ICU 76.1: icu::message2::data_model::Key Class Reference

ICU 76.1 76.1

Public Member Functions | Friends
icu::message2::data_model::Key Class Reference

The `Key` class corresponds to the `key` nonterminal in the MessageFormat 2 grammar, https://github.com/unicode-org/message-format-wg/blob/main/spec/message.abnf . More...

`#include <messageformat2_data_model.h>`

Inheritance diagram for icu::message2::data_model::Key:

## Public Member Functions
UBool | isWildcard () const
| Determines if this is a wildcard key.
const Literal & | asLiteral () const
| Returns the contents of this key as a literal.
| Key (const Key &other)
| Copy constructor.
| Key ()
| Wildcard constructor; constructs a Key representing the catchall or wildcard key, '*'.
| Key (const Literal &lit)
| Literal key constructor.
Key & | operator= (Key) noexcept
| Assignment operator.
bool | operator< (const Key &other) const
| Less than operator.
bool | operator== (const Key &other) const
| Equality operator.
virtual | ~Key ()
| Destructor.
Public Member Functions inherited from icu::UObject
virtual | ~UObject ()
| Destructor.
virtual UClassID | getDynamicClassID () const
| ICU4C "poor man's RTTI", returns a UClassID for the actual ICU class.

## Friends
void | swap (Key &k1, Key &k2) noexcept
| Non-member swap function.

## Detailed Description

The `Key` class corresponds to the `key` nonterminal in the MessageFormat 2 grammar, https://github.com/unicode-org/message-format-wg/blob/main/spec/message.abnf .

It also corresponds to the `Literal | CatchallKey` that is the element type of the `keys` array in the `Variant` interface defined in https://github.com/unicode-org/message-format-wg/blob/main/spec/data-model.md#messages

A key is either a literal or the wildcard symbol (represented in messages as '*')

`Key` is immutable, copyable and movable.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

Definition at line 385 of file messageformat2_data_model.h.

## Constructor & Destructor Documentation

## ◆ Key() [1/3]

icu::message2::data_model::Key::Key | ( | const Key & | other | ) |
| inline

Copy constructor.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

Definition at line 412 of file messageformat2_data_model.h.

## ◆ Key() [2/3]

icu::message2::data_model::Key::Key | ( |  | ) |
| inline

Wildcard constructor; constructs a Key representing the catchall or wildcard key, '*'.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

Definition at line 420 of file messageformat2_data_model.h.

## ◆ Key() [3/3]

icu::message2::data_model::Key::Key | ( | const Literal & | lit | ) |
| inlineexplicit

Literal key constructor.

Parameters

  lit | A Literal to use for this key. The result matches the literal `lit`.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

Definition at line 430 of file messageformat2_data_model.h.

## ◆ ~Key()

virtual icu::message2::data_model::Key::~Key | ( |  | ) |
| virtual

Destructor.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

## Member Function Documentation

## ◆ asLiteral()

const Literal & icu::message2::data_model::Key::asLiteral | ( |  | ) | const

Returns the contents of this key as a literal.

Precondition: !isWildcard()

Returns
  The literal contents of the key

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

## ◆ isWildcard()

UBool icu::message2::data_model::Key::isWildcard | ( |  | ) | const
| inline

Determines if this is a wildcard key.

Returns
  True if and only if this is the wildcard key

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

Definition at line 395 of file messageformat2_data_model.h.

## ◆ operator<()

bool icu::message2::data_model::Key::operator< | ( | const Key & | other | ) | const

Less than operator.

Compares the literal of `this` with the literal of `other`. This method is used in representing the mapping from key lists to patterns in a message with variants, and is not expected to be useful otherwise.

Parameters

  other | The Key to compare to this one.

Returns
  true if the two `Key`s are not wildcards and if `this.asLiteral()` < `other.asLiteral()`. Returns false otherwise.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

## ◆ operator=()

Key & icu::message2::data_model::Key::operator= | ( | Key |  | ) |
| noexcept

Assignment operator.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

## ◆ operator==()

bool icu::message2::data_model::Key::operator== | ( | const Key & | other | ) | const

Equality operator.

Compares the literal of `this` with the literal of `other`. This method is used in representing the mapping from key lists to patterns in a message with variants, and is not expected to be useful otherwise.

Parameters

  other | The Key to compare to this one.

Returns
  true if either both `Key`s are wildcards, or `this.asLiteral()` == `other.asLiteral()`. Returns false otherwise.

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

## Friends And Related Symbol Documentation

## ◆ swap

void swap | ( | Key & | k1,
|  | Key & | k2 )
| friend

Non-member swap function.

Parameters

  k1 | will get k2's contents
  k2 | will get k1's contents

Internal
  Do not use. This API is for internal use only. ICU 75 technology preview

Deprecated
  This API is for technology preview only.

Definition at line 439 of file messageformat2_data_model.h.

The documentation for this class was generated from the following file:

- i18n/unicode/messageformat2_data_model.h