swift.grammer

// Statements

// GRAMMAR OF A STATEMENT

statement : expression
statement : declaration
statement : loop-statement
statement : branch-statement
statement : labeled-statement
statement : control-transfer-statement
statements : statement­statements

// GRAMMAR OF A LOOP STATEMENT

loop-statement → for-statement
loop-statement → for-in-statement
loop-statement → while-statement
loop-statement → do-while-statement

// GRAMMAR OF A FOR STATEMENT

for-statement → for­for-init­opt­;­expression­opt­;­expression­opt­code-block­
for-statement → for­(­for-init­opt­;­expression­opt­;­expression­opt­)­code-block­
for-init → variable-declaration­  expression-list­
GRAMMAR OF A FOR-IN STATEMENT

for-in-statement → for­pattern­in­expression­code-block­
GRAMMAR OF A WHILE STATEMENT

while-statement → while­while-condition­code-block­
while-condition → expression­  declaration­
GRAMMAR OF A DO-WHILE STATEMENT

do-while-statement → do­code-block­while­while-condition­
GRAMMAR OF A BRANCH STATEMENT

branch-statement → if-statement­
branch-statement → switch-statement­
GRAMMAR OF AN IF STATEMENT

if-statement → if­if-condition­code-block­else-clause­opt­
if-condition → expression­  declaration­
else-clause → else­code-block­  else­if-statement­
GRAMMAR OF A SWITCH STATEMENT

switch-statement → switch­expression­{­switch-cases­opt­}­
switch-cases → switch-case­switch-cases­opt­
switch-case → case-label­statements­  default-label­statements­
switch-case → case-label­;­  default-label­;­
case-label → case­case-item-list­:­
case-item-list → pattern­guard-clause­opt­  pattern­guard-clause­opt­,­case-item-list­
default-label → default­:­
guard-clause → where­guard-expression­
guard-expression → expression­
GRAMMAR OF A LABELED STATEMENT

labeled-statement → statement-label­loop-statement­  statement-label­switch-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
GRAMMAR OF A BREAK STATEMENT

break-statement → break­label-name­opt­
GRAMMAR OF A CONTINUE STATEMENT

continue-statement → continue­label-name­opt­
GRAMMAR OF A FALLTHROUGH STATEMENT

fallthrough-statement → fallthrough­
GRAMMAR OF A RETURN STATEMENT

return-statement → return­expression­opt­
Generic Parameters and Arguments

GRAMMAR OF A GENERIC PARAMETER CLAUSE

generic-parameter-clause → <­generic-parameter-list­requirement-clause­opt­>­
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
requirement-clause → where­requirement-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-identifier­
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
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 → protocol-declaration­
declaration → initializer-declaration­
declaration → deinitializer-declaration­
declaration → extension-declaration­
declaration → subscript-declaration­
declaration → operator-declaration­
declarations → declaration­declarations­opt­
declaration-specifiers → declaration-specifier­declaration-specifiers­opt­
declaration-specifier → class­  mutating­  nonmutating­  override­  static­  unowned­ unowned(safe)­  unowned(unsafe)­  weak­
GRAMMAR OF A TOP-LEVEL DECLARATION

top-level-declaration → statements­opt­
GRAMMAR OF A CODE BLOCK

code-block → {­statements­opt­}­
GRAMMAR OF AN IMPORT DECLARATION

import-declaration → attributes­opt­import­import-kind­opt­import-path­
import-kind → typealias­  struct­  class­  enum­  protocol­  var­  func­
import-path → import-path-identifier­  import-path-identifier­.­import-path­
import-path-identifier → identifier­  operator­
GRAMMAR OF A CONSTANT DECLARATION

constant-declaration → attributes­opt­declaration-specifiers­opt­let­pattern-initializer-list­
pattern-initializer-list → pattern-initializer­  pattern-initializer­,­pattern-initializer-list­
pattern-initializer → pattern­initializer­opt­
initializer → =­expression­
GRAMMAR OF A VARIABLE DECLARATION

variable-declaration → variable-declaration-head­pattern-initializer-list­
variable-declaration → variable-declaration-head­variable-name­type-annotation­code-block­
variable-declaration → variable-declaration-head­variable-name­type-annotation­getter-setter-block­
variable-declaration → variable-declaration-head­variable-name­type-annotation­getter-setter-keyword-block­
variable-declaration → variable-declaration-head­variable-name­type-annotation­initializer­opt­willSet-didSet-block­
variable-declaration-head → attributes­opt­declaration-specifiers­opt­var­
variable-name → identifier­
getter-setter-block → {­getter-clause­setter-clause­opt­}­
getter-setter-block → {­setter-clause­getter-clause­}­
getter-clause → attributes­opt­get­code-block­
setter-clause → attributes­opt­set­setter-name­opt­code-block­
setter-name → (­identifier­)­
getter-setter-keyword-block → {­getter-keyword-clause­setter-keyword-clause­opt­}­
getter-setter-keyword-block → {­setter-keyword-clause­getter-keyword-clause­}­
getter-keyword-clause → attributes­opt­get­
setter-keyword-clause → attributes­opt­set­
willSet-didSet-block → {­willSet-clause­didSet-clause­opt­}­
willSet-didSet-block → {­didSet-clause­willSet-clause­}­
willSet-clause → attributes­opt­willSet­setter-name­opt­code-block­
didSet-clause → attributes­opt­didSet­setter-name­opt­code-block­
GRAMMAR OF A TYPE ALIAS DECLARATION

typealias-declaration → typealias-head­typealias-assignment­
typealias-head → typealias­typealias-name­
typealias-name → identifier­
typealias-assignment → =­type­
GRAMMAR OF A FUNCTION DECLARATION

function-declaration → function-head­function-name­generic-parameter-clause­opt­function-signature­function-body­
function-head → attributes­opt­declaration-specifiers­opt­func­
function-name → identifier­  operator­
function-signature → parameter-clauses­function-result­opt­
function-result → ->­attributes­opt­type­
function-body → code-block­
parameter-clauses → parameter-clause­parameter-clauses­opt­
parameter-clause → (­)­  (­parameter-list­...­opt­)­
parameter-list → parameter­  parameter­,­parameter-list­
parameter → inout­opt­let­opt­#­opt­parameter-name­local-parameter-name­opt­type-annotation­default-argument-clause­opt­
parameter → inout­opt­var­#­opt­parameter-name­local-parameter-name­opt­type-annotation­default-argument-clause­opt­
parameter → attributes­opt­type­
parameter-name → identifier­  _­
local-parameter-name → identifier­  _­
default-argument-clause → =­expression­
GRAMMAR OF AN ENUMERATION DECLARATION

enum-declaration → attributes­opt­union-style-enum­  attributes­opt­raw-value-style-enum­
union-style-enum → enum-name­generic-parameter-clause­opt­{­union-style-enum-members­opt­}­
union-style-enum-members → union-style-enum-member­union-style-enum-members­opt­
union-style-enum-member → declaration­  union-style-enum-case-clause­
union-style-enum-case-clause → attributes­opt­case­union-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-name­tuple-type­opt­
enum-name → identifier­
enum-case-name → identifier­
raw-value-style-enum → enum-name­generic-parameter-clause­opt­:­type-identifier­{­raw-value-style-enum-members­opt­}­
raw-value-style-enum-members → raw-value-style-enum-member­raw-value-style-enum-members­opt­
raw-value-style-enum-member → declaration­  raw-value-style-enum-case-clause­
raw-value-style-enum-case-clause → attributes­opt­case­raw-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-name­raw-value-assignment­opt­
raw-value-assignment → =­literal­
GRAMMAR OF A STRUCTURE DECLARATION

struct-declaration → attributes­opt­struct­struct-name­generic-parameter-clause­opt­type-inheritance-clause­opt­struct-body­
struct-name → identifier­
struct-body → {­declarations­opt­}­
GRAMMAR OF A CLASS DECLARATION

class-declaration → attributes­opt­class­class-name­generic-parameter-clause­opt­type-inheritance-clause­opt­class-body­
class-name → identifier­
class-body → {­declarations­opt­}­
GRAMMAR OF A PROTOCOL DECLARATION

protocol-declaration → attributes­opt­protocol­protocol-name­type-inheritance-clause­opt­protocol-body­
protocol-name → identifier­
protocol-body → {­protocol-member-declarations­opt­}­
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-declarations → protocol-member-declaration­protocol-member-declarations­opt­
GRAMMAR OF A PROTOCOL PROPERTY DECLARATION

protocol-property-declaration → variable-declaration-head­variable-name­type-annotation­getter-setter-keyword-block­
GRAMMAR OF A PROTOCOL METHOD DECLARATION

protocol-method-declaration → function-head­function-name­generic-parameter-clause­opt­function-signature­
GRAMMAR OF A PROTOCOL INITIALIZER DECLARATION

protocol-initializer-declaration → initializer-head­generic-parameter-clause­opt­parameter-clause­
GRAMMAR OF A PROTOCOL SUBSCRIPT DECLARATION

protocol-subscript-declaration → subscript-head­subscript-result­getter-setter-keyword-block­
GRAMMAR OF A PROTOCOL ASSOCIATED TYPE DECLARATION

protocol-associated-type-declaration → typealias-head­type-inheritance-clause­opt­typealias-assignment­opt­
GRAMMAR OF AN INITIALIZER DECLARATION

initializer-declaration → initializer-head­generic-parameter-clause­opt­parameter-clause­initializer-body­
initializer-head → attributes­opt­convenience­opt­init­
initializer-body → code-block­
GRAMMAR OF A DEINITIALIZER DECLARATION

deinitializer-declaration → attributes­opt­deinit­code-block­
GRAMMAR OF AN EXTENSION DECLARATION

extension-declaration → extension­type-identifier­type-inheritance-clause­opt­extension-body­
extension-body → {­declarations­opt­}­
GRAMMAR OF A SUBSCRIPT DECLARATION

subscript-declaration → subscript-head­subscript-result­code-block­
subscript-declaration → subscript-head­subscript-result­getter-setter-block­
subscript-declaration → subscript-head­subscript-result­getter-setter-keyword-block­
subscript-head → attributes­opt­subscript­parameter-clause­
subscript-result → ->­attributes­opt­type­
GRAMMAR OF AN OPERATOR DECLARATION

operator-declaration → prefix-operator-declaration­  postfix-operator-declaration­  infix-operator-declaration­
prefix-operator-declaration → operator­prefix­operator­{­}­
postfix-operator-declaration → operator­postfix­operator­{­}­
infix-operator-declaration → operator­infix­operator­{­infix-operator-attributes­opt­}­
infix-operator-attributes → precedence-clause­opt­associativity-clause­opt­
precedence-clause → precedence­precedence-level­
precedence-level → Digit 0 through 255
associativity-clause → associativity­associativity­
associativity → left­  right­  none­
Patterns

GRAMMAR OF A PATTERN

pattern → wildcard-pattern­type-annotation­opt­
pattern → identifier-pattern­type-annotation­opt­
pattern → value-binding-pattern­
pattern → tuple-pattern­type-annotation­opt­
pattern → enum-case-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 → var­pattern­  let­pattern­
GRAMMAR OF A TUPLE PATTERN

tuple-pattern → (­tuple-pattern-element-list­opt­)­
tuple-pattern-element-list → tuple-pattern-element­  tuple-pattern-element­,­tuple-pattern-element-list­
tuple-pattern-element → pattern­
GRAMMAR OF AN ENUMERATION CASE PATTERN

enum-case-pattern → type-identifier­opt­.­enum-case-name­tuple-pattern­opt­
GRAMMAR OF A TYPE CASTING PATTERN

type-casting-pattern → is-pattern­  as-pattern­
is-pattern → is­type­
as-pattern → pattern­as­type­
GRAMMAR OF AN EXPRESSION PATTERN

expression-pattern → expression­
Attributes

GRAMMAR OF AN ATTRIBUTE

attribute → @­attribute-name­attribute-argument-clause­opt­
attribute-name → identifier­
attribute-argument-clause → (­balanced-tokens­opt­)­
attributes → attribute­attributes­opt­
balanced-tokens → balanced-token­balanced-tokens­opt­
balanced-token → (­balanced-tokens­opt­)­
balanced-token → [­balanced-tokens­opt­]­
balanced-token → {­balanced-tokens­opt­}­
balanced-token → Any identifier, keyword, literal, or operator
balanced-token → Any punctuation except (­, )­, [­, ]­, {­, or }­
Expressions

GRAMMAR OF AN EXPRESSION

expression → prefix-expression­binary-expressions­opt­
expression-list → expression­  expression­,­expression-list­
GRAMMAR OF A PREFIX EXPRESSION

prefix-expression → prefix-operator­opt­postfix-expression­
prefix-expression → in-out-expression­
in-out-expression → &­identifier­
GRAMMAR OF A BINARY EXPRESSION

binary-expression → binary-operator­prefix-expression­
binary-expression → assignment-operator­prefix-expression­
binary-expression → conditional-operator­prefix-expression­
binary-expression → type-casting-operator­
binary-expressions → binary-expression­binary-expressions­opt­
GRAMMAR OF AN ASSIGNMENT OPERATOR

assignment-operator → =­
GRAMMAR OF A CONDITIONAL OPERATOR

conditional-operator → ?­expression­:­
GRAMMAR OF A TYPE-CASTING OPERATOR

type-casting-operator → is­type­  as­?­opt­type­
GRAMMAR OF A PRIMARY EXPRESSION

primary-expression → identifier­generic-argument-clause­opt­
primary-expression → literal-expression­
primary-expression → self-expression­
primary-expression → superclass-expression­
primary-expression → closure-expression­
primary-expression → parenthesized-expression­
primary-expression → implicit-member-expression­
primary-expression → wildcard-expression­
GRAMMAR OF A LITERAL EXPRESSION

literal-expression → literal­
literal-expression → array-literal­  dictionary-literal­
literal-expression → __FILE__­  __LINE__­  __COLUMN__­  __FUNCTION__­
array-literal → [­array-literal-items­opt­]­
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,­opt­  dictionary-literal-item­,­dictionary-literal-items­
dictionary-literal-item → expression­:­expression­
GRAMMAR OF A SELF EXPRESSION

self-expression → self­
self-expression → self­.­identifier­
self-expression → self­[­expression­]­
self-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[­expression­]­
superclass-initializer-expression → super­.­init­
GRAMMAR OF A CLOSURE EXPRESSION

closure-expression → {­closure-signature­opt­statements­}­
closure-signature → parameter-clause­function-result­opt­in­
closure-signature → identifier-list­function-result­opt­in­
closure-signature → capture-list­parameter-clause­function-result­opt­in­
closure-signature → capture-list­identifier-list­function-result­opt­in­
closure-signature → capture-list­in­
capture-list → [­capture-specifier­expression­]­
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 → (­expression-element-list­opt­)­
expression-element-list → expression-element­  expression-element­,­expression-element-list­
expression-element → expression­  identifier­:­expression­
GRAMMAR OF A WILDCARD EXPRESSION

wildcard-expression → _­
GRAMMAR OF A POSTFIX EXPRESSION

postfix-expression → primary-expression­
postfix-expression → postfix-expression­postfix-operator­
postfix-expression → function-call-expression­
postfix-expression → initializer-expression­
postfix-expression → explicit-member-expression­
postfix-expression → postfix-self-expression­
postfix-expression → dynamic-type-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-expression­parenthesized-expression­
function-call-expression → postfix-expression­parenthesized-expression­opt­trailing-closure­
trailing-closure → closure-expression­
GRAMMAR OF AN INITIALIZER EXPRESSION

initializer-expression → postfix-expression­.­init­
GRAMMAR OF AN EXPLICIT MEMBER EXPRESSION

explicit-member-expression → postfix-expression­.­decimal-digit­
explicit-member-expression → postfix-expression­.­identifier­generic-argument-clause­opt­
GRAMMAR OF A SELF EXPRESSION

postfix-self-expression → postfix-expression­.­self­
GRAMMAR OF A DYNAMIC TYPE EXPRESSION

dynamic-type-expression → postfix-expression­.­dynamicType­
GRAMMAR OF A SUBSCRIPT EXPRESSION

subscript-expression → postfix-expression­[­expression-list­]­
GRAMMAR OF A FORCED-VALUE EXPRESSION

forced-value-expression → postfix-expression­!­
GRAMMAR OF AN OPTIONAL-CHAINING EXPRESSION

optional-chaining-expression → postfix-expression­?­
Lexical Structure

GRAMMAR OF AN IDENTIFIER

identifier → identifier-head­identifier-characters­opt­
identifier → `­identifier-head­identifier-characters­opt­`­
identifier → implicit-parameter-name­
identifier-list → identifier­  identifier­,­identifier-list­
identifier-head → Upper- or 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-character­identifier-characters­opt­
implicit-parameter-name → $­decimal-digits­
GRAMMAR OF A LITERAL

literal → integer-literal­  floating-point-literal­  string-literal­
GRAMMAR OF AN INTEGER LITERAL

integer-literal → binary-literal­
integer-literal → octal-literal­
integer-literal → decimal-literal­
integer-literal → hexadecimal-literal­
binary-literal → 0b­binary-digit­binary-literal-characters­opt­
binary-digit → Digit 0 or 1
binary-literal-character → binary-digit­  _­
binary-literal-characters → binary-literal-character­binary-literal-characters­opt­
octal-literal → 0o­octal-digit­octal-literal-characters­opt­
octal-digit → Digit 0 through 7
octal-literal-character → octal-digit­  _­
octal-literal-characters → octal-literal-character­octal-literal-characters­opt­
decimal-literal → decimal-digit­decimal-literal-characters­opt­
decimal-digit → Digit 0 through 9
decimal-digits → decimal-digit­decimal-digits­opt­
decimal-literal-character → decimal-digit­  _­
decimal-literal-characters → decimal-literal-character­decimal-literal-characters­opt­
hexadecimal-literal → 0x­hexadecimal-digit­hexadecimal-literal-characters­opt­
hexadecimal-digit → Digit 0 through 9, a through f, or A through F
hexadecimal-literal-character → hexadecimal-digit­  _­
hexadecimal-literal-characters → hexadecimal-literal-character­hexadecimal-literal-characters­opt­
GRAMMAR OF A FLOATING-POINT LITERAL

floating-point-literal → decimal-literal­decimal-fraction­opt­decimal-exponent­opt­
floating-point-literal → hexadecimal-literal­hexadecimal-fraction­opt­hexadecimal-exponent­
decimal-fraction → .­decimal-literal­
decimal-exponent → floating-point-e­sign­opt­decimal-literal­
hexadecimal-fraction → .­hexadecimal-literal­opt­
hexadecimal-exponent → floating-point-p­sign­opt­hexadecimal-literal­
floating-point-e → e­  E­
floating-point-p → p­  P­
sign → +­  -­
GRAMMAR OF A STRING LITERAL

string-literal → "­quoted-text­"­
quoted-text → quoted-text-item­quoted-text­opt­
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 → \x­hexadecimal-digit­hexadecimal-digit­
escaped-character → \u­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­
escaped-character → \U­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­hexadecimal-digit­
GRAMMAR OF OPERATORS

operator → operator-character­operator­opt­
operator-character → /­  =­  -­  +­  !­  *­  %­  <­  >­  &­  |­  ^­  ~­  .­
binary-operator → operator­
prefix-operator → operator­
postfix-operator → operator­
Types

GRAMMAR OF A TYPE

type → array-type­  function-type­  type-identifier­  tuple-type­  optional-type­  implicitly-unwrapped-optional-type­  protocol-composition-type­  metatype-type­
GRAMMAR OF A TYPE ANNOTATION

type-annotation → :­attributes­opt­type­
GRAMMAR OF A TYPE IDENTIFIER

type-identifier → type-name­generic-argument-clause­opt­  type-name­generic-argument-clause­opt­.­type-identifier­
type-name → identifier­
GRAMMAR OF A TUPLE TYPE

tuple-type → (­tuple-type-body­opt­)­
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 → attributes­opt­inout­opt­type­  inout­opt­element-name­type-annotation­
element-name → identifier­
GRAMMAR OF A FUNCTION TYPE

function-type → type­->­type­
GRAMMAR OF AN ARRAY TYPE

array-type → type­[­]­  array-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 → protocol­<­protocol-identifier-list­opt­>­
protocol-identifier-list → protocol-identifier­  protocol-identifier­,­protocol-identifier-list­
protocol-identifier → type-identifier­
GRAMMAR OF A METATYPE TYPE

metatype-type → type­.­Type­  type­.­Protocol­
GRAMMAR OF A TYPE INHERITANCE CLAUSE

type-inheritance-clause → :­type-inheritance-list­
type-inheritance-list → type-identifier­  type-identifier­,­type-inheritance-list­
Generic Parameters and Arguments