Normalizer2

Kotlin |Java

abstract class Normalizer2

kotlin.Any
↳	android.icu.text.Normalizer2

Unicode normalization functionality for standard Unicode normalization or for using custom mapping tables. All instances of this class are unmodifiable/immutable. The Normalizer2 class is not intended for public subclassing.

The primary functions are to produce a normalized string and to detect whether a string is already normalized. The most commonly used normalization forms are those defined in https://www.unicode.org/reports/tr15/ However, this API supports additional normalization forms for specialized purposes. For example, NFKC_Casefold is provided via getInstance("nfkc_cf", COMPOSE) and can be used in implementations of UTS #46.

Not only are the standard compose and decompose modes supplied, but additional modes are provided as documented in the Mode enum.

Some of the functions in this class identify normalization boundaries. At a normalization boundary, the portions of the string before it and starting from it do not interact and can be handled independently.

The spanQuickCheckYes() stops at a normalization boundary. When the goal is a normalized string, then the text before the boundary can be copied, and the remainder can be processed with normalizeSecondAndAppend().

The hasBoundaryBefore(), hasBoundaryAfter() and isInert() functions test whether a character is guaranteed to be at a normalization boundary, regardless of context. This is used for moving from one normalization boundary to the next or preceding boundary, and for performing iterative normalization.

Iterative normalization is useful when only a small portion of a longer string needs to be processed. For example, in ICU, iterative normalization is used by the NormalizationTransliterator (to avoid replacing already-normalized text) and ucol_nextSortKeyPart() (to process only the substring for which sort key bytes are computed).

The set of normalization boundaries returned by these functions may not be complete: There may be more boundaries that could be returned. Different functions may return different boundaries.

Summary

Nested classes
	`Mode` Constants for normalization modes.

Public methods
abstract StringBuilder!	`append(first: StringBuilder!, second: CharSequence!)` Appends the second string to the first string (merging them at the boundary) and returns the first string.
open Int	`composePair(a: Int, b: Int)` Performs pairwise composition of a & b and returns the composite if there is one.
open Int	`getCombiningClass(c: Int)` Gets the combining class of c.
abstract String!	`getDecomposition(c: Int)` Gets the decomposition mapping of c.
open static Normalizer2!	`getInstance(data: InputStream!, name: String!, mode: Normalizer2.Mode!)` Returns a Normalizer2 instance which uses the specified data file (an ICU data file if data=null, or else custom binary data) and which composes or decomposes text according to the specified mode.
open static Normalizer2!	`getNFCInstance()` Returns a Normalizer2 instance for Unicode NFC normalization.
open static Normalizer2!	`getNFDInstance()` Returns a Normalizer2 instance for Unicode NFD normalization.
open static Normalizer2!	`getNFKCCasefoldInstance()` Returns a Normalizer2 instance for Unicode toNFKC_Casefold() normalization which is equivalent to applying the NFKC_Casefold mappings and then NFC.
open static Normalizer2!	`getNFKCInstance()` Returns a Normalizer2 instance for Unicode NFKC normalization.
open static Normalizer2!	`getNFKDInstance()` Returns a Normalizer2 instance for Unicode NFKD normalization.
open String!	`getRawDecomposition(c: Int)` Gets the raw decomposition mapping of c.
abstract Boolean	`hasBoundaryAfter(c: Int)` Tests if the character always has a normalization boundary after it, regardless of context.
abstract Boolean	`hasBoundaryBefore(c: Int)` Tests if the character always has a normalization boundary before it, regardless of context.
abstract Boolean	`isInert(c: Int)` Tests if the character is normalization-inert.
abstract Boolean	`isNormalized(s: CharSequence!)` Tests if the string is normalized.
open String!	`normalize(src: CharSequence!)` Returns the normalized form of the source string.
abstract StringBuilder!	`normalize(src: CharSequence!, dest: StringBuilder!)` Writes the normalized form of the source string to the destination string (replacing its contents) and returns the destination string.
abstract Appendable!	`normalize(src: CharSequence!, dest: Appendable!)` Writes the normalized form of the source string to the destination Appendable and returns the destination Appendable.
abstract StringBuilder!	`normalizeSecondAndAppend(first: StringBuilder!, second: CharSequence!)` Appends the normalized form of the second string to the first string (merging them at the boundary) and returns the first string.
abstract Normalizer.QuickCheckResult!	`quickCheck(s: CharSequence!)` Tests if the string is normalized.
abstract Int	`spanQuickCheckYes(s: CharSequence!)` Returns the end of the normalized substring of the input string.

Parameters
`first`	StringBuilder!: string, should be normalized
`second`	CharSequence!: string, should be normalized

Parameters
`a`	Int: A (normalization starter) code point.
`b`	Int: Another code point.

Parameters
`data`	InputStream!: the binary, big-endian normalization (.nrm file) data, or null for ICU data
`name`	String!: "nfc" or "nfkc" or "nfkc_cf" or "nfkc_scf" or name of custom data file
`mode`	Normalizer2.Mode!: normalization mode (compose or decompose etc.)

Parameters
`src`	CharSequence!: source string
`dest`	StringBuilder!: destination string; its contents is replaced with normalized src

Normalizer2

Summary

Public methods

append

composePair

getCombiningClass

getDecomposition

getInstance

getNFCInstance

getNFDInstance

getNFKCCasefoldInstance

getNFKCInstance

getNFKDInstance

getRawDecomposition

hasBoundaryAfter

hasBoundaryBefore

isInert

isNormalized

normalize

normalize

normalize

normalizeSecondAndAppend

quickCheck

spanQuickCheckYes