Summary of the Grammar

Grammar of whitespace

whitespace → whitespace-item opt

whitespace-item → line-break

whitespace-item →

whitespace-item → comment

whitespace-item →

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 opt

inline-space → U+0009 or U+0020

comment → comment-text

multiline-comment → /* multiline-comment-text */

comment-text → comment-text opt

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

multiline-comment-text → multiline-comment-text opt

multiline-comment-text-item →

multiline-comment-text-item → comment-text-item

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

Grammar of an identifier

identifier → identifier-characters opt

identifier → ` identifier-characters opt `

identifier →

identifier → property-wrapper-projection

identifier-list → | identifier ,

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-characters opt

implicit-parameter-name → $

property-wrapper-projection → $ identifier-characters

Grammar of a literal

literal → | string-literal | | nil-literal

numeric-literal → -opt | -opt floating-point-literal

boolean-literal → true | false

nil-literal → nil

Grammar of an integer literal

integer-literal →

integer-literal → octal-literal

integer-literal →

integer-literal → hexadecimal-literal

binary-literal → 0b binary-literal-characters opt

binary-digit → Digit 0 or 1

binary-literal-character → | _

binary-literal-characters → binary-literal-character opt

octal-literal → 0o octal-digit opt

octal-digit → Digit 0 through 7

octal-literal-character → octal-digit | _

octal-literal-characters → octal-literal-characters opt

decimal-literal → decimal-literal-characters opt

decimal-digit → Digit 0 through 9

decimal-digits → decimal-digits opt

decimal-literal-character → | _

decimal-literal-characters → decimal-literal-character opt

hexadecimal-literal → 0x hexadecimal-digit opt

hexadecimal-digit → Digit 0 through 9, a through f, or A through F

hexadecimal-literal-character → hexadecimal-digit | _

hexadecimal-literal-characters → hexadecimal-literal-characters opt

Grammar of a floating-point literal

floating-point-literal → decimal-fraction opt opt

floating-point-literal → hexadecimal-literal opt hexadecimal-exponent

decimal-fraction → .

decimal-exponent → floating-point-e opt decimal-literal

hexadecimal-fraction → . hexadecimal-literal-characters opt

hexadecimal-exponent → sign opt

floating-point-e → e | E

floating-point-p → p | P

sign → + | -

Grammar of a string literal

string-literal → static-string-literal |

string-literal-opening-delimiter → extended-string-literal-delimiter opt "

string-literal-closing-delimiter → " opt

static-string-literal → string-literal-opening-delimiter opt string-literal-closing-delimiter

static-string-literal → multiline-quoted-text opt

multiline-string-literal-opening-delimiter → extended-string-literal-delimiter """

multiline-string-literal-closing-delimiter → """

extended-string-literal-delimiter → # extended-string-literal-delimiter opt

quoted-text → quoted-text opt

quoted-text-item →

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

multiline-quoted-text → multiline-quoted-text-item opt

multiline-quoted-text-item → escaped-character

multiline-quoted-text-item → Any Unicode scalar value except \

multiline-quoted-text-item →

interpolated-string-literal → string-literal-opening-delimiter opt string-literal-closing-delimiter

interpolated-string-literal → multiline-interpolated-text opt

interpolated-text → interpolated-text-item opt

interpolated-text-item → \( expression ) |

multiline-interpolated-text → multiline-interpolated-text-item opt

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

escape-sequence → \ extended-string-literal-delimiter

escaped-character → 0 | escape-sequence \ | t | escape-sequence n | r | escape-sequence " | '

escaped-character → escape-sequence u { }

unicode-scalar-digits → Between one and eight hexadecimal digits

escaped-newline → escape-sequence opt line-break

Grammar of operators

operator → operator-characters opt

operator → 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-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 opt

dot-operator-head → .

dot-operator-character → . | operator-character

dot-operator-characters → dot-operator-characters opt

binary-operator →

prefix-operator → operator

postfix-operator →

Types

Grammar of a type

type →

type → array-type

type →

type → type-identifier

type →

type → optional-type

type →

type → protocol-composition-type

type →

type → metatype-type

type →

type → self-type

type → ( )

Grammar of a type annotation

type-annotation → : attributes opt inoutopt

Grammar of a type identifier

type-identifier → type-name opt | type-name opt . type-identifier

type-name →

Grammar of a tuple type

tuple-type → ( ) | ( tuple-type-element , )

tuple-type-element-list → tuple-type-element | , tuple-type-element-list

tuple-type-element → type-annotation |

element-name → identifier

Grammar of a function type

function-type → opt function-type-argument-clause throwsopt ->

function-type-argument-clause → ( )

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

function-type-argument-list → | function-type-argument ,

function-type-argument → attributes opt inoutopt | argument-label

argument-label → identifier

Grammar of an array type

array-type → [ ]

Grammar of a dictionary type

dictionary-type → [ type : ]

Grammar of an optional type

optional-type → type ?

Grammar of an implicitly unwrapped optional type

implicitly-unwrapped-optional-type → !

Grammar of a protocol composition type

protocol-composition-type → type-identifier &

protocol-composition-continuation → type-identifier |

Grammar of an opaque type

opaque-type → some type

Grammar of a metatype type

metatype-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-identifier | , type-inheritance-list

Grammar of an expression

expression → opt prefix-expression opt

expression-list → expression | , expression-list

Grammar of a prefix expression

prefix-expression → opt postfix-expression

prefix-expression →

in-out-expression → & identifier

Grammar of a try expression

try-operator → try | try ? | try !

Grammar of a binary expression

binary-expression → prefix-expression

binary-expression → try-operator opt

binary-expression → conditional-operator opt prefix-expression

binary-expression →

binary-expressions → binary-expression opt

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-casting-operator → as type

type-casting-operator → as ?

type-casting-operator → as ! type

Grammar of a primary expression

primary-expression → generic-argument-clause opt

primary-expression →

primary-expression → self-expression

primary-expression →

primary-expression → closure-expression

primary-expression →

primary-expression → tuple-expression

primary-expression →

primary-expression → wildcard-expression

primary-expression →

primary-expression → key-path-string-expression

Grammar of a literal expression

literal-expression →

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

literal-expression → #file | #fileID | #filePath

literal-expression → #line | #column | #function | #dsohandle

array-literal → [ opt ]

array-literal-items → array-literal-item ,opt | , array-literal-items

array-literal-item →

dictionary-literal → [ dictionary-literal-items ] | [ : ]

dictionary-literal-items → ,opt | dictionary-literal-item ,

dictionary-literal-item → expression :

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

playground-literal → #fileLiteral ( resourceName : expression )

playground-literal → #imageLiteral ( resourceName : )

Grammar of a self expression

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

self-method-expression → self .

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

self-initializer-expression → self . init

Grammar of a superclass expression

superclass-expression → | superclass-subscript-expression |

superclass-method-expression → super . identifier

superclass-subscript-expression → super [ ]

superclass-initializer-expression → super . init

Grammar of a closure expression

closure-expression → { closure-signature opt opt }

closure-signature → capture-list opt throwsopt function-result opt in

closure-signature → in

closure-parameter-clause → ( ) | ( closure-parameter-list ) |

closure-parameter-list → closure-parameter | , closure-parameter-list

closure-parameter → type-annotation opt

closure-parameter → type-annotation ...

closure-parameter-name →

capture-list → [ capture-list-items

capture-list-items → | capture-list-item ,

capture-list-item → capture-specifier opt

capture-specifier → weak | unowned | unowned(safe) | unowned(unsafe)

Grammar of a implicit member expression

implicit-member-expression → . identifier

Grammar of a parenthesized expression

parenthesized-expression → ( )

Grammar of a tuple expression

tuple-expression → ( ) | ( tuple-element , )

tuple-element-list → tuple-element | , tuple-element-list

tuple-element → | identifier :

Grammar of a wildcard expression

wildcard-expression → _

Grammar of a key-path expression

key-path-expression → \ type opt .

key-path-components → key-path-component | . key-path-components

key-path-component → key-path-postfixes opt |

key-path-postfixes → key-path-postfix opt

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

Grammar of a selector expression

selector-expression → #selector ( )

selector-expression → #selector ( getter: expression )

selector-expression → #selector ( setter: )

Grammar of a key-path string expression

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

Grammar of a postfix expression

postfix-expression →

postfix-expression → postfix-expression

postfix-expression → function-call-expression

postfix-expression →

postfix-expression → explicit-member-expression

postfix-expression →

postfix-expression → subscript-expression

postfix-expression →

postfix-expression → optional-chaining-expression

Grammar of a function call expression

function-call-expression → function-call-argument-clause

function-call-expression → function-call-argument-clause opt

function-call-argument-clause → ( ) | ( function-call-argument-list )

function-call-argument-list → | function-call-argument ,

function-call-argument → expression | : expression

function-call-argument → | identifier :

trailing-closures → closure-expression opt

labeled-trailing-closures → labeled-trailing-closure opt

labeled-trailing-closure → identifier :

Grammar of an initializer expression

initializer-expression → postfix-expression . init

initializer-expression → . init ( argument-names )

Grammar of an explicit member expression

explicit-member-expression → . decimal-digits

explicit-member-expression → . identifier opt

explicit-member-expression → postfix-expression . ( argument-names )

argument-names → argument-names opt

argument-name → :

Grammar of a postfix self expression

postfix-self-expression → postfix-expression . self

Grammar of a subscript expression

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

Grammar of a forced-value expression

forced-value-expression → !

Grammar of an optional-chaining expression

optional-chaining-expression → postfix-expression ?

Statements

Grammar of a statement

statement → expression ;opt

statement → ;opt

statement → loop-statement ;opt

statement → ;opt

statement → labeled-statement ;opt

statement → ;opt

statement → defer-statement ;opt

statement → ;opt

statement → compiler-control-statement

statements → statements opt

Grammar of a loop statement

loop-statement →

loop-statement → while-statement

loop-statement →

Grammar of a for-in statement

for-in-statement → for caseopt pattern in where-clause opt

Grammar of a while statement

while-statement → while condition-list

condition-list → condition | , condition-list

condition → | availability-condition | | optional-binding-condition

case-condition → case initializer

optional-binding-condition → let initializer | var initializer

Grammar of a repeat-while statement

repeat-while-statement → repeat while expression

Grammar of a branch statement

branch-statement →

branch-statement → guard-statement

branch-statement →

Grammar of an if statement

if-statement → if condition-list else-clause opt

else-clause → else | else if-statement

Grammar of a guard statement

guard-statement → guard else code-block

Grammar of a switch statement

switch-statement → switch { switch-cases opt }

switch-cases → switch-cases opt

switch-case → statements

switch-case →

case-label → attributes opt case :

case-item-list → pattern opt | pattern opt , case-item-list

default-label → opt default :

where-clause → where where-expression

where-expression →

conditional-switch-case → switch-if-directive-clause opt switch-else-directive-clause opt

switch-if-directive-clause → if-directive switch-cases opt

switch-elseif-directive-clauses → switch-elseif-directive-clauses opt

switch-elseif-directive-clause → compilation-condition opt

switch-else-directive-clause → else-directive opt

Grammar of a labeled statement

labeled-statement → statement-label

statement-label → label-name :

label-name →

Grammar of a control transfer statement

control-transfer-statement → break-statement

control-transfer-statement →

control-transfer-statement → fallthrough-statement

control-transfer-statement →

control-transfer-statement → throw-statement

Grammar of a break statement

break-statement → break opt

Grammar of a continue statement

continue-statement → continue label-name opt

Grammar of a fallthrough statement

fallthrough-statement → fallthrough

Grammar of a return statement

return-statement → return opt

Grammar of a throw statement

throw-statement → throw expression

Grammar of a defer statement

defer-statement → defer

Grammar of a do statement

do-statement → do code-block opt

catch-clauses → catch-clause opt

catch-clause → catch catch-pattern-list opt

catch-pattern-list → catch-pattern | , catch-pattern-list

catch-pattern → where-clause opt

Grammar of a compiler control statement

compiler-control-statement →

compiler-control-statement → line-control-statement

compiler-control-statement →

Grammar of a conditional compilation block

conditional-compilation-block → if-directive-clause opt else-directive-clause opt

if-directive-clause → if-directive statements opt

elseif-directive-clauses → elseif-directive-clauses opt

elseif-directive-clause → compilation-condition opt

else-directive-clause → else-directive opt

if-directive → #if

elseif-directive → #elseif

else-directive → #else

endif-directive → #endif

compilation-condition → platform-condition

compilation-condition →

compilation-condition → boolean-literal

compilation-condition → ( )

compilation-condition → ! compilation-condition

compilation-condition → && compilation-condition

compilation-condition → || compilation-condition

platform-condition → os ( )

platform-condition → arch ( architecture )

platform-condition → swift ( >= ) | swift ( < swift-version )

platform-condition → compiler ( >= ) | compiler ( < swift-version )

platform-condition → canImport ( )

platform-condition → targetEnvironment ( environment )

operating-system → macOS | iOS | watchOS | tvOS

architecture → i386 | x86_64 | arm | arm64

swift-version → swift-version-continuation opt

swift-version-continuation → . swift-version-continuation opt

module-name →

environment → simulator | macCatalyst

Grammar of a line control statement

line-control-statement → #sourceLocation ( file: file-path , line: )

line-control-statement → #sourceLocation ( )

line-number → A decimal integer greater than zero

file-path → static-string-literal

Grammar of a compile-time diagnostic statement

diagnostic-statement → #error ( )

diagnostic-statement → #warning ( diagnostic-message )

diagnostic-message →

Grammar of an availability condition

availability-condition → #available ( availability-arguments )

availability-arguments → | availability-argument ,

availability-argument → platform-name

availability-argument → *

platform-name → iOS | iOSApplicationExtension

platform-name → macOS | macOSApplicationExtension

platform-name → macCatalyst | macCatalystApplicationExtension

platform-name → watchOS

platform-name → tvOS

platform-version → decimal-digits

platform-version → . decimal-digits

platform-version → . decimal-digits .

declaration → import-declaration

declaration →

declaration → variable-declaration

declaration →

declaration → function-declaration

declaration →

declaration → struct-declaration

declaration →

declaration → protocol-declaration

declaration →

declaration → deinitializer-declaration

declaration →

declaration → subscript-declaration

declaration →

declaration → precedence-group-declaration

declarations → declarations opt

Grammar of a top-level declaration

top-level-declaration → opt

Grammar of a code block

code-block → { statements opt }

Grammar of an import declaration

import-declaration → opt import import-kind opt

import-path → import-path-identifier | . import-path

import-path-identifier → | operator

Grammar of a constant declaration

constant-declaration → opt declaration-modifiers opt let

pattern-initializer-list → pattern-initializer | , pattern-initializer-list

pattern-initializer → initializer opt

initializer → =

Grammar of a variable declaration

variable-declaration → variable-declaration-head

variable-declaration → variable-declaration-head type-annotation

variable-declaration → variable-declaration-head initializer

variable-declaration → variable-declaration-head type-annotation opt willSet-didSet-block

variable-declaration-head → opt declaration-modifiers opt var

variable-name →

getter-setter-block → code-block

getter-setter-block → { setter-clause opt }

getter-setter-block → { getter-clause }

getter-clause → opt mutation-modifier opt get

setter-clause → attributes opt opt set setter-name opt

setter-name → ( identifier )

getter-setter-keyword-block → { setter-keyword-clause opt }

getter-setter-keyword-block → { getter-keyword-clause }

getter-keyword-clause → opt mutation-modifier opt get

setter-keyword-clause → opt mutation-modifier opt set

willSet-didSet-block → { didSet-clause opt }

willSet-didSet-block → { willSet-clause opt }

willSet-clause → opt willSet setter-name opt

didSet-clause → attributes opt didSet opt code-block

Grammar of a type alias declaration

typealias-declaration → opt access-level-modifier opt typealias generic-parameter-clause opt

typealias-name → identifier

typealias-assignment → =

Grammar of a function declaration

function-declaration → function-head generic-parameter-clause opt generic-where-clause opt opt

function-head → attributes opt opt func

function-name → identifier |

function-signature → parameter-clause throwsopt opt

function-signature → parameter-clause rethrows opt

function-result → -> attributes opt

function-body → code-block

parameter-clause → ( ) | ( )

parameter-list → parameter | , parameter-list

parameter → opt local-parameter-name default-argument-clause opt

parameter → opt local-parameter-name

parameter → external-parameter-name opt type-annotation ...

external-parameter-name →

local-parameter-name → identifier

default-argument-clause → =

Grammar of an enumeration declaration

enum-declaration → attributes opt opt union-style-enum

enum-declaration → opt access-level-modifier opt

union-style-enum → indirectopt enum enum-name opt type-inheritance-clause opt opt { union-style-enum-members opt }

union-style-enum-members → union-style-enum-members opt

union-style-enum-member → | union-style-enum-case-clause |

union-style-enum-case-clause → attributes opt indirectopt case

union-style-enum-case-list → union-style-enum-case | , union-style-enum-case-list

union-style-enum-case → tuple-type opt

enum-name →

enum-case-name → identifier

raw-value-style-enum → enum generic-parameter-clause opt generic-where-clause opt { }

raw-value-style-enum-members → raw-value-style-enum-member opt

raw-value-style-enum-member → declaration | | compiler-control-statement

raw-value-style-enum-case-clause → opt case raw-value-style-enum-case-list

raw-value-style-enum-case-list → | raw-value-style-enum-case ,

raw-value-style-enum-case → enum-case-name opt

raw-value-assignment → = raw-value-literal

raw-value-literal → | static-string-literal |

Grammar of a structure declaration

struct-declaration → attributes opt opt struct struct-name opt type-inheritance-clause opt opt struct-body

struct-name →

struct-body → { struct-members opt }

struct-members → struct-members opt

struct-member → | compiler-control-statement

Grammar of a class declaration

class-declaration → opt access-level-modifier opt finalopt class generic-parameter-clause opt opt generic-where-clause opt

class-declaration → attributes opt final opt class class-name opt type-inheritance-clause opt opt class-body

class-name →

class-body → { class-members opt }

class-members → class-members opt

class-member → | compiler-control-statement

Grammar of a protocol declaration

protocol-declaration → opt access-level-modifier opt protocol type-inheritance-clause opt opt protocol-body

protocol-name →

protocol-body → { protocol-members opt }

protocol-members → protocol-members opt

protocol-member → | compiler-control-statement

protocol-member-declaration →

protocol-member-declaration → protocol-method-declaration

protocol-member-declaration →

protocol-member-declaration → protocol-subscript-declaration

protocol-member-declaration →

protocol-member-declaration → typealias-declaration

Grammar of a protocol property declaration

protocol-property-declaration → variable-name getter-setter-keyword-block

Grammar of a protocol method declaration

protocol-method-declaration → function-name opt function-signature opt

Grammar of a protocol initializer declaration

protocol-initializer-declaration → initializer-head opt parameter-clause throwsopt opt

protocol-initializer-declaration → initializer-head opt parameter-clause rethrows opt

Grammar of a protocol subscript declaration

protocol-subscript-declaration → subscript-head generic-where-clause opt

Grammar of a protocol associated type declaration

protocol-associated-type-declaration → attributes opt opt associatedtype typealias-name opt typealias-assignment opt opt

Grammar of an initializer declaration

initializer-declaration → initializer-head opt parameter-clause throwsopt opt initializer-body

initializer-declaration → generic-parameter-clause opt rethrows generic-where-clause opt

initializer-head → attributes opt opt init

initializer-head → attributes opt opt init ?

initializer-head → attributes opt opt init !

initializer-body → code-block

Grammar of a deinitializer declaration

deinitializer-declaration → opt deinit code-block

Grammar of an extension declaration

extension-declaration → opt access-level-modifier opt extension type-inheritance-clause opt opt extension-body

extension-body → { opt }

extension-members → extension-member opt

extension-member → declaration |

Grammar of a subscript declaration

subscript-declaration → subscript-head generic-where-clause opt

subscript-head → attributes opt opt subscript generic-parameter-clause opt

subscript-result → -> attributes opt

Grammar of an operator declaration

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

prefix-operator-declaration → prefix operator

postfix-operator-declaration → postfix operator operator

infix-operator-declaration → infix operator infix-operator-group opt

infix-operator-group → :

Grammar of a precedence group declaration

precedence-group-declaration → precedencegroup precedence-group-name { opt }

precedence-group-attributes → precedence-group-attribute opt

precedence-group-attribute → precedence-group-relation

precedence-group-attribute →

precedence-group-attribute → precedence-group-associativity

precedence-group-relation → higherThan :

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

precedence-group-assignment → assignment :

precedence-group-associativity → associativity : left

precedence-group-associativity → associativity : right

precedence-group-associativity → associativity : none

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

precedence-group-name →

Grammar of a declaration modifier

declaration-modifier → access-level-modifier

declaration-modifier →

declaration-modifiers → declaration-modifier opt

access-level-modifier → private | private ( set )

access-level-modifier → fileprivate | fileprivate ( set )

access-level-modifier → internal | internal ( set )

access-level-modifier → public | public ( set )

access-level-modifier → open | open ( set )

mutation-modifier → mutating | nonmutating

Attributes

Grammar of an attribute

attribute → @ attribute-argument-clause opt

attribute-name →

attribute-argument-clause → ( balanced-tokens opt )

attributes → attributes opt

balanced-tokens → balanced-tokens opt

balanced-token → ( opt )

balanced-token → [ balanced-tokens opt ]

balanced-token → { opt }

balanced-token → Any identifier, keyword, literal, or operator

balanced-token → Any punctuation except (, ), [, ], {, or }

Grammar of a pattern

pattern → wildcard-pattern opt

pattern → identifier-pattern opt

pattern → value-binding-pattern

pattern → type-annotation opt

pattern →

pattern → optional-pattern

pattern →

pattern → expression-pattern

Grammar of a wildcard pattern

wildcard-pattern → _

Grammar of an identifier pattern

identifier-pattern →

Grammar of a value-binding pattern

value-binding-pattern → var pattern | let

Grammar of a tuple pattern

tuple-pattern → ( tuple-pattern-element-list opt )

tuple-pattern-element-list → | tuple-pattern-element ,

tuple-pattern-element → pattern | : pattern

Grammar of an enumeration case pattern

enum-case-pattern → opt . enum-case-name opt

Grammar of an optional pattern

optional-pattern → identifier-pattern ?

Grammar of a type casting pattern

type-casting-pattern → | as-pattern

is-pattern → is

as-pattern → pattern as

Grammar of an expression pattern

expression-pattern → expression

Generic Parameters and Arguments

Grammar of a generic parameter clause

generic-parameter-clause → < generic-parameter-list >

generic-parameter-list → | generic-parameter ,

generic-parameter → type-name

generic-parameter → : type-identifier

generic-parameter → : protocol-composition-type

generic-where-clause → where

requirement-list → requirement | , requirement-list

requirement → | same-type-requirement

conformance-requirement → : type-identifier

conformance-requirement → : protocol-composition-type

same-type-requirement → == type

Grammar of a generic argument clause

generic-argument-clause → < >

generic-argument-list → generic-argument | , generic-argument-list