1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html#License
3/*
4**********************************************************************
5*   Copyright (c) 2002, International Business Machines Corporation
6*   and others.  All Rights Reserved.
7**********************************************************************
8*   Date        Name        Description
9*   01/14/2002  aliu        Creation.
10**********************************************************************
11*/
12
13package com.ibm.icu.text;
14
15/**
16 * <code>UnicodeReplacer</code> defines a protocol for objects that
17 * replace a range of characters in a Replaceable string with output
18 * text.  The replacement is done via the Replaceable API so as to
19 * preserve out-of-band data.
20 * @author Alan Liu
21 */
22interface UnicodeReplacer {
23
24    /**
25     * Replace characters in 'text' from 'start' to 'limit' with the
26     * output text of this object.  Update the 'cursor' parameter to
27     * give the cursor position and return the length of the
28     * replacement text.
29     *
30     * @param text the text to be matched
31     * @param start inclusive start index of text to be replaced
32     * @param limit exclusive end index of text to be replaced;
33     * must be greater than or equal to start
34     * @param cursor output parameter for the cursor position.
35     * Not all replacer objects will update this, but in a complete
36     * tree of replacer objects, representing the entire output side
37     * of a transliteration rule, at least one must update it.
38     * @return the number of 16-bit code units in the text replacing
39     * the characters at offsets start..(limit-1) in text
40     */
41    public abstract int replace(Replaceable text,
42                                int start,
43                                int limit,
44                                int[] cursor);
45
46    /**
47     * Returns a string representation of this replacer.  If the
48     * result of calling this function is passed to the appropriate
49     * parser, typically TransliteratorParser, it will produce another
50     * replacer that is equal to this one.
51     * @param escapeUnprintable if TRUE then convert unprintable
52     * character to their hex escape representations, \\uxxxx or
53     * \\Uxxxxxxxx.  Unprintable characters are defined by
54     * Utility.isUnprintable().
55     */
56    public abstract String toReplacerPattern(boolean escapeUnprintable);
57
58    /**
59     * Union the set of all characters that may output by this object
60     * into the given set.
61     * @param toUnionTo the set into which to union the output characters
62     */
63    public abstract void addReplacementSetTo(UnicodeSet toUnionTo);
64}
65
66//eof
67