Added in API level 29

Summary: Nested Classes | Ctors | Methods | Inherited Methods

Edits

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Kotlin |Java

public final class Edits
extends Object

java.lang.Object
↳	android.icu.text.Edits

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Records lengths of string edits but not replacement text. Supports replacements, insertions, deletions in linear progression. Does not support moving/reordering of text.

There are two types of edits: change edits and no-change edits. Add edits to instances of this class using addReplace(int, int) (for change edits) and addUnchanged(int) (for no-change edits). Change edits are retained with full granularity, whereas adjacent no-change edits are always merged together. In no-change edits, there is a one-to-one mapping between code points in the source and destination strings.

After all edits have been added, instances of this class should be considered immutable, and an Edits.Iterator can be used for queries.

There are four flavors of Edits.Iterator:

• getFineIterator() retains full granularity of change edits.
• getFineChangesIterator() retains full granularity of change edits, and when calling next() on the iterator, skips over no-change edits (unchanged regions).
• getCoarseIterator() treats adjacent change edits as a single edit. (Adjacent no-change edits are automatically merged during the construction phase.)
• getCoarseChangesIterator() treats adjacent change edits as a single edit, and when calling next() on the iterator, skips over no-change edits (unchanged regions).

For example, consider the string "abcßDeF", which case-folds to "abcssdef". This string has the following fine edits:

• abc \u21e8 abc (no-change)
• ß \u21e8 ss (change)
• D \u21e8 d (change)
• e \u21e8 e (no-change)
• F \u21e8 f (change)

and the following coarse edits (note how adjacent change edits get merged together):

• abc \u21e8 abc (no-change)
• ßD \u21e8 ssd (change)
• e \u21e8 e (no-change)
• F \u21e8 f (change)

The "fine changes" and "coarse changes" iterators will step through only the change edits when their Edits.Iterator.next() methods are called. They are identical to the non-change iterators when their Edits.Iterator.findSourceIndex(int) or Edits.Iterator.findDestinationIndex(int) methods are used to walk through the string.

For examples of how to use this class, see the test TestCaseMapEditsIteratorDocs in UCharacterCaseTest.java.

Summary

Nested classes
class	Edits.Iterator Access to the list of edits.

Public constructors
Edits() Constructs an empty object.

Public methods
void	addReplace(int oldLength, int newLength) Adds a change edit: a record for a text replacement/insertion/deletion.
void	addUnchanged(int unchangedLength) Adds a no-change edit: a record for an unchanged segment of text.
Edits.Iterator	getCoarseChangesIterator() Returns an Iterator for coarse-grained change edits (adjacent change edits are treated as one).
Edits.Iterator	getCoarseIterator() Returns an Iterator for coarse-grained change and no-change edits (adjacent change edits are treated as one).
Edits.Iterator	getFineChangesIterator() Returns an Iterator for fine-grained change edits (full granularity of change edits is retained).
Edits.Iterator	getFineIterator() Returns an Iterator for fine-grained change and no-change edits (full granularity of change edits is retained).
boolean	hasChanges()
int	lengthDelta() How much longer is the new text compared with the old text?
Edits	mergeAndAppend(Edits ab, Edits bc) Merges the two input Edits and appends the result to this object.
int	numberOfChanges()
void	reset() Resets the data but may not release memory.

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

Edits

Added in API level 29

public Edits ()

Constructs an empty object.

Public methods

addReplace

Added in API level 29

public void addReplace (int oldLength, 
                int newLength)

Adds a change edit: a record for a text replacement/insertion/deletion. Normally called from inside ICU string transformation functions, not user code.

Parameters
oldLength	int
newLength	int

addUnchanged

Added in API level 29

public void addUnchanged (int unchangedLength)

Adds a no-change edit: a record for an unchanged segment of text. Normally called from inside ICU string transformation functions, not user code.

Parameters
unchangedLength	int

getCoarseChangesIterator

Added in API level 29

public Edits.Iterator getCoarseChangesIterator ()

Returns an Iterator for coarse-grained change edits (adjacent change edits are treated as one). Can be used to perform simple string updates. Skips no-change edits.

Returns
Edits.Iterator	an Iterator that merges adjacent changes.

getCoarseIterator

Added in API level 29

public Edits.Iterator getCoarseIterator ()

Returns an Iterator for coarse-grained change and no-change edits (adjacent change edits are treated as one). Can be used to perform simple string updates. Adjacent change edits are treated as one edit.

Returns
Edits.Iterator	an Iterator that merges adjacent changes.

getFineChangesIterator

Added in API level 29

public Edits.Iterator getFineChangesIterator ()

Returns an Iterator for fine-grained change edits (full granularity of change edits is retained). Can be used for modifying styled text. Skips no-change edits.

Returns
Edits.Iterator	an Iterator that separates adjacent changes.

getFineIterator

Added in API level 29

public Edits.Iterator getFineIterator ()

Returns an Iterator for fine-grained change and no-change edits (full granularity of change edits is retained). Can be used for modifying styled text.

Returns
Edits.Iterator	an Iterator that separates adjacent changes.

hasChanges

Added in API level 29

public boolean hasChanges ()

Returns
boolean	true if there are any change edits

lengthDelta

Added in API level 29

public int lengthDelta ()

How much longer is the new text compared with the old text?

Returns
int	new length minus old length

mergeAndAppend

Added in API level 29

public Edits mergeAndAppend (Edits ab, 
                Edits bc)

Merges the two input Edits and appends the result to this object.

Consider two string transformations (for example, normalization and case mapping) where each records Edits in addition to writing an output string.
Edits ab reflect how substrings of input string a map to substrings of intermediate string b.
Edits bc reflect how substrings of intermediate string b map to substrings of output string c.
This function merges ab and bc such that the additional edits recorded in this object reflect how substrings of input string a map to substrings of output string c.

If unrelated Edits are passed in where the output string of the first has a different length than the input string of the second, then an IllegalArgumentException is thrown.

Parameters
ab	Edits: reflects how substrings of input string a map to substrings of intermediate string b.
bc	Edits: reflects how substrings of intermediate string b map to substrings of output string c.

Returns
Edits	this, with the merged edits appended

numberOfChanges

Added in API level 29

public int numberOfChanges ()

Returns
int	the number of change edits

reset

Added in API level 29

public void reset ()

Resets the data but may not release memory.