator

타입 (Types)

Grammar of a type:

type → function-type type → array-type type → dictionary-type type → type-identifier type → tuple-type type → optional-type type → implicitly-unwrapped-optional-type type → protocol-composition-type type → opaque-type type → metatype-type type → any-type type → self-type type → ( type )

Grammar of a type annotation:

type-annotation → : attributes? inout? type

Grammar of a type identifier:

type-identifier → type-name generic-argument-clause? | type-name generic-argument-clause? . type-identifier type-name → identifier

Grammar of a tuple type:

tuple-type → ( ) | ( tuple-type-element , tuple-type-element-list ) tuple-type-element-list → tuple-type-element | tuple-type-element , tuple-type-element-list tuple-type-element → element-name type-annotation | type element-name → identifier

Grammar of a function type:

function-type → attributes? function-type-argument-clause async? throws-clause? -> type

function-type-argument-clause → ( ) function-type-argument-clause → ( function-type-argument-list ...? )

function-type-argument-list → function-type-argument | function-type-argument , function-type-argument-list function-type-argument → attributes? inout? type | argument-label type-annotation argument-label → identifier

throws-clause → throws | throws ( type )

Grammar of an array type:

array-type → [ type ]

Grammar of a dictionary type:

dictionary-type → [ type : type ]

Grammar of an optional type:

optional-type → type ?

Grammar of an implicitly unwrapped optional type:

implicitly-unwrapped-optional-type → type !

Grammar of a protocol composition type:

protocol-composition-type → type-identifier & protocol-composition-continuation protocol-composition-continuation → type-identifier | protocol-composition-type

Grammar of an opaque type:

opaque-type → some type

Grammar of a boxed protocol type:

boxed-protocol-type → any type

Grammar of a metatype type:

metatype-type → type . Type | type . Protocol

Grammar of an Any type:

any-type → Any

Grammar of a Self type:

self-type → Self

Grammar of a type inheritance clause:

type-inheritance-clause → : type-inheritance-list type-inheritance-list → attributes? type-identifier | attributes? type-identifier , type-inheritance-list

표현식 (Expressions)

Grammar of an expression:

expression → try-operator? await-operator? prefix-expression infix-expressions?

Grammar of a prefix expression:

prefix-expression → prefix-operator? postfix-expression prefix-expression → in-out-expression

Grammar of an in-out expression:

in-out-expression → & primary-expression

Grammar of a try expression:

try-operator → try | try ? | try !

Grammar of an await expression:

await-operator → await

Grammar of an infix expression:

infix-expression → infix-operator prefix-expression infix-expression → assignment-operator try-operator? await-operator? prefix-expression infix-expression → conditional-operator try-operator? await-operator? prefix-expression infix-expression → type-casting-operator infix-expressions → infix-expression infix-expressions?

Grammar of an assignment operator:

assignment-operator → =

Grammar of a conditional operator:

conditional-operator → ? expression :

Grammar of a type-casting operator:

type-casting-operator → is type type-casting-operator → as type type-casting-operator → as ? type type-casting-operator → as ! type

Grammar of a primary expression:

primary-expression → identifier generic-argument-clause? primary-expression → literal-expression primary-expression → self-expression primary-expression → superclass-expression primary-expression → conditional-expression primary-expression → closure-expression primary-expression → parenthesized-expression primary-expression → tuple-expression primary-expression → implicit-member-expression primary-expression → wildcard-expression primary-expression → macro-expansion-expression primary-expression → key-path-expression primary-expression → selector-expression primary-expression → key-path-string-expression

Grammar of a literal expression:

literal-expression → literal literal-expression → array-literal | dictionary-literal | playground-literal

array-literal → [ array-literal-items? ] array-literal-items → array-literal-item ,? | array-literal-item , array-literal-items array-literal-item → expression

dictionary-literal → [ dictionary-literal-items ] | [ : ] dictionary-literal-items → dictionary-literal-item ,? | dictionary-literal-item , dictionary-literal-items dictionary-literal-item → expression : expression

playground-literal → #colorLiteral ( red : expression , green : expression , blue : expression , alpha : expression ) playground-literal → #fileLiteral ( resourceName : expression ) playground-literal → #imageLiteral ( resourceName : expression )

Grammar of a self expression:

self-expression → self | self-method-expression | self-subscript-expression | self-initializer-expression

self-method-expression → self . identifier self-subscript-expression → self [ function-call-argument-list ] self-initializer-expression → self . init

Grammar of a superclass expression:

superclass-expression → superclass-method-expression | superclass-subscript-expression | superclass-initializer-expression

superclass-method-expression → super . identifier superclass-subscript-expression → super [ function-call-argument-list ] superclass-initializer-expression → super . init

Grammar of a conditional expression:

conditional-expression → if-expression | switch-expression

if-expression → if condition-list { statement } if-expression-tail if-expression-tail → else if-expression if-expression-tail → else { statement }

switch-expression → switch expression { switch-expression-cases } switch-expression-cases → switch-expression-case switch-expression-cases? switch-expression-case → case-label statement switch-expression-case → default-label statement

Grammar of a closure expression:

closure-expression → { attributes? closure-signature? statements? }

closure-signature → capture-list? closure-parameter-clause async? throws-clause? function-result? in closure-signature → capture-list in

closure-parameter-clause → ( ) | ( closure-parameter-list ) | identifier-list closure-parameter-list → closure-parameter | closure-parameter , closure-parameter-list closure-parameter → closure-parameter-name type-annotation? closure-parameter → closure-parameter-name type-annotation ... closure-parameter-name → identifier

capture-list → [ capture-list-items ] capture-list-items → capture-list-item | capture-list-item , capture-list-items capture-list-item → capture-specifier? identifier capture-list-item → capture-specifier? identifier = expression capture-list-item → capture-specifier? self-expression capture-specifier → weak | unowned | unowned(safe) | unowned(unsafe)

Grammar of an implicit member expression:

implicit-member-expression → . identifier implicit-member-expression → . identifier . postfix-expression

Grammar of a parenthesized expression:

parenthesized-expression → ( expression )

Grammar of a tuple expression:

tuple-expression → ( ) | ( tuple-element , tuple-element-list ) tuple-element-list → tuple-element | tuple-element , tuple-element-list tuple-element → expression | identifier : expression

Grammar of a wildcard expression:

wildcard-expression → _

Grammar of a macro-expansion expression:

macro-expansion-expression → # identifier generic-argument-clause? function-call-argument-clause? trailing-closures?

Grammar of a key-path expression:

key-path-expression → \ type? . key-path-components key-path-components → key-path-component | key-path-component . key-path-components key-path-component → identifier key-path-postfixes? | key-path-postfixes

key-path-postfixes → key-path-postfix key-path-postfixes? key-path-postfix → ? | ! | self | [ function-call-argument-list ]

Grammar of a selector expression:

selector-expression → #selector ( expression ) selector-expression → #selector ( getter: expression ) selector-expression → #selector ( setter: expression )

Grammar of a key-path string expression:

key-path-string-expression → #keyPath ( expression )

Grammar of a postfix expression:

postfix-expression → primary-expression postfix-expression → postfix-expression postfix-operator postfix-expression → function-call-expression postfix-expression → initializer-expression postfix-expression → explicit-member-expression postfix-expression → postfix-self-expression postfix-expression → subscript-expression postfix-expression → forced-value-expression postfix-expression → optional-chaining-expression

Grammar of a function call expression:

function-call-expression → postfix-expression function-call-argument-clause function-call-expression → postfix-expression function-call-argument-clause? trailing-closures

function-call-argument-clause → ( ) | ( function-call-argument-list ) function-call-argument-list → function-call-argument | function-call-argument , function-call-argument-list function-call-argument → expression | identifier : expression function-call-argument → operator | identifier : operator

trailing-closures → closure-expression labeled-trailing-closures? labeled-trailing-closures → labeled-trailing-closure labeled-trailing-closures? labeled-trailing-closure → identifier : closure-expression

Grammar of an initializer expression:

initializer-expression → postfix-expression . init initializer-expression → postfix-expression . init ( argument-names )

Grammar of an explicit member expression:

explicit-member-expression → postfix-expression . decimal-digits explicit-member-expression → postfix-expression . identifier generic-argument-clause? explicit-member-expression → postfix-expression . identifier ( argument-names ) explicit-member-expression → postfix-expression conditional-compilation-block

argument-names → argument-name argument-names? argument-name → identifier :

Grammar of a postfix self expression:

postfix-self-expression → postfix-expression . self

Grammar of a subscript expression:

subscript-expression → postfix-expression [ function-call-argument-list ]

Grammar of a forced-value expression:

forced-value-expression → postfix-expression !

Grammar of an optional-chaining expression:

optional-chaining-expression → postfix-expression ?

구문 (Statements)

Grammar of a statement:

statement → expression ;? statement → declaration ;? statement → loop-statement ;? statement → branch-statement ;? statement → labeled-statement ;? statement → control-transfer-statement ;? statement → defer-statement ;? statement → do-statement ;? statement → compiler-control-statement statements → statement statements?

Grammar of a loop statement:

loop-statement → for-in-statement loop-statement → while-statement loop-statement → repeat-while-statement

Grammar of a for-in statement:

for-in-statement → for case? pattern in expression where-clause? code-block

Grammar of a while statement:

while-statement → while condition-list code-block

condition-list → condition | condition , condition-list condition → expression | availability-condition | case-condition | optional-binding-condition

case-condition → case pattern initializer optional-binding-condition → let pattern initializer? | var pattern initializer?

Grammar of a repeat-while statement:

repeat-while-statement → repeat code-block while expression

Grammar of a branch statement:

branch-statement → if-statement branch-statement → guard-statement branch-statement → switch-statement

Grammar of an if statement:

if-statement → if condition-list code-block else-clause? else-clause → else code-block | else if-statement

Grammar of a guard statement:

guard-statement → guard condition-list else code-block

Grammar of a switch statement:

switch-statement → switch expression { switch-cases? } switch-cases → switch-case switch-cases? switch-case → case-label statements switch-case → default-label statements switch-case → conditional-switch-case

case-label → attributes? case case-item-list : case-item-list → pattern where-clause? | pattern where-clause? , case-item-list default-label → attributes? default :

where-clause → where where-expression where-expression → expression

conditional-switch-case → switch-if-directive-clause switch-elseif-directive-clauses? switch-else-directive-clause? endif-directive switch-if-directive-clause → if-directive compilation-condition switch-cases? switch-elseif-directive-clauses → elseif-directive-clause switch-elseif-directive-clauses? switch-elseif-directive-clause → elseif-directive compilation-condition switch-cases? switch-else-directive-clause → else-directive switch-cases?

Grammar of a labeled statement:

labeled-statement → statement-label loop-statement labeled-statement → statement-label if-statement labeled-statement → statement-label switch-statement labeled-statement → statement-label do-statement

statement-label → label-name : label-name → identifier

Grammar of a control transfer statement:

control-transfer-statement → break-statement control-transfer-statement → continue-statement control-transfer-statement → fallthrough-statement control-transfer-statement → return-statement control-transfer-statement → throw-statement

Grammar of a break statement:

break-statement → break label-name?

Grammar of a continue statement:

continue-statement → continue label-name?

Grammar of a fallthrough statement:

fallthrough-statement → fallthrough

Grammar of a return statement:

return-statement → return expression?

Grammar of a throw statement:

throw-statement → throw expression

Grammar of a defer statement:

defer-statement → defer code-block

Grammar of a do statement:

do-statement → do throws-clause? code-block catch-clauses? catch-clauses → catch-clause catch-clauses? catch-clause → catch catch-pattern-list? code-block catch-pattern-list → catch-pattern | catch-pattern , catch-pattern-list catch-pattern → pattern where-clause?

Grammar of a compiler control statement:

compiler-control-statement → conditional-compilation-block compiler-control-statement → line-control-statement compiler-control-statement → diagnostic-statement

Grammar of a conditional compilation block:

conditional-compilation-block → if-directive-clause elseif-directive-clauses? else-directive-clause? endif-directive

if-directive-clause → if-directive compilation-condition statements? elseif-directive-clauses → elseif-directive-clause elseif-directive-clauses? elseif-directive-clause → elseif-directive compilation-condition statements? else-directive-clause → else-directive statements? if-directive → #if elseif-directive → #elseif else-directive → #else endif-directive → #endif

compilation-condition → platform-condition compilation-condition → identifier compilation-condition → boolean-literal compilation-condition → ( compilation-condition ) compilation-condition → ! compilation-condition compilation-condition → compilation-condition && compilation-condition compilation-condition → compilation-condition || compilation-condition

platform-condition → os ( operating-system ) platform-condition → arch ( architecture ) platform-condition → swift ( >= swift-version ) | swift ( < swift-version ) platform-condition → compiler ( >= swift-version ) | compiler ( < swift-version ) platform-condition → canImport ( import-path ) platform-condition → targetEnvironment ( environment )

operating-system → macOS | iOS | watchOS | tvOS | visionOS | Linux | Windows architecture → i386 | x86_64 | arm | arm64 swift-version → decimal-digits swift-version-continuation? swift-version-continuation → . decimal-digits swift-version-continuation? environment → simulator | macCatalyst

Grammar of a line control statement:

line-control-statement → #sourceLocation ( file: file-path , line: line-number ) line-control-statement → #sourceLocation ( ) line-number → A decimal integer greater than zero file-path → static-string-literal

Grammar of an availability condition:

availability-condition → #available ( availability-arguments ) availability-condition → #unavailable ( availability-arguments ) availability-arguments → availability-argument | availability-argument , availability-arguments availability-argument → platform-name platform-version availability-argument → *

platform-name → iOS | iOSApplicationExtension platform-name → macOS | macOSApplicationExtension platform-name → macCatalyst | macCatalystApplicationExtension platform-name → watchOS | watchOSApplicationExtension platform-name → tvOS | tvOSApplicationExtension platform-name → visionOS | visionOSApplicationExtension platform-version → decimal-digits platform-version → decimal-digits . decimal-digits platform-version → decimal-digits . decimal-digits . decimal-digits

선언 (Declarations)

Grammar of a declaration:

declaration → import-declaration declaration → constant-declaration declaration → variable-declaration declaration → typealias-declaration declaration → function-declaration declaration → enum-declaration declaration → struct-declaration declaration → class-declaration declaration → actor-declaration declaration → protocol-declaration declaration → initializer-declaration declaration → deinitializer-declaration declaration → extension-declaration declaration → subscript-declaration declaration → operator-declaration declaration → precedence-group-declaration

Grammar of a top-level declaration:

top-level-declaration → statements?

Grammar of a code block:

code-block → { statements? }

Grammar of an import declaration:

import-declaration → attributes? import import-kind? import-path

import-kind → typealias | struct | class | enum | protocol | let | var | func import-path → identifier | identifier . import-path

Grammar of a constant declaration:

constant-declaration → attributes? declaration-modifiers? let pattern-initializer-list

pattern-initializer-list → pattern-initializer | pattern-initializer , pattern-initializer-list pattern-initializer → pattern initializer? initializer → = expression

Grammar of a variable declaration:

variable-declaration → variable-declaration-head pattern-initializer-list variable-declaration → variable-declaration-head variable-name type-annotation code-block variable-declaration → variable-declaration-head variable-name type-annotation getter-setter-block variable-declaration → variable-declaration-head variable-name type-annotation getter-setter-keyword-block variable-declaration → variable-declaration-head variable-name initializer willSet-didSet-block variable-declaration → variable-declaration-head variable-name type-annotation initializer? willSet-didSet-block

variable-declaration-head → attributes? declaration-modifiers? var variable-name → identifier

getter-setter-block → code-block getter-setter-block → { getter-clause setter-clause? } getter-setter-block → { setter-clause getter-clause } getter-clause → attributes? mutation-modifier? get code-block setter-clause → attributes? mutation-modifier? set setter-name? code-block setter-name → ( identifier )

getter-setter-keyword-block → { getter-keyword-clause setter-keyword-clause? } getter-setter-keyword-block → { setter-keyword-clause getter-keyword-clause } getter-keyword-clause → attributes? mutation-modifier? get setter-keyword-clause → attributes? mutation-modifier? set

willSet-didSet-block → { willSet-clause didSet-clause? } willSet-didSet-block → { didSet-clause willSet-clause? } willSet-clause → attributes? willSet setter-name? code-block didSet-clause → attributes? didSet setter-name? code-block

Grammar of a type alias declaration:

typealias-declaration → attributes? access-level-modifier? typealias typealias-name generic-parameter-clause? typealias-assignment typealias-name → identifier typealias-assignment → = type

Grammar of a function declaration:

function-declaration → function-head function-name generic-parameter-clause? function-signature generic-where-clause? function-body?

function-head → attributes? declaration-modifiers? func function-name → identifier | operator

function-signature → parameter-clause async? throws-clause? function-result? function-signature → parameter-clause async? rethrows function-result? function-result → -> attributes? type function-body → code-block

parameter-clause → ( ) | ( parameter-list ) parameter-list → parameter | parameter , parameter-list parameter → external-parameter-name? local-parameter-name parameter-type-annotation default-argument-clause? parameter → external-parameter-name? local-parameter-name parameter-type-annotation parameter → external-parameter-name? local-parameter-name parameter-type-annotation ...

external-parameter-name → identifier local-parameter-name → identifier parameter-type-annotation → : attributes? parameter-modifier? type parameter-modifier → inout | borrowing | consuming default-argument-clause → = expression

Grammar of an enumeration declaration:

enum-declaration → attributes? access-level-modifier? union-style-enum enum-declaration → attributes? access-level-modifier? raw-value-style-enum

union-style-enum → indirect? enum enum-name generic-parameter-clause? type-inheritance-clause? generic-where-clause? { union-style-enum-members? } union-style-enum-members → union-style-enum-member union-style-enum-members? union-style-enum-member → declaration | union-style-enum-case-clause | compiler-control-statement union-style-enum-case-clause → attributes? indirect? case union-style-enum-case-list union-style-enum-case-list → union-style-enum-case | union-style-enum-case , union-style-enum-case-list union-style-enum-case → enum-case-name tuple-type? enum-name → identifier enum-case-name → identifier

raw-value-style-enum → enum enum-name generic-parameter-clause? type-inheritance-clause generic-where-clause? { raw-value-style-enum-members } raw-value-style-enum-members → raw-value-style-enum-member raw-value-style-enum-members? raw-value-style-enum-member → declaration | raw-value-style-enum-case-clause | compiler-control-statement raw-value-style-enum-case-clause → attributes? case raw-value-style-enum-case-list raw-value-style-enum-case-list → raw-value-style-enum-case | raw-value-style-enum-case , raw-value-style-enum-case-list raw-value-style-enum-case → enum-case-name raw-value-assignment? raw-value-assignment → = raw-value-literal raw-value-literal → numeric-literal | static-string-literal | boolean-literal

Grammar of a structure declaration:

struct-declaration → attributes? access-level-modifier? struct struct-name generic-parameter-clause? type-inheritance-clause? generic-where-clause? struct-body struct-name → identifier struct-body → { struct-members? }

struct-members → struct-member struct-members? struct-member → declaration | compiler-control-statement

Grammar of a class declaration:

class-declaration → attributes? access-level-modifier? final? class class-name generic-parameter-clause? type-inheritance-clause? generic-where-clause? class-body class-declaration → attributes? final access-level-modifier? class class-name generic-parameter-clause? type-inheritance-clause? generic-where-clause? class-body class-name → identifier class-body → { class-members? }

class-members → class-member class-members? class-member → declaration | compiler-control-statement

Grammar of an actor declaration:

actor-declaration → attributes? access-level-modifier? actor actor-name generic-parameter-clause? type-inheritance-clause? generic-where-clause? actor-body actor-name → identifier actor-body → { actor-members? }

actor-members → actor-member actor-members? actor-member → declaration | compiler-control-statement

Grammar of a protocol declaration:

protocol-declaration → attributes? access-level-modifier? protocol protocol-name type-inheritance-clause? generic-where-clause? protocol-body protocol-name → identifier protocol-body → { protocol-members? }

protocol-members → protocol-member protocol-members? protocol-member → protocol-member-declaration | compiler-control-statement

protocol-member-declaration → protocol-property-declaration protocol-member-declaration → protocol-method-declaration protocol-member-declaration → protocol-initializer-declaration protocol-member-declaration → protocol-subscript-declaration protocol-member-declaration → protocol-associated-type-declaration protocol-member-declaration → typealias-declaration

Grammar of a protocol property declaration:

protocol-property-declaration → variable-declaration-head variable-name type-annotation getter-setter-keyword-block

Grammar of a protocol method declaration:

protocol-method-declaration → function-head function-name generic-parameter-clause? function-signature generic-where-clause?

Grammar of a protocol initializer declaration:

protocol-initializer-declaration → initializer-head generic-parameter-clause? parameter-clause throws-clause? generic-where-clause? protocol-initializer-declaration → initializer-head generic-parameter-clause? parameter-clause rethrows generic-where-clause?

Grammar of a protocol subscript declaration:

protocol-subscript-declaration → subscript-head subscript-result generic-where-clause? getter-setter-keyword-block

Grammar of a protocol associated type declaration:

protocol-associated-type-declaration → attributes? access-level-modifier? associatedtype typealias-name type-inheritance-clause? typealias-assignment? generic-where-clause?

Grammar of an initializer declaration:

initializer-declaration → initializer-head generic-parameter-clause? parameter-clause async? throws-clause? generic-where-clause? initializer-body initializer-declaration → initializer-head generic-parameter-clause? parameter-clause async? rethrows generic-where-clause? initializer-body initializer-head → attributes? declaration-modifiers? init initializer-head → attributes? declaration-modifiers? init ? initializer-head → attributes? declaration-modifiers? init ! initializer-body → code-block

Grammar of a deinitializer declaration:

deinitializer-declaration → attributes? deinit code-block

Grammar of an extension declaration:

extension-declaration → attributes? access-level-modifier? extension type-identifier type-inheritance-clause? generic-where-clause? extension-body extension-body → { extension-members? }

extension-members → extension-member extension-members? extension-member → declaration | compiler-control-statement

Grammar of a subscript declaration:

subscript-declaration → subscript-head subscript-result generic-where-clause? code-block subscript-declaration → subscript-head subscript-result generic-where-clause? getter-setter-block subscript-declaration → subscript-head subscript-result generic-where-clause? getter-setter-keyword-block subscript-head → attributes? declaration-modifiers? subscript generic-parameter-clause? parameter-clause subscript-result → -> attributes? type

Grammar of a macro declaration:

macro-declaration → macro-head identifier generic-parameter-clause? macro-signature macro-definition? generic-where-clause macro-head → attributes? declaration-modifiers? macro macro-signature → parameter-clause macro-function-signature-result? macro-function-signature-result → -> type macro-definition → = expression

Grammar of an operator declaration:

operator-declaration → prefix-operator-declaration | postfix-operator-declaration | infix-operator-declaration

prefix-operator-declaration → prefix operator operator postfix-operator-declaration → postfix operator operator infix-operator-declaration → infix operator operator infix-operator-group?

infix-operator-group → : precedence-group-name

Grammar of a precedence group declaration:

precedence-group-declaration → precedencegroup precedence-group-name { precedence-group-attributes? }

precedence-group-attributes → precedence-group-attribute precedence-group-attributes? precedence-group-attribute → precedence-group-relation precedence-group-attribute → precedence-group-assignment precedence-group-attribute → precedence-group-associativity

precedence-group-relation → higherThan : precedence-group-names precedence-group-relation → lowerThan : precedence-group-names

precedence-group-assignment → assignment : boolean-literal

precedence-group-associativity → associativity : left precedence-group-associativity → associativity : right precedence-group-associativity → associativity : none

precedence-group-names → precedence-group-name | precedence-group-name , precedence-group-names precedence-group-name → identifier

Grammar of a declaration modifier:

declaration-modifier → class | convenience | dynamic | final | infix | lazy | optional | override | postfix | prefix | required | static | unowned | unowned ( safe ) | unowned ( unsafe ) | weak declaration-modifier → access-level-modifier declaration-modifier → mutation-modifier declaration-modifier → actor-isolation-modifier declaration-modifiers → declaration-modifier declaration-modifiers?

access-level-modifier → private | private ( set ) access-level-modifier → fileprivate | fileprivate ( set ) access-level-modifier → internal | internal ( set ) access-level-modifier → package | package ( set ) access-level-modifier → public | public ( set ) access-level-modifier → open | open ( set )

mutation-modifier → mutating | nonmutating

actor-isolation-modifier → nonisolated

속성 (Attributes)

Grammar of an attribute:

attribute → @ attribute-name attribute-argument-clause? attribute-name → identifier attribute-argument-clause → ( balanced-tokens? ) attributes → attribute attributes?

balanced-tokens → balanced-token balanced-tokens? balanced-token → ( balanced-tokens? ) balanced-token → [ balanced-tokens? ] balanced-token → { balanced-tokens? } balanced-token → Any identifier, keyword, literal, or operator balanced-token → Any punctuation except (, ), [, ], {, or }

패턴 (Patterns)

Grammar of a pattern:

pattern → wildcard-pattern type-annotation? pattern → identifier-pattern type-annotation? pattern → value-binding-pattern pattern → tuple-pattern type-annotation? pattern → enum-case-pattern pattern → optional-pattern pattern → type-casting-pattern pattern → expression-pattern

Grammar of a wildcard pattern:

wildcard-pattern → _

Grammar of an identifier pattern:

identifier-pattern → identifier

Grammar of a value-binding pattern:

value-binding-pattern → var pattern | let pattern

Grammar of a tuple pattern:

tuple-pattern → ( tuple-pattern-element-list? ) tuple-pattern-element-list → tuple-pattern-element | tuple-pattern-element , tuple-pattern-element-list tuple-pattern-element → pattern | identifier : pattern

Grammar of an enumeration case pattern:

enum-case-pattern → type-identifier? . enum-case-name tuple-pattern?

Grammar of an optional pattern:

optional-pattern → identifier-pattern ?

Grammar of a type casting pattern:

type-casting-pattern → is-pattern | as-pattern is-pattern → is type as-pattern → pattern as type

Grammar of an expression pattern:

expression-pattern → expression

제네릭 매개변수와 인자 (Generic Parameters and Arguments)

Grammar of a generic parameter clause:

generic-parameter-clause → < generic-parameter-list > generic-parameter-list → generic-parameter | generic-parameter , generic-parameter-list generic-parameter → type-name generic-parameter → type-name : type-identifier generic-parameter → type-name : protocol-composition-type

generic-where-clause → where requirement-list requirement-list → requirement | requirement , requirement-list requirement → conformance-requirement | same-type-requirement

conformance-requirement → type-identifier : type-identifier conformance-requirement → type-identifier : protocol-composition-type same-type-requirement → type-identifier == type

Grammar of a generic argument clause:

generic-argument-clause → < generic-argument-list > generic-argument-list → generic-argument | generic-argument , generic-argument-list generic-argument → type

Beta Software:

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

Learn more about using Apple's beta software.