The_Swift_Programming_Language
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clause initializer-body
initializer-head → attributes opt convenience opt init initializer-body → code-block
G R A M M A R O F A D E I N I T I A L I Z E R D E C L A R A T I O N
deinitializer-declaration → attributes opt deinit code-block
G R A M M A R O F A N E X T E N S I O N D E C L A R A T I O N
extension-declaration → extension type-identifier type-inheritance- clause opt extension-body
extension-body → { declarations opt }
G R A M M A R O F A S U B S C R I P T D E C L A R A T I O N
subscript-declaration → subscript-head subscript-result code-block subscript-declaration → subscript-head subscript-result getter-setter-block subscript-declaration → subscript-head subscript-result getter-setter-keyword-
block
subscript-head → attributes opt subscript parameter-clause subscript-result → -> type
G R A M M A R O F A N O P E R A T O R D E C L A R A T I O N
operator-declaration → prefix-operator-declaration postfix-operator-declaration infix-operator-declaration
prefix-operator-declaration → operator prefix operator { } postfix-operator-declaration → operator postfix operator { } infix-operator-declaration → operator infix operator { infix-operator-attributes opt }
infix-operator-attributes → precedence-clause opt associativity-clause opt precedence-clause → precedence precedence-level
precedence-level → Digit 0 through 255 associativity-clause → associativity associativity associativity → left right none
Patterns
G R A M M A R O F A P A T T E R N
pattern → wildcard-pattern type-annotationopt pattern → identifier-pattern type-annotationopt pattern → value-binding-pattern
pattern → tuple-pattern type-annotationopt pattern → enum-case-pattern
pattern → type-casting-pattern pattern → expression-pattern
G R A M M A R O F A W I L D C A R D P A T T E R N
wildcard-pattern → _
G R A M M A R O F A N I D E N T I F I E R P A T T E R N
identifier-pattern → identifier
G R A M M A R O F A V A L U E - B I N D I N G P A T T E R N
value-binding-pattern → var pattern let pattern
G R A M M A R O F A T U P L E P A T T E R N
tuple-pattern → ( tuple-pattern-element-list opt )
tuple-pattern-element-list → tuple-pattern-element tuple-pattern-element , tuple- pattern-element-list
tuple-pattern-element → pattern
G R A M M A R O F A N E N U M E R A T I O N C A S E P A T T E R N
enum-case-pattern → type-identifieropt . enum-case-name tuple-patternopt
G R A M M A R O F A T Y P E C A S T I N G P A T T E R N
type-casting-pattern → is-pattern as-pattern is-pattern → is type
as-pattern → pattern as type
G R A M M A R O F A N E X P R E S S I O N P A T T E R N
expression-pattern → expression
Attributes
G R A M M A R O F A N A T T R I B U T E
attribute → @ attribute-name attribute-argument-clause opt attribute-name → identifier
attribute-argument-clause → ) attributes → attribute attributes opt
primary-expression → closure-expression primary-expression → parenthesized-expression primary-expression → implicit-member-expression primary-expression → wildcard-expression
G R A M M A R O F A L I T E R A L E X P R E S S I O N
literal-expression → literal
literal-expression → array-literal dictionary-literal
literal-expression → __FILE__ __LINE__ __COLUMN__ __FUNCTION__
array-literal → [ array-literal-items opt ]
array-literal-items → array-literal-item , opt 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
G R A M M A R O F A S E L F E X P R E S S I O N
self-expression → self self-expression → self . identifier self-expression → self [ expression ] self-expression → self . init
G R A M M A R O F A S U P E R C L A S S E X P R E S S I O N
superclass-expression → superclass-method-expression superclass-subscript- expression superclass-initializer-expression
superclass-method-expression → super . identifier superclass-subscript-expression → expression ] superclass-initializer-expression →
G R A M M A R O F A C L O S U R E E X P R E S S I O N
closure-expression → { closure-signature opt statements }
closure-signature → parameter-clause function-result opt in closure-signature → identifier-list function-result opt in closure-signature → capture-list parameter-clause function-result opt in closure-signature → capture-list identifier-list function-result opt in closure-signature → capture-list in
capture-list → [ capture-specifier expression ]
postfix-self-expression → postfix-expression . self
G R A M M A R O F A D Y N A M I C T Y P E E X P R E S S I O N
dynamic-type-expression → postfix-expression . dynamicType
G R A M M A R O F A S U B S C R I P T E X P R E S S I O N
subscript-expression → postfix-expression [ expression-list ]
G R A M M A R O F A F O R C E D - V A L U E E X P R E S S I O N
forced-value-expression → postfix-expression !
G R A M M A R O F A N O P T I O N A L- C H A I N I N G E X P R E S S I O N
optional-chaining-expression → postfix-expression ?
Lexical Structure
G R A M M A R O F A N I D E N T I F I E R
identifier → identifier-head identifier-characters opt identifier → ` identifier-head identifier-characters opt ` identifier → implicit-parameter-name
identifier-list → identifier identifier , identifier-list
identifier-head → Upperor lowercase letter A through Z
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 opt
implicit-parameter-name → $ decimal-digits
G R A M M A R O F A L I T E R A L
literal → integer-literal floating-point-literal string-literal
G R A M M A R O F A N I N T E G E R L I T E R A L
integer-literal → binary-literal integer-literal → octal-literal integer-literal → decimal-literal integer-literal → hexadecimal-literal
binary-literal → 0b binary-digit binary-literal-characters opt binary-digit → Digit 0 or 1
binary-literal-character → binary-digit _
binary-literal-characters → binary-literal-character binary-literal-characters opt
octal-literal → 0o octal-digit octal-literal-characters opt octal-digit → Digit 0 through 7
octal-literal-character → octal-digit _
octal-literal-characters → octal-literal-character octal-literal-characters opt
decimal-literal → decimal-digit decimal-literal-characters opt decimal-digit → Digit 0 through 9
decimal-digits → decimal-digit decimal-digits opt decimal-literal-character → decimal-digit _
decimal-literal-characters → decimal-literal-character decimal-literal-characters opt
hexadecimal-literal → 0x hexadecimal-digit hexadecimal-literal-characters opt 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 opt
G R A M M A R O F A F L O A T I N G - P O I N T L I T E R A L
floating-point-literal → decimal-literal decimal-fractionopt decimal-exponent opt floating-point-literal → hexadecimal-literal hexadecimal-fractionopt hexadecimal-
exponent
decimal-fraction → . decimal-literal
decimal-exponent → floating-point-e signopt decimal-literal
hexadecimal-fraction → . hexadecimal-literal opt hexadecimal-exponent → floating-point-p signopt hexadecimal-literal
floating-point-e → e E floating-point-p → p P sign → + -
G R A M M A R O F A S T R I N G L I T E R A L
string-literal → " quoted-text "
quoted-text → quoted-text-item quoted-text opt quoted-text-item → escaped-character quoted-text-item → \( expression )
quoted-text-item → Any Unicode extended grapheme cluster except " , \ , U+000A, or U+000D
escaped-character → \0 \\ \t \n \r \" \' escaped-character → \x hexadecimal-digit hexadecimal-digit
escaped-character → \u hexadecimal-digit hexadecimal-digit hexadecimaldigit hexadecimal-digit
escaped-character → \U hexadecimal-digit hexadecimal-digit hexadecimaldigit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimaldigit hexadecimal-digit
G R A M M A R O F O P E R A T O R S
operator → operator-character operatoropt operator-character → / = - + ! * % < > & | ^ ~ .
binary-operator → operator prefix-operator → operator postfix-operator → operator
Types
G R A M M A R O F A T Y P E
type → array-type function-type type-identifier tuple-type optional-type implicitly-unwrapped-optional-type protocol-composition-type metatype-type
G R A M M A R O F A T Y P E A N N O T A T I O N
type-annotation → : attributes opt type
G R A M M A R O F A T Y P E I D E N T I F I E R
type-identifier → type-name generic-argument-clause opt type-name generic- argument-clause opt . type-identifier
type-name → identifier
G R A M M A R O F A T U P L E T Y P E
tuple-type → ( tuple-type-body opt ) tuple-type-body → tuple-type-element-list ... opt
tuple-type-element-list → tuple-type-element tuple-type-element , tuple-type- element-list
tuple-type-element → attributes opt inout opt type inout opt element-name typeannotation
element-name → identifier
G R A M M A R O F A F U N C T I O N T Y P E
function-type → type -> type
G R A M M A R O F A N A R R A Y T Y P E
array-type → type [ ] array-type [ ]
G R A M M A R O F A N O P T I O N A L T Y P E
optional-type → type ?
G R A M M A R O F A N I M P L I C I T LY U N W R A P P E D O P T I O N A L T Y P E
implicitly-unwrapped-optional-type → type !
G R A M M A R O F A P R O T O C O L C O M P O S I T I O N T Y P E
protocol-composition-type → protocol < protocol-identifier-list opt > protocol-identifier-list → protocol-identifier protocol-identifier , protocol-identifier-
list
protocol-identifier → type-identifier
G R A M M A R O F A M E T A T Y P E T Y P E
metatype-type → type . Type type . Protocol
G R A M M A R O F A T Y P E I N H E R I T A N C E C L A U S E
type-inheritance-clause → : type-inheritance-list
type-inheritance-list → type-identifier type-identifier , type-inheritance-list