Transliterator.java
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 1996-2016, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.text;
import com.ibm.icu.impl.ICUData;
import com.ibm.icu.impl.ICUResourceBundle;
import com.ibm.icu.impl.Utility;
import com.ibm.icu.impl.UtilityExtensions;
import com.ibm.icu.text.RuleBasedTransliterator.Data;
import com.ibm.icu.text.TransliteratorIDParser.SingleID;
import com.ibm.icu.util.CaseInsensitiveString;
import com.ibm.icu.util.ULocale;
import com.ibm.icu.util.ULocale.Category;
import com.ibm.icu.util.UResourceBundle;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.Objects;
import java.util.function.Supplier;
/**
* <code>Transliterator</code> is an abstract class that transliterates text from one format to
* another. The most common kind of transliterator is a script, or alphabet, transliterator. For
* example, a Russian to Latin transliterator changes Russian text written in Cyrillic characters to
* phonetically equivalent Latin characters. It does not <em>translate</em> Russian to English!
* Transliteration, unlike translation, operates on characters, without reference to the meanings of
* words and sentences.
*
* <p>Although script conversion is its most common use, a transliterator can actually perform a
* more general class of tasks. In fact, <code>Transliterator</code> defines a very general API
* which specifies only that a segment of the input text is replaced by new text. The particulars of
* this conversion are determined entirely by subclasses of <code>Transliterator</code>.
*
* <p><b>Transliterators are stateless</b>
*
* <p><code>Transliterator</code> objects are <em>stateless</em>; they retain no information between
* calls to <code>transliterate()</code>. As a result, threads may share transliterators without
* synchronizing them. This might seem to limit the complexity of the transliteration operation. In
* practice, subclasses perform complex transliterations by delaying the replacement of text until
* it is known that no other replacements are possible. In other words, although the <code>
* Transliterator</code> objects are stateless, the source text itself embodies all the needed
* information, and delayed operation allows arbitrary complexity.
*
* <p><b>Batch transliteration</b>
*
* <p>The simplest way to perform transliteration is all at once, on a string of existing text. This
* is referred to as <em>batch</em> transliteration. For example, given a string <code>input</code>
* and a transliterator <code>t</code>, the call
*
* <blockquote>
*
* <code>String result = t.transliterate(input);
* </code>
*
* </blockquote>
*
* will transliterate it and return the result. Other methods allow the client to specify a
* substring to be transliterated and to use {@link Replaceable} objects instead of strings, in
* order to preserve out-of-band information (such as text styles).
*
* <p><b>Keyboard transliteration</b>
*
* <p>Somewhat more involved is <em>keyboard</em>, or incremental transliteration. This is the
* transliteration of text that is arriving from some source (typically the user's keyboard) one
* character at a time, or in some other piecemeal fashion.
*
* <p>In keyboard transliteration, a <code>Replaceable</code> buffer stores the text. As text is
* inserted, as much as possible is transliterated on the fly. This means a GUI that displays the
* contents of the buffer may show text being modified as each new character arrives.
*
* <p>Consider the simple rule-based Transliterator:
*
* <blockquote>
*
* <code>
* th>{theta}<br>
* t>{tau}
* </code>
*
* </blockquote>
*
* When the user types 't', nothing will happen, since the transliterator is waiting to see if the
* next character is 'h'. To remedy this, we introduce the notion of a cursor, marked by a '|' in
* the output string:
*
* <blockquote>
*
* <code>
* t>|{tau}<br>
* {tau}h>{theta}
* </code>
*
* </blockquote>
*
* Now when the user types 't', tau appears, and if the next character is 'h', the tau changes to a
* theta. This is accomplished by maintaining a cursor position (independent of the insertion point,
* and invisible in the GUI) across calls to <code>transliterate()</code>. Typically, the cursor
* will be coincident with the insertion point, but in a case like the one above, it will precede
* the insertion point.
*
* <p>Keyboard transliteration methods maintain a set of three indices that are updated with each
* call to <code>transliterate()</code>, including the cursor, start, and limit. These indices are
* changed by the method, and they are passed in and out via a Position object. The <code>start
* </code> index marks the beginning of the substring that the transliterator will look at. It is
* advanced as text becomes committed (but it is not the committed index; that's the <code>cursor
* </code>). The <code>cursor</code> index, described above, marks the point at which the
* transliterator last stopped, either because it reached the end, or because it required more
* characters to disambiguate between possible inputs. The <code>cursor</code> can also be
* explicitly set by rules. Any characters before the <code>cursor</code> index are frozen; future
* keyboard transliteration calls within this input sequence will not change them. New text is
* inserted at the <code>limit</code> index, which marks the end of the substring that the
* transliterator looks at.
*
* <p>Because keyboard transliteration assumes that more characters are to arrive, it is
* conservative in its operation. It only transliterates when it can do so unambiguously. Otherwise
* it waits for more characters to arrive. When the client code knows that no more characters are
* forthcoming, perhaps because the user has performed some input termination operation, then it
* should call <code>finishTransliteration()</code> to complete any pending transliterations.
*
* <p><b>Inverses</b>
*
* <p>Pairs of transliterators may be inverses of one another. For example, if transliterator
* <b>A</b> transliterates characters by incrementing their Unicode value (so "abc" -> "def"),
* and transliterator <b>B</b> decrements character values, then <b>A</b> is an inverse of <b>B</b>
* and vice versa. If we compose <b>A</b> with <b>B</b> in a compound transliterator, the result is
* the identity transliterator, that is, a transliterator that does not change its input text.
*
* <p>The <code>Transliterator</code> method <code>getInverse()</code> returns a transliterator's
* inverse, if one exists, or <code>null</code> otherwise. However, the result of <code>getInverse()
* </code> usually will <em>not</em> be a true mathematical inverse. This is because true inverse
* transliterators are difficult to formulate. For example, consider two transliterators: <b>AB</b>,
* which transliterates the character 'A' to 'B', and <b>BA</b>, which transliterates 'B' to 'A'. It
* might seem that these are exact inverses, since
*
* <blockquote>
*
* "A" x <b>AB</b> -> "B"<br>
* "B" x <b>BA</b> -> "A"
*
* </blockquote>
*
* where 'x' represents transliteration. However,
*
* <blockquote>
*
* "ABCD" x <b>AB</b> -> "BBCD"<br>
* "BBCD" x <b>BA</b> -> "AACD"
*
* </blockquote>
*
* so <b>AB</b> composed with <b>BA</b> is not the identity. Nonetheless, <b>BA</b> may be usefully
* considered to be <b>AB</b>'s inverse, and it is on this basis that <b>AB</b><code>.getInverse()
* </code> could legitimately return <b>BA</b>.
*
* <p><b>Filtering</b>
*
* <p>Each transliterator has a filter, which restricts changes to those characters selected by the
* filter. The filter affects just the characters that are changed -- the characters outside of the
* filter are still part of the context for the filter. For example, in the following even though
* 'x' is filtered out, and doesn't convert to y, it does affect the conversion of 'a'.
*
* <pre>
* String rules = "x > y; x{a} > b; ";
* Transliterator tempTrans = Transliterator.createFromRules("temp", rules, Transliterator.FORWARD);
* tempTrans.setFilter(new UnicodeSet("[a]"));
* String tempResult = tempTrans.transform("xa");
* // results in "xb"
* </pre>
*
* <p><b>IDs and display names</b>
*
* <p>A transliterator is designated by a short identifier string or <em>ID</em>. IDs follow the
* format <em>source-destination</em>, where <em>source</em> describes the entity being replaced,
* and <em>destination</em> describes the entity replacing <em>source</em>. The entities may be the
* names of scripts, particular sequences of characters, or whatever else it is that the
* transliterator converts to or from. For example, a transliterator from Russian to Latin might be
* named "Russian-Latin". A transliterator from keyboard escape sequences to Latin-1 characters
* might be named "KeyboardEscape-Latin1". By convention, system entity names are in English, with
* the initial letters of words capitalized; user entity names may follow any format so long as they
* do not contain dashes.
*
* <p>In addition to programmatic IDs, transliterator objects have display names for presentation in
* user interfaces, returned by {@link #getDisplayName}.
*
* <p><b>Factory methods and registration</b>
*
* <p>In general, client code should use the factory method <code>getInstance()</code> to obtain an
* instance of a transliterator given its ID. Valid IDs may be enumerated using <code>
* getAvailableIDs()</code>. Since transliterators are stateless, multiple calls to <code>
* getInstance()</code> with the same ID will return the same object.
*
* <p>In addition to the system transliterators registered at startup, user transliterators may be
* registered by calling <code>registerInstance()</code> at run time. To register a transliterator
* subclass without instantiating it (until it is needed), users may call <code>registerClass()
* </code>.
*
* <p><b>Composed transliterators</b>
*
* <p>In addition to built-in system transliterators like "Latin-Greek", there are also built-in
* <em>composed</em> transliterators. These are implemented by composing two or more component
* transliterators. For example, if we have scripts "A", "B", "C", and "D", and we want to
* transliterate between all pairs of them, then we need to write 12 transliterators: "A-B", "A-C",
* "A-D", "B-A",..., "D-A", "D-B", "D-C". If it is possible to convert all scripts to an
* intermediate script "M", then instead of writing 12 rule sets, we only need to write 8: "A~M",
* "B~M", "C~M", "D~M", "M~A", "M~B", "M~C", "M~D". (This might not seem like a big win, but it's
* really 2<em>n</em> vs. <em>n</em> <sup>2</sup> - <em>n</em>, so as <em>n</em> gets larger the
* gain becomes significant. With 9 scripts, it's 18 vs. 72 rule sets, a big difference.) Note the
* use of "~" rather than "-" for the script separator here; this indicates that the given
* transliterator is intended to be composed with others, rather than be used as is.
*
* <p>Composed transliterators can be instantiated as usual. For example, the system transliterator
* "Devanagari-Gujarati" is a composed transliterator built internally as
* "Devanagari~InterIndic;InterIndic~Gujarati". When this transliterator is instantiated, it appears
* externally to be a standard transliterator (e.g., getID() returns "Devanagari-Gujarati").
*
* <p><b>Subclassing</b>
*
* <p>Subclasses must implement the abstract method <code>handleTransliterate()</code>.
*
* <p>Subclasses should override the <code>transliterate()</code> method taking a <code>Replaceable
* </code> and the <code>transliterate()</code> method taking a <code>String</code> and <code>
* StringBuffer</code> if the performance of these methods can be improved over the performance
* obtained by the default implementations in this class.
*
* <p><b>Rule syntax</b>
*
* <p>A set of rules determines how to perform translations. Rules within a rule set are separated
* by semicolons (';'). To include a literal semicolon, prefix it with a backslash ('\'). Unicode
* Pattern_White_Space is ignored. If the first non-blank character on a line is '#', the entire
* line is ignored as a comment.
*
* <p>Each set of rules consists of two groups, one forward, and one reverse. This is a convention
* that is not enforced; rules for one direction may be omitted, with the result that translations
* in that direction will not modify the source text. In addition, bidirectional forward-reverse
* rules may be specified for symmetrical transformations.
*
* <p>Note: Another description of the Transliterator rule syntax is available in <a
* href="https://www.unicode.org/reports/tr35/tr35-general.html#Transform_Rules_Syntax">section
* Transform Rules Syntax of UTS #35: Unicode LDML</a>. The rules are shown there using arrow
* symbols ← and → and ↔. ICU supports both those and the equivalent ASCII symbols < and > and
* <>.
*
* <p>Rule statements take one of the following forms:
*
* <dl>
* <dt><code>$alefmadda=\\u0622;</code>
* <dd><strong>Variable definition.</strong> The name on the left is assigned the text on the
* right. In this example, after this statement, instances of the left hand name, "<code>
* $alefmadda</code>", will be replaced by the Unicode character U+0622. Variable names
* must begin with a letter and consist only of letters, digits, and underscores. Case is
* significant. Duplicate names cause an exception to be thrown, that is, variables cannot be
* redefined. The right hand side may contain well-formed text of any length, including no
* text at all ("<code>$empty=;</code>"). The right hand side may contain embedded
* <code>UnicodeSet</code> patterns, for example, "<code>$softvowel=[eiyEIY]</code>
* ".
* <dt><code>ai>$alefmadda;</code>
* <dd><strong>Forward translation rule.</strong> This rule states that the string on the left
* will be changed to the string on the right when performing forward transliteration.
* <dt><code>ai<$alefmadda;</code>
* <dd><strong>Reverse translation rule.</strong> This rule states that the string on the right
* will be changed to the string on the left when performing reverse transliteration.
* </dl>
*
* <dl>
* <dt><code>ai<>$alefmadda;</code>
* <dd><strong>Bidirectional translation rule.</strong> This rule states that the string on the
* right will be changed to the string on the left when performing forward transliteration,
* and vice versa when performing reverse transliteration.
* </dl>
*
* <p>Translation rules consist of a <em>match pattern</em> and an <em>output string</em>. The match
* pattern consists of literal characters, optionally preceded by context, and optionally followed
* by context. Context characters, like literal pattern characters, must be matched in the text
* being transliterated. However, unlike literal pattern characters, they are not replaced by the
* output text. For example, the pattern "<code>abc{def}</code>" indicates the characters
* "<code>def</code>" must be preceded by "<code>abc</code>" for a successful
* match. If there is a successful match, "<code>def</code>" will be replaced, but not
* "<code>abc</code>". The final '<code>}</code>' is optional, so "<code>abc{def
* </code>" is equivalent to "<code>abc{def}</code>". Another example is "<code>
* {123}456</code>" (or "<code>123}456</code>") in which the literal pattern "
* <code>123</code>" must be followed by "<code>456</code>".
*
* <p>The output string of a forward or reverse rule consists of characters to replace the literal
* pattern characters. If the output string contains the character '<code>|</code>', this is taken
* to indicate the location of the <em>cursor</em> after replacement. The cursor is the point in the
* text at which the next replacement, if any, will be applied. The cursor is usually placed within
* the replacement text; however, it can actually be placed into the precending or following context
* by using the special character '@'. Examples:
*
* <pre>
* a {foo} z > | @ bar; # foo -> bar, move cursor before a
* {foo} xyz > bar @@|; # foo -> bar, cursor between y and z
* </pre>
*
* <p><b>UnicodeSet</b>
*
* <p><code>UnicodeSet</code> patterns may appear anywhere that makes sense. They may appear in
* variable definitions. Contrariwise, <code>UnicodeSet</code> patterns may themselves contain
* variable references, such as "<code>$a=[a-z];$not_a=[^$a]</code>", or "<code>
* $range=a-z;$ll=[$range]</code>".
*
* <p><code>UnicodeSet</code> patterns may also be embedded directly into rule strings. Thus, the
* following two rules are equivalent:
*
* <pre>
* $vowel=[aeiou]; $vowel>'*'; # One way to do this
* [aeiou]>'*'; # Another way
* </pre>
*
* <p>See {@link UnicodeSet} for more documentation and examples.
*
* <p><b>Segments</b>
*
* <p>Segments of the input string can be matched and copied to the output string. This makes
* certain sets of rules simpler and more general, and makes reordering possible. For example:
*
* <pre>
* ([a-z]) > $1 $1; # double lowercase letters
* ([:Lu:]) ([:Ll:]) > $2 $1; # reverse order of Lu-Ll pairs
* </pre>
*
* <p>The segment of the input string to be copied is delimited by "<code>(</code>" and
* "<code>)</code>". Up to nine segments may be defined. Segments may not overlap. In the
* output string, "<code>$1</code>" through "<code>$9</code>" represent the
* input string segments, in left-to-right order of definition.
*
* <p><b>Anchors</b>
*
* <p>Patterns can be anchored to the beginning or the end of the text. This is done with the
* special characters '<code>^</code>' and '<code>$</code>'. For example:
*
* <pre>
* ^ a > 'BEG_A'; # match 'a' at start of text
* a > 'A'; # match other instances of 'a'
* z $ > 'END_Z'; # match 'z' at end of text
* z > 'Z'; # match other instances of 'z'
* </pre>
*
* <p>It is also possible to match the beginning or the end of the text using a <code>UnicodeSet
* </code>. This is done by including a virtual anchor character '<code>$</code>' at the end of the
* set pattern. Although this is usually the match character for the end anchor, the set will match
* either the beginning or the end of the text, depending on its placement. For example:
*
* <pre>
* $x = [a-z$]; # match 'a' through 'z' OR anchor
* $x 1 > 2; # match '1' after a-z or at the start
* 3 $x > 4; # match '3' before a-z or at the end
* </pre>
*
* <p><b>Example</b>
*
* <p>The following example rules illustrate many of the features of the rule language.
*
* <table style="border:none;padding:4px;">
* <tr>
* <td style="vertical-align: top;">Rule 1.</td>
* <td style="vertical-align: top; write-space: nowrap;"><code>abc{def}>x|y</code></td>
* </tr>
* <tr>
* <td style="vertical-align: top;">Rule 2.</td>
* <td style="vertical-align: top; write-space: nowrap;"><code>xyz>r</code></td>
* </tr>
* <tr>
* <td style="vertical-align: top;">Rule 3.</td>
* <td style="vertical-align: top; write-space: nowrap;"><code>yz>q</code></td>
* </tr>
* </table>
*
* <p>Applying these rules to the string "<code>adefabcdefz</code>" yields the following
* results:
*
* <table style="border:none;padding:4px;">
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>|adefabcdefz</code></td>
* <td style="vertical-align: top;">Initial state, no rules match. Advance
* cursor.</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>a|defabcdefz</code></td>
* <td style="vertical-align: top;">Still no match. Rule 1 does not match
* because the preceding context is not present.</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>ad|efabcdefz</code></td>
* <td style="vertical-align: top;">Still no match. Keep advancing until
* there is a match...</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>ade|fabcdefz</code></td>
* <td style="vertical-align: top;">...</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>adef|abcdefz</code></td>
* <td style="vertical-align: top;">...</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>adefa|bcdefz</code></td>
* <td style="vertical-align: top;">...</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>adefab|cdefz</code></td>
* <td style="vertical-align: top;">...</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>adefabc|defz</code></td>
* <td style="vertical-align: top;">Rule 1 matches; replace "<code>def</code>"
* with "<code>xy</code>" and back up the cursor
* to before the '<code>y</code>'.</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>adefabcx|yz</code></td>
* <td style="vertical-align: top;">Although "<code>xyz</code>" is
* present, rule 2 does not match because the cursor is
* before the '<code>y</code>', not before the '<code>x</code>'.
* Rule 3 does match. Replace "<code>yz</code>"
* with "<code>q</code>".</td>
* </tr>
* <tr>
* <td style="vertical-align: top; write-space: nowrap;"><code>adefabcxq|</code></td>
* <td style="vertical-align: top;">The cursor is at the end;
* transliteration is complete.</td>
* </tr>
* </table>
*
* <p>The order of rules is significant. If multiple rules may match at some point, the first
* matching rule is applied.
*
* <p>Forward and reverse rules may have an empty output string. Otherwise, an empty left or right
* hand side of any statement is a syntax error.
*
* <p>Single quotes are used to quote any character other than a digit or letter. To specify a
* single quote itself, inside or outside of quotes, use two single quotes in a row. For example,
* the rule "<code>'>'>o''clock</code>" changes the string "<code>></code>
* " to the string "<code>o'clock</code>".
*
* <p><b>Notes</b>
*
* <p>While a Transliterator is being built from rules, it checks that the rules are added in proper
* order. For example, if the rule "a>x" is followed by the rule "ab>y",
* then the second rule will throw an exception. The reason is that the second rule can never be
* triggered, since the first rule always matches anything it matches. In other words, the first
* rule <em>masks</em> the second rule.
*
* @author Alan Liu
* @stable ICU 2.0
*/
public abstract class Transliterator implements StringTransform {
/**
* Direction constant indicating the forward direction in a transliterator, e.g., the forward
* rules of a rule-based Transliterator. An "A-B" transliterator transliterates A to B when
* operating in the forward direction, and B to A when operating in the reverse direction.
*
* @stable ICU 2.0
*/
public static final int FORWARD = 0;
/**
* Direction constant indicating the reverse direction in a transliterator, e.g., the reverse
* rules of a rule-based Transliterator. An "A-B" transliterator transliterates A to B when
* operating in the forward direction, and B to A when operating in the reverse direction.
*
* @stable ICU 2.0
*/
public static final int REVERSE = 1;
/**
* Position structure for incremental transliteration. This data structure defines two
* substrings of the text being transliterated. The first region, [contextStart, contextLimit),
* defines what characters the transliterator will read as context. The second region, [start,
* limit), defines what characters will actually be transliterated. The second region should be
* a subset of the first.
*
* <p>After a transliteration operation, some of the indices in this structure will be modified.
* See the field descriptions for details.
*
* <p>contextStart <= start <= limit <= contextLimit
*
* <p>Note: All index values in this structure must be at code point boundaries. That is, none
* of them may occur between two code units of a surrogate pair. If any index does split a
* surrogate pair, results are unspecified.
*
* @stable ICU 2.0
*/
public static class Position {
/**
* Beginning index, inclusive, of the context to be considered for a transliteration
* operation. The transliterator will ignore anything before this index. INPUT/OUTPUT
* parameter: This parameter is updated by a transliteration operation to reflect the
* maximum amount of antecontext needed by a transliterator.
*
* @stable ICU 2.0
*/
public int contextStart;
/**
* Ending index, exclusive, of the context to be considered for a transliteration operation.
* The transliterator will ignore anything at or after this index. INPUT/OUTPUT parameter:
* This parameter is updated to reflect changes in the length of the text, but points to the
* same logical position in the text.
*
* @stable ICU 2.0
*/
public int contextLimit;
/**
* Beginning index, inclusive, of the text to be transliteratd. INPUT/OUTPUT parameter: This
* parameter is advanced past characters that have already been transliterated by a
* transliteration operation.
*
* @stable ICU 2.0
*/
public int start;
/**
* Ending index, exclusive, of the text to be transliteratd. INPUT/OUTPUT parameter: This
* parameter is updated to reflect changes in the length of the text, but points to the same
* logical position in the text.
*
* @stable ICU 2.0
*/
public int limit;
/**
* Constructs a Position object with start, limit, contextStart, and contextLimit all equal
* to zero.
*
* @stable ICU 2.0
*/
public Position() {
this(0, 0, 0, 0);
}
/**
* Constructs a Position object with the given start, contextStart, and contextLimit. The
* limit is set to the contextLimit.
*
* @stable ICU 2.0
*/
public Position(int contextStart, int contextLimit, int start) {
this(contextStart, contextLimit, start, contextLimit);
}
/**
* Constructs a Position object with the given start, limit, contextStart, and contextLimit.
*
* @stable ICU 2.0
*/
public Position(int contextStart, int contextLimit, int start, int limit) {
this.contextStart = contextStart;
this.contextLimit = contextLimit;
this.start = start;
this.limit = limit;
}
/**
* Constructs a Position object that is a copy of another.
*
* @stable ICU 2.6
*/
public Position(Position pos) {
set(pos);
}
/**
* Copies the indices of this position from another.
*
* @stable ICU 2.6
*/
public void set(Position pos) {
contextStart = pos.contextStart;
contextLimit = pos.contextLimit;
start = pos.start;
limit = pos.limit;
}
/**
* Returns true if this Position is equal to the given object.
*
* @stable ICU 2.0
*/
@Override
public boolean equals(Object obj) {
if (obj instanceof Position) {
Position pos = (Position) obj;
return contextStart == pos.contextStart
&& contextLimit == pos.contextLimit
&& start == pos.start
&& limit == pos.limit;
}
return false;
}
/**
* {@inheritDoc}
*
* @stable ICU 2.0
*/
@Override
public int hashCode() {
return Objects.hash(contextStart, contextLimit, start, limit);
}
/**
* Returns a string representation of this Position.
*
* @return a string representation of the object.
* @stable ICU 2.0
*/
@Override
public String toString() {
return "[cs="
+ contextStart
+ ", s="
+ start
+ ", l="
+ limit
+ ", cl="
+ contextLimit
+ "]";
}
/**
* Check all bounds. If they are invalid, throw an exception.
*
* @param length the length of the string this object applies to
* @exception IllegalArgumentException if any indices are out of bounds
* @stable ICU 2.0
*/
public final void validate(int length) {
if (contextStart < 0
|| start < contextStart
|| limit < start
|| contextLimit < limit
|| length < contextLimit) {
throw new IllegalArgumentException(
"Invalid Position {cs="
+ contextStart
+ ", s="
+ start
+ ", l="
+ limit
+ ", cl="
+ contextLimit
+ "}, len="
+ length);
}
}
}
/** Programmatic name, e.g., "Latin-Arabic". */
private String ID;
/**
* This transliterator's filter. Any character for which {@code filter.contains()} returns
* {@code false} will not be altered by this transliterator. If {@code filter} is {@code null}
* then no filtering is applied.
*/
private UnicodeSet filter;
private int maximumContextLength = 0;
/** System transliterator registry. */
private static TransliteratorRegistry registry;
private static Map<CaseInsensitiveString, String> displayNameCache;
/**
* Prefix for resource bundle key for the display name for a transliterator. The ID is appended
* to this to form the key. The resource bundle value should be a String.
*/
private static final String RB_DISPLAY_NAME_PREFIX = "%Translit%%";
/**
* Prefix for resource bundle key for the display name for a transliterator SCRIPT. The ID is
* appended to this to form the key. The resource bundle value should be a String.
*/
private static final String RB_SCRIPT_DISPLAY_NAME_PREFIX = "%Translit%";
/**
* Resource bundle key for display name pattern. The resource bundle value should be a String
* forming a MessageFormat pattern, e.g.: "{0,choice,0#|1#{1} Transliterator|2#{1} to {2}
* Transliterator}".
*/
private static final String RB_DISPLAY_NAME_PATTERN = "TransliteratorNamePattern";
/** Delimiter between elements in a compound ID. */
static final char ID_DELIM = ';';
/** Delimiter before target in an ID. */
static final char ID_SEP = '-';
/** Delimiter before variant in an ID. */
static final char VARIANT_SEP = '/';
/**
* To enable debugging output in the Transliterator component, set DEBUG to true.
*
* <p>N.B. Make sure to recompile all of the com.ibm.icu.text package after changing this.
* Easiest way to do this is 'ant clean core' ('ant' will NOT pick up the dependency
* automatically).
*
* <p><<This generates a lot of output.>>
*/
static final boolean DEBUG = false;
/**
* Default constructor.
*
* @param ID the string identifier for this transliterator
* @param filter the filter. Any character for which {@code filter.contains()} returns {@code
* false} will not be altered by this transliterator. If {@code filter} is {@code null} then
* no filtering is applied.
* @stable ICU 2.0
*/
protected Transliterator(String ID, UnicodeFilter filter) {
if (ID == null) {
throw new NullPointerException();
}
this.ID = ID;
setFilter(filter);
}
/**
* Transliterates a segment of a string, with optional filtering.
*
* @param text the string to be transliterated
* @param start the beginning index, inclusive; <code>0 <= start
* <= limit</code>.
* @param limit the ending index, exclusive; <code>start <= limit
* <= text.length()</code>.
* @return The new limit index. The text previously occupying <code>[start,
* limit)</code> has been transliterated, possibly to a string of a different length, at <code>
* [start, </code><em>new-limit</em><code>)</code>, where <em>new-limit</em> is the return
* value. If the input offsets are out of bounds, the returned value is -1 and the input
* string remains unchanged.
* @stable ICU 2.0
*/
public final int transliterate(Replaceable text, int start, int limit) {
if (start < 0 || limit < start || text.length() < limit) {
return -1;
}
Position pos = new Position(start, limit, start);
filteredTransliterate(text, pos, false, true);
return pos.limit;
}
/**
* Transliterates an entire string in place. Convenience method.
*
* @param text the string to be transliterated
* @stable ICU 2.0
*/
public final void transliterate(Replaceable text) {
transliterate(text, 0, text.length());
}
/**
* Transliterate an entire string and returns the result. Convenience method.
*
* @param text the string to be transliterated
* @return The transliterated text
* @stable ICU 2.0
*/
public final String transliterate(String text) {
ReplaceableString result = new ReplaceableString(text);
transliterate(result);
return result.toString();
}
/**
* Transliterates the portion of the text buffer that can be transliterated unambiguosly after
* new text has been inserted, typically as a result of a keyboard event. The new text in <code>
* insertion</code> will be inserted into <code>text</code> at <code>index.contextLimit</code>,
* advancing <code>index.contextLimit</code> by <code>insertion.length()</code>. Then the
* transliterator will try to transliterate characters of <code>text</code> between <code>
* index.start</code> and <code>index.contextLimit</code>. Characters before <code>index.start
* </code> will not be changed.
*
* <p>Upon return, values in <code>index</code> will be updated. <code>index.contextStart</code>
* will be advanced to the first character that future calls to this method will read. <code>
* index.start</code> and <code>index.contextLimit</code> will be adjusted to delimit the range
* of text that future calls to this method may change.
*
* <p>Typical usage of this method begins with an initial call with <code>index.contextStart
* </code> and <code>index.contextLimit</code> set to indicate the portion of <code>text</code>
* to be transliterated, and <code>index.start == index.contextStart</code>. Thereafter, <code>
* index</code> can be used without modification in future calls, provided that all changes to
* <code>text</code> are made via this method.
*
* <p>This method assumes that future calls may be made that will insert new text into the
* buffer. As a result, it only performs unambiguous transliterations. After the last call to
* this method, there may be untransliterated text that is waiting for more input to resolve an
* ambiguity. In order to perform these pending transliterations, clients should call {@link
* #finishTransliteration} after the last call to this method has been made.
*
* @param text the buffer holding transliterated and untransliterated text
* @param index the start and limit of the text, the position of the cursor, and the start and
* limit of transliteration.
* @param insertion text to be inserted and possibly transliterated into the translation buffer
* at <code>index.contextLimit</code>. If <code>null</code> then no text is inserted.
* @see #handleTransliterate
* @exception IllegalArgumentException if <code>index</code> is invalid
* @stable ICU 2.0
*/
public final void transliterate(Replaceable text, Position index, String insertion) {
index.validate(text.length());
// int originalStart = index.contextStart;
if (insertion != null) {
text.replace(index.limit, index.limit, insertion);
index.limit += insertion.length();
index.contextLimit += insertion.length();
}
if (index.limit > 0 && UTF16.isLeadSurrogate(text.charAt(index.limit - 1))) {
// Oops, there is a dangling lead surrogate in the buffer.
// This will break most transliterators, since they will
// assume it is part of a pair. Don't transliterate until
// more text comes in.
return;
}
filteredTransliterate(text, index, true, true);
// TODO
// This doesn't work once we add quantifier support. Need to rewrite
// this code to support quantifiers and 'use maximum backup <n>;'.
//
// index.contextStart = Math.max(index.start - getMaximumContextLength(),
// originalStart);
}
/**
* Transliterates the portion of the text buffer that can be transliterated unambiguosly after a
* new character has been inserted, typically as a result of a keyboard event. This is a
* convenience method; see {@link #transliterate(Replaceable, Transliterator.Position, String)}
* for details.
*
* @param text the buffer holding transliterated and untransliterated text
* @param index the start and limit of the text, the position of the cursor, and the start and
* limit of transliteration.
* @param insertion text to be inserted and possibly transliterated into the translation buffer
* at <code>index.contextLimit</code>.
* @see #transliterate(Replaceable, Transliterator.Position, String)
* @stable ICU 2.0
*/
public final void transliterate(Replaceable text, Position index, int insertion) {
transliterate(text, index, UTF16.valueOf(insertion));
}
/**
* Transliterates the portion of the text buffer that can be transliterated unambiguosly. This
* is a convenience method; see {@link #transliterate(Replaceable, Transliterator.Position,
* String)} for details.
*
* @param text the buffer holding transliterated and untransliterated text
* @param index the start and limit of the text, the position of the cursor, and the start and
* limit of transliteration.
* @see #transliterate(Replaceable, Transliterator.Position, String)
* @stable ICU 2.0
*/
public final void transliterate(Replaceable text, Position index) {
transliterate(text, index, null);
}
/**
* Finishes any pending transliterations that were waiting for more characters. Clients should
* call this method as the last call after a sequence of one or more calls to <code>
* transliterate()</code>.
*
* @param text the buffer holding transliterated and untransliterated text.
* @param index the array of indices previously passed to {@link #transliterate}
* @stable ICU 2.0
*/
public final void finishTransliteration(Replaceable text, Position index) {
index.validate(text.length());
filteredTransliterate(text, index, false, true);
}
/**
* Abstract method that concrete subclasses define to implement their transliteration algorithm.
* This method handles both incremental and non-incremental transliteration. Let <code>
* originalStart</code> refer to the value of <code>pos.start</code> upon entry.
*
* <ul>
* <li>If <code>incremental</code> is false, then this method should transliterate all
* characters between <code>pos.start</code> and <code>pos.limit</code>. Upon return
* <code>pos.start</code> must == <code> pos.limit</code>.
* <li>If <code>incremental</code> is true, then this method should transliterate all
* characters between <code>pos.start</code> and <code>pos.limit</code> that can be
* unambiguously transliterated, regardless of future insertions of text at <code>
* pos.limit</code>. Upon return, <code>pos.start</code> should be in the range [<code>
* originalStart</code>, <code>pos.limit</code>). <code>pos.start</code> should be
* positioned such that characters [<code>originalStart</code>, <code>
* pos.start</code>) will not be changed in the future by this transliterator and characters [
* <code>pos.start</code>, <code>pos.limit</code>) are unchanged.
* </ul>
*
* <p>Implementations of this method should also obey the following invariants:
*
* <ul>
* <li><code>pos.limit</code> and <code>pos.contextLimit</code> should be updated to reflect
* changes in length of the text between <code>pos.start</code> and <code>pos.limit</code>
* . The difference <code> pos.contextLimit - pos.limit</code> should not change.
* <li><code>pos.contextStart</code> should not change.
* <li>Upon return, neither <code>pos.start</code> nor <code>pos.limit</code> should be less
* than <code>originalStart</code>.
* <li>Text before <code>originalStart</code> and text after <code>pos.limit</code> should not
* change.
* <li>Text before <code>pos.contextStart</code> and text after <code> pos.contextLimit</code>
* should be ignored.
* </ul>
*
* <p>Subclasses may safely assume that all characters in [<code>pos.start</code>, <code>
* pos.limit</code>) are filtered. In other words, the filter has already been applied by the
* time this method is called. See <code>filteredTransliterate()</code>.
*
* <p>This method is <b>not</b> for public consumption. Calling this method directly will
* transliterate [<code>pos.start</code>, <code>pos.limit</code>) without applying the filter.
* End user code should call <code>
* transliterate()</code> instead of this method. Subclass code should call <code>
* filteredTransliterate()</code> instead of this method.
*
* <p>
*
* @param text the buffer holding transliterated and untransliterated text
* @param pos the indices indicating the start, limit, context start, and context limit of the
* text.
* @param incremental if true, assume more text may be inserted at <code>pos.limit</code> and
* act accordingly. Otherwise, transliterate all text between <code>pos.start</code> and
* <code>pos.limit</code> and move <code>pos.start</code> up to <code>pos.limit</code>.
* @see #transliterate
* @stable ICU 2.0
*/
protected abstract void handleTransliterate(
Replaceable text, Position pos, boolean incremental);
/**
* Top-level transliteration method, handling filtering, incremental and non-incremental
* transliteration, and rollback. All transliteration public API methods eventually call this
* method with a rollback argument of true. Other entities may call this method but rollback
* should be false.
*
* <p>If this transliterator has a filter, break up the input text into runs of unfiltered
* characters. Pass each run to <subclass>.handleTransliterate().
*
* <p>In incremental mode, if rollback is true, perform a special incremental procedure in which
* several passes are made over the input text, adding one character at a time, and committing
* successful transliterations as they occur. Unsuccessful transliterations are rolled back and
* retried with additional characters to give correct results.
*
* @param text the text to be transliterated
* @param index the position indices
* @param incremental if true, then assume more characters may be inserted at index.limit, and
* postpone processing to accommodate future incoming characters
* @param rollback if true and if incremental is true, then perform special incremental
* processing, as described above, and undo partial transliterations where necessary. If
* incremental is false then this parameter is ignored.
*/
private void filteredTransliterate(
Replaceable text, Position index, boolean incremental, boolean rollback) {
// Short circuit path for transliterators with no filter in
// non-incremental mode.
if (filter == null && !rollback) {
handleTransliterate(text, index, incremental);
return;
}
// ----------------------------------------------------------------------
// This method processes text in two groupings:
//
// RUNS -- A run is a contiguous group of characters which are contained
// in the filter for this transliterator (filter.contains(ch) == true).
// Text outside of runs may appear as context but it is not modified.
// The start and limit Position values are narrowed to each run.
//
// PASSES (incremental only) -- To make incremental mode work correctly,
// each run is broken up into n passes, where n is the length (in code
// points) of the run. Each pass contains the first n characters. If a
// pass is completely transliterated, it is committed, and further passes
// include characters after the committed text. If a pass is blocked,
// and does not transliterate completely, then this method rolls back
// the changes made during the pass, extends the pass by one code point,
// and tries again.
// ----------------------------------------------------------------------
// globalLimit is the limit value for the entire operation. We
// set index.limit to the end of each unfiltered run before
// calling handleTransliterate(), so we need to maintain the real
// value of index.limit here. After each transliteration, we
// update globalLimit for insertions or deletions that have
// happened.
int globalLimit = index.limit;
// If there is a non-null filter, then break the input text up. Say the
// input text has the form:
// xxxabcxxdefxx
// where 'x' represents a filtered character (filter.contains('x') ==
// false). Then we break this up into:
// xxxabc xxdef xx
// Each pass through the loop consumes a run of filtered
// characters (which are ignored) and a subsequent run of
// unfiltered characters (which are transliterated).
StringBuilder log = null;
if (DEBUG) {
log = new StringBuilder();
}
for (; ; ) {
if (filter != null) {
// Narrow the range to be transliterated to the first run
// of unfiltered characters at or after index.start.
// Advance past filtered chars
int c;
while (index.start < globalLimit
&& !filter.contains(c = text.char32At(index.start))) {
index.start += UTF16.getCharCount(c);
}
// Find the end of this run of unfiltered chars
index.limit = index.start;
while (index.limit < globalLimit
&& filter.contains(c = text.char32At(index.limit))) {
index.limit += UTF16.getCharCount(c);
}
}
// Check to see if the unfiltered run is empty. This only
// happens at the end of the string when all the remaining
// characters are filtered.
if (index.start == index.limit) {
break;
}
// Is this run incremental? If there is additional
// filtered text (if limit < globalLimit) then we pass in
// an incremental value of false to force the subclass to
// complete the transliteration for this run.
boolean isIncrementalRun = (index.limit < globalLimit ? false : incremental);
int delta;
// Implement rollback. To understand the need for rollback,
// consider the following transliterator:
//
// "t" is "a > A;"
// "u" is "A > b;"
// "v" is a compound of "t; NFD; u" with a filter [:Ll:]
//
// Now apply "v" to the input text "a". The result is "b". But if
// the transliteration is done incrementally, then the NFD holds
// things up after "t" has already transformed "a" to "A". When
// finishTransliterate() is called, "A" is _not_ processed because
// it gets excluded by the [:Ll:] filter, and the end result is "A"
// -- incorrect. The problem is that the filter is applied to a
// partially-transliterated result, when we only want it to apply to
// input text. Although this example describes a compound
// transliterator containing NFD and a specific filter, it can
// happen with any transliterator which does a partial
// transformation in incremental mode into characters outside its
// filter.
//
// To handle this, when in incremental mode we supply characters to
// handleTransliterate() in several passes. Each pass adds one more
// input character to the input text. That is, for input "ABCD", we
// first try "A", then "AB", then "ABC", and finally "ABCD". If at
// any point we block (upon return, start < limit) then we roll
// back. If at any point we complete the run (upon return start ==
// limit) then we commit that run.
if (rollback && isIncrementalRun) {
if (DEBUG) {
log.setLength(0);
System.out.println(
"filteredTransliterate{"
+ getID()
+ "}i: IN="
+ UtilityExtensions.formatInput(text, index));
}
int runStart = index.start;
int runLimit = index.limit;
int runLength = runLimit - runStart;
// Make a rollback copy at the end of the string
int rollbackOrigin = text.length();
text.copy(runStart, runLimit, rollbackOrigin);
// Variables reflecting the commitment of completely
// transliterated text. passStart is the runStart, advanced
// past committed text. rollbackStart is the rollbackOrigin,
// advanced past rollback text that corresponds to committed
// text.
int passStart = runStart;
int rollbackStart = rollbackOrigin;
// The limit for each pass; we advance by one code point with
// each iteration.
int passLimit = index.start;
// Total length, in 16-bit code units, of uncommitted text.
// This is the length to be rolled back.
int uncommittedLength = 0;
// Total delta (change in length) for all passes
int totalDelta = 0;
// PASS MAIN LOOP -- Start with a single character, and extend
// the text by one character at a time. Roll back partial
// transliterations and commit complete transliterations.
for (; ; ) {
// Length of additional code point, either one or two
int charLength = UTF16.getCharCount(text.char32At(passLimit));
passLimit += charLength;
if (passLimit > runLimit) {
break;
}
uncommittedLength += charLength;
index.limit = passLimit;
if (DEBUG) {
log.setLength(0);
log.append("filteredTransliterate{" + getID() + "}i: ");
UtilityExtensions.formatInput(log, text, index);
}
// Delegate to subclass for actual transliteration. Upon
// return, start will be updated to point after the
// transliterated text, and limit and contextLimit will be
// adjusted for length changes.
handleTransliterate(text, index, true);
if (DEBUG) {
log.append(" => ");
UtilityExtensions.formatInput(log, text, index);
}
delta = index.limit - passLimit; // change in length
// We failed to completely transliterate this pass.
// Roll back the text. Indices remain unchanged; reset
// them where necessary.
if (index.start != index.limit) {
// Find the rollbackStart, adjusted for length changes
// and the deletion of partially transliterated text.
int rs = rollbackStart + delta - (index.limit - passStart);
// Delete the partially transliterated text
text.replace(passStart, index.limit, "");
// Copy the rollback text back
text.copy(rs, rs + uncommittedLength, passStart);
// Restore indices to their original values
index.start = passStart;
index.limit = passLimit;
index.contextLimit -= delta;
if (DEBUG) {
log.append(" (ROLLBACK)");
}
}
// We did completely transliterate this pass. Update the
// commit indices to record how far we got. Adjust indices
// for length change.
else {
// Move the pass indices past the committed text.
passStart = passLimit = index.start;
// Adjust the rollbackStart for length changes and move
// it past the committed text. All characters we've
// processed to this point are committed now, so zero
// out the uncommittedLength.
rollbackStart += delta + uncommittedLength;
uncommittedLength = 0;
// Adjust indices for length changes.
runLimit += delta;
totalDelta += delta;
}
if (DEBUG) {
System.out.println(Utility.escape(log.toString()));
}
}
// Adjust overall limit and rollbackOrigin for insertions and
// deletions. Don't need to worry about contextLimit because
// handleTransliterate() maintains that.
rollbackOrigin += totalDelta;
globalLimit += totalDelta;
// Delete the rollback copy
text.replace(rollbackOrigin, rollbackOrigin + runLength, "");
// Move start past committed text
index.start = passStart;
} else {
// Delegate to subclass for actual transliteration.
if (DEBUG) {
log.setLength(0);
log.append("filteredTransliterate{" + getID() + "}: ");
UtilityExtensions.formatInput(log, text, index);
}
int limit = index.limit;
handleTransliterate(text, index, isIncrementalRun);
delta = index.limit - limit; // change in length
if (DEBUG) {
log.append(" => ");
UtilityExtensions.formatInput(log, text, index);
}
// In a properly written transliterator, start == limit after
// handleTransliterate() returns when incremental is false.
// Catch cases where the subclass doesn't do this, and throw
// an exception. (Just pinning start to limit is a bad idea,
// because what's probably happening is that the subclass
// isn't transliterating all the way to the end, and it should
// in non-incremental mode.)
if (!isIncrementalRun && index.start != index.limit) {
throw new RuntimeException(
"ERROR: Incomplete non-incremental transliteration by " + getID());
}
// Adjust overall limit for insertions/deletions. Don't need
// to worry about contextLimit because handleTransliterate()
// maintains that.
globalLimit += delta;
if (DEBUG) {
System.out.println(Utility.escape(log.toString()));
}
}
if (filter == null || isIncrementalRun) {
break;
}
// If we did completely transliterate this
// run, then repeat with the next unfiltered run.
}
// Start is valid where it is. Limit needs to be put back where
// it was, modulo adjustments for deletions/insertions.
index.limit = globalLimit;
if (DEBUG) {
System.out.println(
"filteredTransliterate{"
+ getID()
+ "}: OUT="
+ UtilityExtensions.formatInput(text, index));
}
}
/**
* Transliterate a substring of text, as specified by index, taking filters into account. This
* method is for subclasses that need to delegate to another transliterator.
*
* @param text the text to be transliterated
* @param index the position indices
* @param incremental if true, then assume more characters may be inserted at index.limit, and
* postpone processing to accommodate future incoming characters
* @stable ICU 2.0
*/
public void filteredTransliterate(Replaceable text, Position index, boolean incremental) {
filteredTransliterate(text, index, incremental, false);
}
/**
* Returns the length of the longest context required by this transliterator. This is
* <em>preceding</em> context. The default value is zero, but subclasses can change this by
* calling <code>setMaximumContextLength()</code>. For example, if a transliterator translates
* "ddd" (where d is any digit) to "555" when preceded by "(ddd)", then the preceding context
* length is 5, the length of "(ddd)".
*
* @return The maximum number of preceding context characters this transliterator needs to
* examine
* @stable ICU 2.0
*/
public final int getMaximumContextLength() {
return maximumContextLength;
}
/**
* Method for subclasses to use to set the maximum context length.
*
* @see #getMaximumContextLength
* @stable ICU 2.0
*/
protected void setMaximumContextLength(int a) {
if (a < 0) {
throw new IllegalArgumentException("Invalid context length " + a);
}
maximumContextLength = a;
}
/**
* Returns a programmatic identifier for this transliterator. If this identifier is passed to
* <code>getInstance()</code>, it will return this object, if it has been registered.
*
* @see #registerClass
* @see #getAvailableIDs
* @stable ICU 2.0
*/
public final String getID() {
return ID;
}
/**
* Set the programmatic identifier for this transliterator. Only for use by subclasses.
*
* @stable ICU 2.0
*/
protected final void setID(String id) {
ID = id;
}
/**
* Returns a name for this transliterator that is appropriate for display to the user in the
* default <code>DISPLAY</code> locale. See {@link #getDisplayName(String,Locale)} for details.
*
* @see com.ibm.icu.util.ULocale.Category#DISPLAY
* @stable ICU 2.0
*/
public static final String getDisplayName(String ID) {
return getDisplayName(ID, ULocale.getDefault(Category.DISPLAY));
}
/**
* Returns a name for this transliterator that is appropriate for display to the user in the
* given locale. This name is taken from the locale resource data in the standard manner of the
* <code>java.text</code> package.
*
* <p>If no localized names exist in the system resource bundles, a name is synthesized using a
* localized <code>MessageFormat</code> pattern from the resource data. The arguments to this
* pattern are an integer followed by one or two strings. The integer is the number of strings,
* either 1 or 2. The strings are formed by splitting the ID for this transliterator at the
* first '-'. If there is no '-', then the entire ID forms the only string.
*
* @param inLocale the Locale in which the display name should be localized.
* @see java.text.MessageFormat
* @stable ICU 2.0
*/
public static String getDisplayName(String id, Locale inLocale) {
return getDisplayName(id, ULocale.forLocale(inLocale));
}
/**
* Returns a name for this transliterator that is appropriate for display to the user in the
* given locale. This name is taken from the locale resource data in the standard manner of the
* <code>java.text</code> package.
*
* <p>If no localized names exist in the system resource bundles, a name is synthesized using a
* localized <code>MessageFormat</code> pattern from the resource data. The arguments to this
* pattern are an integer followed by one or two strings. The integer is the number of strings,
* either 1 or 2. The strings are formed by splitting the ID for this transliterator at the
* first '-'. If there is no '-', then the entire ID forms the only string.
*
* @param inLocale the ULocale in which the display name should be localized.
* @see java.text.MessageFormat
* @stable ICU 3.2
*/
public static String getDisplayName(String id, ULocale inLocale) {
// Resource bundle containing display name keys and the
// RB_RULE_BASED_IDS array.
//
// If we ever integrate this with the Sun JDK, the resource bundle
// root will change to sun.text.resources.LocaleElements
ICUResourceBundle bundle =
(ICUResourceBundle)
UResourceBundle.getBundleInstance(ICUData.ICU_TRANSLIT_BASE_NAME, inLocale);
// Normalize the ID
String stv[] = TransliteratorIDParser.IDtoSTV(id);
if (stv == null) {
// No target; malformed id
return "";
}
String ID = stv[0] + '-' + stv[1];
if (stv[2] != null && stv[2].length() > 0) {
ID = ID + '/' + stv[2];
}
// Use the registered display name, if any
String n = displayNameCache.get(new CaseInsensitiveString(ID));
if (n != null) {
return n;
}
// Use display name for the entire transliterator, if it
// exists.
try {
return bundle.getString(RB_DISPLAY_NAME_PREFIX + ID);
} catch (MissingResourceException e) {
}
try {
// Construct the formatter first; if getString() fails
// we'll exit the try block
MessageFormat format = new MessageFormat(bundle.getString(RB_DISPLAY_NAME_PATTERN));
// Construct the argument array
Object[] args = new Object[] {2, stv[0], stv[1]};
// Use display names for the scripts, if they exist
for (int j = 1; j <= 2; ++j) {
try {
args[j] = bundle.getString(RB_SCRIPT_DISPLAY_NAME_PREFIX + (String) args[j]);
} catch (MissingResourceException e) {
}
}
// Format it using the pattern in the resource
return (stv[2].length() > 0)
? (format.format(args) + '/' + stv[2])
: format.format(args);
} catch (MissingResourceException e2) {
}
// We should not reach this point unless there is something
// wrong with the build or the RB_DISPLAY_NAME_PATTERN has
// been deleted from the root RB_LOCALE_ELEMENTS resource.
throw new RuntimeException();
}
/**
* Returns the filter used by this transliterator, or {@code null} if this transliterator uses
* no filter.
*
* @stable ICU 2.0
*/
public final UnicodeFilter getFilter() {
return filter;
}
/**
* Changes the filter used by this transliterator. If the filter is set to {@code null} then no
* filtering will occur.
*
* <p>Callers must take care if a transliterator is in use by multiple threads. The filter
* should not be changed by one thread while another thread may be transliterating.
*
* @stable ICU 2.0
*/
public void setFilter(UnicodeFilter filter) {
if (filter == null) {
this.filter = null;
} else {
try {
// fast high-runner case
this.filter = new UnicodeSet((UnicodeSet) filter).freeze();
} catch (Exception e) {
this.filter = new UnicodeSet();
filter.addMatchSetTo(this.filter);
this.filter.freeze();
}
}
}
/**
* Returns a <code>Transliterator</code> object given its ID. The ID must be either a system
* transliterator ID or a ID registered using <code>registerClass()</code>.
*
* @param ID a valid ID, as enumerated by <code>getAvailableIDs()</code>
* @return A <code>Transliterator</code> object with the given ID
* @exception IllegalArgumentException if the given ID is invalid.
* @stable ICU 2.0
*/
public static final Transliterator getInstance(String ID) {
return getInstance(ID, FORWARD);
}
/**
* Returns a <code>Transliterator</code> object given its ID. The ID must be either a system
* transliterator ID or a ID registered using <code>registerClass()</code>.
*
* @param ID a valid ID, as enumerated by <code>getAvailableIDs()</code>
* @param dir either FORWARD or REVERSE. If REVERSE then the inverse of the given ID is
* instantiated.
* @return A <code>Transliterator</code> object with the given ID
* @exception IllegalArgumentException if the given ID is invalid.
* @see #registerClass
* @see #getAvailableIDs
* @see #getID
* @stable ICU 2.0
*/
public static Transliterator getInstance(String ID, int dir) {
StringBuilder canonID = new StringBuilder();
List<SingleID> list = new ArrayList<>();
UnicodeSet[] globalFilter = new UnicodeSet[1];
if (!TransliteratorIDParser.parseCompoundID(ID, dir, canonID, list, globalFilter)) {
throw new IllegalArgumentException("Invalid ID " + ID);
}
List<Transliterator> translits = TransliteratorIDParser.instantiateList(list);
// assert(list.size() > 0);
Transliterator t = null;
if (list.size() > 1 || canonID.indexOf(";") >= 0) {
// [NOTE: If it's a compoundID, we instantiate a CompoundTransliterator even if it only
// has one child transliterator. This is so that toRules() will return the right thing
// (without any inactive ID), but our main ID still comes out correct. That is, if we
// instantiate "(Lower);Latin-Greek;", we want the rules to come out as "::Latin-Greek;"
// even though the ID is "(Lower);Latin-Greek;".
t = new CompoundTransliterator(translits);
} else {
t = translits.get(0);
}
t.setID(canonID.toString());
if (globalFilter[0] != null) {
t.setFilter(globalFilter[0]);
}
return t;
}
/**
* Create a transliterator from a basic ID. This is an ID containing only the forward direction
* source, target, and variant.
*
* @param id a basic ID of the form S-T or S-T/V.
* @param canonID canonical ID to apply to the result, or null to leave the ID unchanged
* @return a newly created Transliterator or null if the ID is invalid.
*/
static Transliterator getBasicInstance(String id, String canonID) {
StringBuilder s = new StringBuilder();
Transliterator t = registry.get(id, s);
if (s.length() != 0) {
// assert(t==0);
// Instantiate an alias
t = getInstance(s.toString(), FORWARD);
}
if (t != null && canonID != null) {
t.setID(canonID);
}
return t;
}
/**
* Returns a <code>Transliterator</code> object constructed from the given rule string. This
* will be a rule-based Transliterator, if the rule string contains only rules, or a compound
* Transliterator, if it contains ID blocks, or a null Transliterator, if it contains ID blocks
* which parse as empty for the given direction.
*
* @param ID the id for the transliterator.
* @param rules rules, separated by ';'
* @param dir either FORWARD or REVERSE.
* @return a newly created Transliterator
* @throws IllegalArgumentException if there is a problem with the ID or the rules
* @stable ICU 2.0
*/
public static final Transliterator createFromRules(String ID, String rules, int dir) {
Transliterator t = null;
TransliteratorParser parser = new TransliteratorParser();
parser.parse(rules, dir);
// NOTE: The logic here matches that in TransliteratorRegistry.
if (parser.idBlockVector.size() == 0 && parser.dataVector.size() == 0) {
t = new NullTransliterator();
} else if (parser.idBlockVector.size() == 0 && parser.dataVector.size() == 1) {
t = new RuleBasedTransliterator(ID, parser.dataVector.get(0), parser.compoundFilter);
} else if (parser.idBlockVector.size() == 1 && parser.dataVector.size() == 0) {
// idBlock, no data -- this is an alias. The ID has
// been munged from reverse into forward mode, if
// necessary, so instantiate the ID in the forward
// direction.
if (parser.compoundFilter != null) {
t =
getInstance(
parser.compoundFilter.toPattern(false)
+ ";"
+ parser.idBlockVector.get(0));
} else {
t = getInstance(parser.idBlockVector.get(0));
}
if (t != null) {
t.setID(ID);
}
} else {
List<Transliterator> transliterators = new ArrayList<>();
int passNumber = 1;
int limit = Math.max(parser.idBlockVector.size(), parser.dataVector.size());
for (int i = 0; i < limit; i++) {
if (i < parser.idBlockVector.size()) {
String idBlock = parser.idBlockVector.get(i);
if (idBlock.length() > 0) {
Transliterator temp = getInstance(idBlock);
if (!(temp instanceof NullTransliterator))
transliterators.add(getInstance(idBlock));
}
}
if (i < parser.dataVector.size()) {
Data data = parser.dataVector.get(i);
transliterators.add(
new RuleBasedTransliterator("%Pass" + passNumber++, data, null));
}
}
t = new CompoundTransliterator(transliterators, passNumber - 1);
t.setID(ID);
if (parser.compoundFilter != null) {
t.setFilter(parser.compoundFilter);
}
}
return t;
}
/**
* Returns a rule string for this transliterator.
*
* @param escapeUnprintable if true, then unprintable characters will be converted to escape
* form backslash-'u' or backslash-'U'.
* @stable ICU 2.0
*/
public String toRules(boolean escapeUnprintable) {
return baseToRules(escapeUnprintable);
}
/**
* Returns a rule string for this transliterator. This is a non-overrideable base class
* implementation that subclasses may call. It simply munges the ID into the correct format,
* that is, "foo" => "::foo".
*
* @param escapeUnprintable if true, then unprintable characters will be converted to escape
* form backslash-'u' or backslash-'U'.
* @stable ICU 2.0
*/
protected final String baseToRules(boolean escapeUnprintable) {
// The base class implementation of toRules munges the ID into
// the correct format. That is: foo => ::foo
// KEEP in sync with rbt_pars
if (escapeUnprintable) {
StringBuilder rulesSource = new StringBuilder();
String id = getID();
for (int i = 0; i < id.length(); ) {
int c = UTF16.charAt(id, i);
if (!Utility.escapeUnprintable(rulesSource, c)) {
rulesSource.appendCodePoint(c);
}
i += UTF16.getCharCount(c);
}
rulesSource.insert(0, "::");
rulesSource.append(ID_DELIM);
return rulesSource.toString();
}
return "::" + getID() + ID_DELIM;
}
/**
* Return the elements that make up this transliterator. For example, if the transliterator
* "NFD;Jamo-Latin;Latin-Greek" were created, the return value of this method would be an array
* of the three transliterator objects that make up that transliterator: [NFD, Jamo-Latin,
* Latin-Greek].
*
* <p>If this transliterator is not composed of other transliterators, then this method will
* return an array of length one containing a reference to this transliterator.
*
* @return an array of one or more transliterators that make up this transliterator
* @stable ICU 3.0
*/
public Transliterator[] getElements() {
Transliterator result[];
if (this instanceof CompoundTransliterator) {
CompoundTransliterator cpd = (CompoundTransliterator) this;
result = new Transliterator[cpd.getCount()];
for (int i = 0; i < result.length; ++i) {
result[i] = cpd.getTransliterator(i);
}
} else {
result = new Transliterator[] {this};
}
return result;
}
/**
* Returns the set of all characters that may be modified in the input text by this
* Transliterator. This incorporates this object's current filter; if the filter is changed, the
* return value of this function will change. The default implementation returns an empty set.
* Some subclasses may override {@link #handleGetSourceSet} to return a more precise result. The
* return result is approximate in any case and is intended for use by tests, tools, or
* utilities.
*
* @see #getTargetSet
* @see #handleGetSourceSet
* @stable ICU 2.2
*/
public final UnicodeSet getSourceSet() {
UnicodeSet result = new UnicodeSet();
addSourceTargetSet(
getFilterAsUnicodeSet(UnicodeSet.ALL_CODE_POINTS), result, new UnicodeSet());
return result;
}
/**
* Framework method that returns the set of all characters that may be modified in the input
* text by this Transliterator, ignoring the effect of this object's filter. The base class
* implementation returns the empty set. Subclasses that wish to implement this should override
* this method.
*
* @return the set of characters that this transliterator may modify. The set may be modified,
* so subclasses should return a newly-created object.
* @see #getSourceSet
* @see #getTargetSet
* @stable ICU 2.2
*/
protected UnicodeSet handleGetSourceSet() {
return new UnicodeSet();
}
/**
* Returns the set of all characters that may be generated as replacement text by this
* transliterator. The default implementation returns the empty set. Some subclasses may
* override this method to return a more precise result. The return result is approximate in any
* case and is intended for use by tests, tools, or utilities requiring such meta-information.
*
* <p>Warning. You might expect an empty filter to always produce an empty target. However,
* consider the following:
*
* <pre>
* [Pp]{}[\u03A3\u03C2\u03C3\u03F7\u03F8\u03FA\u03FB] > \';
* </pre>
*
* With a filter of [], you still get some elements in the target set, because this rule will
* still match. It could be recast to the following if it were important.
*
* <pre>
* [Pp]{([\u03A3\u03C2\u03C3\u03F7\u03F8\u03FA\u03FB])} > \' | $1;
* </pre>
*
* @see #getTargetSet
* @stable ICU 2.2
*/
public UnicodeSet getTargetSet() {
UnicodeSet result = new UnicodeSet();
addSourceTargetSet(
getFilterAsUnicodeSet(UnicodeSet.ALL_CODE_POINTS), new UnicodeSet(), result);
return result;
}
/**
* Returns the set of all characters that may be generated as replacement text by this
* transliterator, filtered by BOTH the input filter, and the current getFilter().
*
* <p>SHOULD BE OVERRIDDEN BY SUBCLASSES. It is probably an error for any transliterator to NOT
* override this, but we can't force them to for backwards compatibility.
*
* <p>Other methods vector through this.
*
* <p>When gathering the information on source and target, the compound transliterator makes
* things complicated. For example, suppose we have:
*
* <pre>
* Global FILTER = [ax]
* a > b;
* :: NULL;
* b > c;
* x > d;
* </pre>
*
* While the filter just allows a and x, b is an intermediate result, which could produce c. So
* the source and target sets cannot be gathered independently. What we have to do is filter the
* sources for the first transliterator according to the global filter, intersect that
* transliterator's filter. Based on that we get the target. The next transliterator gets as a
* global filter (global + last target). And so on.
*
* <p>There is another complication:
*
* <pre>
* Global FILTER = [ax]
* a >|b;
* b >c;
* </pre>
*
* Even though b would be filtered from the input, whenever we have a backup, it could be part
* of the input. So ideally we will change the global filter as we go.
*
* @param targetSet TODO
* @see #getTargetSet
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public void addSourceTargetSet(
UnicodeSet inputFilter, UnicodeSet sourceSet, UnicodeSet targetSet) {
UnicodeSet myFilter = getFilterAsUnicodeSet(inputFilter);
UnicodeSet temp = new UnicodeSet(handleGetSourceSet()).retainAll(myFilter);
// use old method, if we don't have anything better
sourceSet.addAll(temp);
// clumsy guess with target
for (String s : temp) {
String t = transliterate(s);
if (!s.equals(t)) {
targetSet.addAll(t);
}
}
}
/**
* Returns the intersectionof this instance's filter intersected with an external filter. The
* externalFilter must be frozen (it is frozen if not). The result may be frozen, so don't
* attempt to modify.
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
// TODO change to getMergedFilter
public UnicodeSet getFilterAsUnicodeSet(UnicodeSet externalFilter) {
if (filter == null) {
return externalFilter;
}
UnicodeSet filterSet = new UnicodeSet(externalFilter);
// Most, but not all filters will be UnicodeSets. Optimize for
// the high-runner case.
UnicodeSet temp;
try {
temp = filter;
} catch (ClassCastException e) {
filter.addMatchSetTo(temp = new UnicodeSet());
}
return filterSet.retainAll(temp).freeze();
}
/**
* Returns this transliterator's inverse. See the class documentation for details. This
* implementation simply inverts the two entities in the ID and attempts to retrieve the
* resulting transliterator. That is, if <code>getID()</code> returns "A-B", then this method
* will return the result of <code>getInstance("B-A")</code>, or <code>null</code> if that call
* fails.
*
* <p>Subclasses with knowledge of their inverse may wish to override this method.
*
* @return a transliterator that is an inverse, not necessarily exact, of this transliterator,
* or <code>null</code> if no such transliterator is registered.
* @see #registerClass
* @stable ICU 2.0
*/
public final Transliterator getInverse() {
return getInstance(ID, REVERSE);
}
/**
* Registers a subclass of <code>Transliterator</code> with the system. This subclass must have
* a public constructor taking no arguments. When that constructor is called, the resulting
* object must return the <code>ID</code> passed to this method if its <code>getID()</code>
* method is called.
*
* @param ID the result of <code>getID()</code> for this transliterator
* @param transClass a subclass of <code>Transliterator</code>
* @see #unregister
* @stable ICU 2.0
*/
public static void registerClass(
String ID, Class<? extends Transliterator> transClass, String displayName) {
registry.put(ID, transClass, true);
if (displayName != null) {
displayNameCache.put(new CaseInsensitiveString(ID), displayName);
}
}
/**
* Register a factory object with the given ID. The factory method should return a new instance
* of the given transliterator.
*
* <p>Because ICU may choose to cache Transliterator objects internally, this must be called at
* application startup, prior to any calls to Transliterator.getInstance to avoid undefined
* behavior.
*
* @param ID the ID of this transliterator
* @param factory the factory object
* @stable ICU 2.0
*/
public static void registerFactory(String ID, Factory factory) {
registry.put(ID, factory, true);
}
/**
* Register a Transliterator object with the given ID.
*
* <p>Because ICU may choose to cache Transliterator objects internally, this must be called at
* application startup, prior to any calls to Transliterator.getInstance to avoid undefined
* behavior.
*
* @param trans the Transliterator object
* @stable ICU 2.2
*/
public static void registerInstance(Transliterator trans) {
registry.put(trans.getID(), trans, true);
}
/**
* Register a Transliterator object.
*
* <p>Because ICU may choose to cache Transliterator objects internally, this must be called at
* application startup, prior to any calls to Transliterator.getInstance to avoid undefined
* behavior.
*
* @param trans the Transliterator object
*/
static void registerInstance(Transliterator trans, boolean visible) {
registry.put(trans.getID(), trans, visible);
}
/**
* Register an ID as an alias of another ID. Instantiating alias ID produces the same result as
* instantiating the original ID. This is generally used to create short aliases of compound
* IDs.
*
* <p>Because ICU may choose to cache Transliterator objects internally, this must be called at
* application startup, prior to any calls to Transliterator.getInstance to avoid undefined
* behavior.
*
* @param aliasID The new ID being registered.
* @param realID The existing ID that the new ID should be an alias of.
* @stable ICU 3.6
*/
public static void registerAlias(String aliasID, String realID) {
registry.put(aliasID, realID, true);
}
/**
* Register two targets as being inverses of one another. For example, calling
* registerSpecialInverse("NFC", "NFD", true) causes Transliterator to form the following
* inverse relationships:
*
* <pre>NFC => NFD
* Any-NFC => Any-NFD
* NFD => NFC
* Any-NFD => Any-NFC</pre>
*
* (Without the special inverse registration, the inverse of NFC would be NFC-Any.) Note that
* NFD is shorthand for Any-NFD, but that the presence or absence of "Any-" is preserved.
*
* <p>The relationship is symmetrical; registering (a, b) is equivalent to registering (b, a).
*
* <p>The relevant IDs must still be registered separately as factories or classes.
*
* <p>Only the targets are specified. Special inverses always have the form Any-Target1
* <=> Any-Target2. The target should have canonical casing (the casing desired to be
* produced when an inverse is formed) and should contain no whitespace or other extraneous
* characters.
*
* @param target the target against which to register the inverse
* @param inverseTarget the inverse of target, that is Any-target.getInverse() =>
* Any-inverseTarget
* @param bidirectional if true, register the reverse relation as well, that is,
* Any-inverseTarget.getInverse() => Any-target
*/
static void registerSpecialInverse(String target, String inverseTarget, boolean bidirectional) {
TransliteratorIDParser.registerSpecialInverse(target, inverseTarget, bidirectional);
}
/**
* Unregisters a transliterator or class. This may be either a system transliterator or a user
* transliterator or class.
*
* @param ID the ID of the transliterator or class
* @see #registerClass
* @stable ICU 2.0
*/
public static void unregister(String ID) {
displayNameCache.remove(new CaseInsensitiveString(ID));
registry.remove(ID);
}
/**
* Returns an enumeration over the programmatic names of registered <code>Transliterator</code>
* objects. This includes both system transliterators and user transliterators registered using
* <code>registerClass()</code>. The enumerated names may be passed to <code>getInstance()
* </code>.
*
* @return An <code>Enumeration</code> over <code>String</code> objects
* @see #getInstance
* @see #registerClass
* @stable ICU 2.0
*/
public static final Enumeration<String> getAvailableIDs() {
return registry.getAvailableIDs();
}
/**
* Returns an enumeration over the source names of registered transliterators. Source names may
* be passed to getAvailableTargets() to obtain available targets for each source.
*
* @stable ICU 2.0
*/
public static final Enumeration<String> getAvailableSources() {
return registry.getAvailableSources();
}
/**
* Returns an enumeration over the target names of registered transliterators having a given
* source name. Target names may be passed to getAvailableVariants() to obtain available
* variants for each source and target pair.
*
* @stable ICU 2.0
*/
public static final Enumeration<String> getAvailableTargets(String source) {
return registry.getAvailableTargets(source);
}
/**
* Returns an enumeration over the variant names of registered transliterators having a given
* source name and target name.
*
* @stable ICU 2.0
*/
public static final Enumeration<String> getAvailableVariants(String source, String target) {
return registry.getAvailableVariants(source, target);
}
private static final String ROOT = "root", RB_RULE_BASED_IDS = "RuleBasedTransliteratorIDs";
static {
registry = new TransliteratorRegistry();
// The display name cache starts out empty
displayNameCache =
Collections.synchronizedMap(new HashMap<CaseInsensitiveString, String>());
/* The following code parses the index table located in
* icu/data/translit/root.txt. The index is an n x 4 table
* that follows this format:
* <id>{
* file{
* resource{"<resource>"}
* direction{"<direction>"}
* }
* }
* <id>{
* internal{
* resource{"<resource>"}
* direction{"<direction"}
* }
* }
* <id>{
* alias{"<getInstanceArg"}
* }
* <id> is the ID of the system transliterator being defined. These
* are public IDs enumerated by Transliterator.getAvailableIDs(),
* unless the second field is "internal".
*
* <resource> is a ResourceReader resource name. Currently these refer
* to file names under com/ibm/text/resources. This string is passed
* directly to ResourceReader, together with <encoding>.
*
* <direction> is either "FORWARD" or "REVERSE".
*
* <getInstanceArg> is a string to be passed directly to
* Transliterator.getInstance(). The returned Transliterator object
* then has its ID changed to <id> and is returned.
*
* The extra blank field on "alias" lines is to make the array square.
*/
UResourceBundle bundle, transIDs, colBund;
bundle = UResourceBundle.getBundleInstance(ICUData.ICU_TRANSLIT_BASE_NAME, ROOT);
transIDs = bundle.get(RB_RULE_BASED_IDS);
int row, maxRows;
maxRows = transIDs.getSize();
for (row = 0; row < maxRows; row++) {
colBund = transIDs.get(row);
String ID = colBund.getKey();
if (ID.indexOf("-t-") >= 0) {
continue;
}
UResourceBundle res = colBund.get(0);
String type = res.getKey();
if (type.equals("file") || type.equals("internal")) {
// Rest of line is <resource>:<encoding>:<direction>
// pos colon c2
int rowIndex = row;
Supplier<String> resSupplier =
() -> {
// Capture the row Id instead of the UResourceBundle object
// due to the memory cost.
UResourceBundle rootBund =
UResourceBundle.getBundleInstance(
ICUData.ICU_TRANSLIT_BASE_NAME, ROOT);
UResourceBundle transIDsBund = rootBund.get(RB_RULE_BASED_IDS);
UResourceBundle thisBund = transIDsBund.get(rowIndex).get(0);
return thisBund.getString("resource");
};
int dir;
String direction = res.getString("direction");
switch (direction.charAt(0)) {
case 'F':
dir = FORWARD;
break;
case 'R':
dir = REVERSE;
break;
default:
throw new RuntimeException("Can't parse direction: " + direction);
}
registry.put(
ID,
resSupplier, // resource
dir,
!type.equals("internal"));
} else if (type.equals("alias")) {
// 'alias'; row[2]=createInstance argument
String resString = res.getString();
registry.put(ID, resString, true);
} else {
// Unknown type
throw new RuntimeException("Unknown type: " + type);
}
}
registerSpecialInverse(NullTransliterator.SHORT_ID, NullTransliterator.SHORT_ID, false);
// Register non-rule-based transliterators
registerClass(NullTransliterator._ID, NullTransliterator.class, null);
RemoveTransliterator.register();
EscapeTransliterator.register();
UnescapeTransliterator.register();
LowercaseTransliterator.register();
UppercaseTransliterator.register();
TitlecaseTransliterator.register();
CaseFoldTransliterator.register();
UnicodeNameTransliterator.register();
NameUnicodeTransliterator.register();
NormalizationTransliterator.register();
BreakTransliterator.register();
AnyTransliterator.register(); // do this last!
}
/**
* Register the script-based "Any" transliterators: Any-Latin, Any-Greek
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public static void registerAny() {
AnyTransliterator.register();
}
/**
* The factory interface for transliterators. Transliterator subclasses can register factory
* objects for IDs using the registerFactory() method of Transliterator. When invoked, the
* factory object will be passed the ID being instantiated. This makes it possible to register
* one factory method to more than one ID, or for a factory method to parameterize its result
* based on the variant.
*
* @stable ICU 2.0
*/
public static interface Factory {
/**
* Return a transliterator for the given ID.
*
* @stable ICU 2.0
*/
Transliterator getInstance(String ID);
}
/**
* Implements StringTransform via this method.
*
* @param source text to be transformed (eg lowercased)
* @return result
* @stable ICU 3.8
*/
@Override
public String transform(String source) {
return transliterate(source);
}
}