a42347b224
characters, for example. Normalization forms NFKD and NFD are supported for the Tibetan Unicode range. I don't like either, actually. I've tested NFKD, but I've not yet committed the tests.
276 lines
12 KiB
Java
276 lines
12 KiB
Java
/*
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The contents of this file are subject to the THDL Open Community License
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Version 1.0 (the "License"); you may not use this file except in compliance
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with the License. You may obtain a copy of the License on the THDL web site
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(http://www.thdl.org/).
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Software distributed under the License is distributed on an "AS IS" basis,
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WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
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License for the specific terms governing rights and limitations under the
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License.
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The Initial Developer of this software is the Tibetan and Himalayan Digital
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Library (THDL). Portions created by the THDL are Copyright 2001 THDL.
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All Rights Reserved.
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Contributor(s): ______________________________________.
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*/
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package org.thdl.tib.text.tshegbar;
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/** <p>This non-instantiable class contains utility routines for
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* dealing with Tibetan Unicode codepoints and strings of such
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* codepoints.</p>
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*
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* @author David Chandler */
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public class UnicodeUtils implements UnicodeConstants {
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/** Do not use this, as this class is not instantiable. */
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private UnicodeUtils() { super(); }
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/** Returns true iff x is a Unicode codepoint that represents a
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consonant or two-consonant stack that has a Unicode code
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point. Returns true only for the usual suspects (like
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<code>\u0F40</code>) and for Sanskrit consonants (like
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<code>\u0F71</code>) and the simple two-consonant stacks in
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Unicode (like <code>\u0F43</code>). Returns false for, among
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other things, subjoined consonants like
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<code>\u0F90</code>. */
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public static boolean isNonSubjoinedConsonant(char x) {
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return ((x != '\u0F48' /* reserved in Unicode 3.2, but not in use */)
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&& (x >= '\u0F40' && x <= '\u0F6A'));
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}
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/** Returns true iff x is a Unicode codepoint that represents a
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subjoined consonant or subjoined two-consonant stack that has
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a Unicode code point. Returns true only for the usual
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suspects (like <code>\u0F90</code>) and for Sanskrit
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consonants (like <code>\u0F9C</code>) and the simple
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two-consonant stacks in Unicode (like <code>\u0FAC</code>).
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Returns false for, among other things, non-subjoined
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consonants like <code>\u0F40</code>. */
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public static boolean isSubjoinedConsonant(char x) {
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return ((x != '\u0F98' /* reserved in Unicode 3.2, but not in use */)
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&& (x >= '\u0F90' && x <= '\u0FBC'));
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}
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/** Returns true iff x is the preferred representation of a
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Tibetan or Sanskrit consonant and cannot be broken down any
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further. Returns false for, among other things, subjoined
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consonants like <code>\u0F90</code>, two-component consonants
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like <code>\u0F43</code>, and fixed-form consonants like
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'\u0F6A'. The new consonants (for transcribing Chinese, I
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believe) "\u0F55\u0F39" (which EWTS calls "fa"),
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"\u0F56\u0F39" ("va"), and "\u0F5F\u0F39" ("Dza") are
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two-codepoint sequences, but you should be aware of them
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also. */
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public static boolean isPreferredFormOfConsonant(char x) {
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return ((x != '\u0F48' /* reserved in Unicode 3.2, but not in use */)
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&& (x >= '\u0F40' && x <= '\u0F68')
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&& (x != '\u0F43')
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&& (x != '\u0F4D')
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&& (x != '\u0F52')
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&& (x != '\u0F57')
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&& (x != '\u0F5C'));
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}
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/** Returns true iff unicodeCP is a codepoint from the Unicode
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range U+0F00-U+0FFF.
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@see #isEntirelyTibetanUnicode(String) */
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public static boolean isInTibetanRange(char unicodeCP) {
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return (unicodeCP >= '\u0F00' && unicodeCP <= '\u0FFF');
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}
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/** Returns true iff unicodeString consists only of codepoints
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from the Unicode range U+0F00-U+0FFF. (Note that these
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codepoints are typically not enough to represent a Tibetan
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text, you may need ZWSP (zero-width space) and various
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whitespace from other ranges.) */
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public static boolean isEntirelyTibetanUnicode(String unicodeString) {
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for (int i = 0; i < unicodeString.length(); i++) {
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if (!isInTibetanRange(unicodeString.charAt(i)))
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return false;
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}
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return true;
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}
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/** Puts the Tibetan codepoints in tibetanUnicode, a sequence of
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Unicode codepoints, into Normalization Form KD (NFKD) as
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specified by Unicode 3.2. The Tibetan passages of the
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returned string are in NFKD, but codepoints outside of the
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range <code>U+0F00</code>-<code>U+0FFF</code> are not
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necessarily put into NFKD. This form uses a maximum of
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codepoints, and it never uses codepoints whose use has been
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{@link #isDiscouraged(char) discouraged}. It would be David
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Chandler's very favorite form if not for the fact that
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<code>U+0F0C</code> normalizes to <code>U+0F0B</code> in NFKD.
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NFD is thus David Chandler's favorite, though it does not
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decompose <code>U+0F77</code> and <code>U+0F79</code> (for
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some reason, hopefully a well-thought-out one).
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<p>Recall that NFKD, as it applies to Tibetan codepoints, is
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closed under string concatenation and under substringing.
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Note again that if the input contains codepoints for which
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{@link #isInTibetanRange(char)} is not true, then they will
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not be modified.</p>
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<p>Note well that only well-formed input guarantees
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well-formed output.</p>
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@param tibetanUnicode the codepoints to be decomposed
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@param normForm NORM_NFKD or NORM_NFD */
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public static void toMostlyDecomposedUnicode(StringBuffer tibetanUnicode,
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byte normForm)
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{
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if (normForm != NORM_NFD && normForm != NORM_NFKD)
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throw new IllegalArgumentException("normForm must be NORM_NFD or NORM_NFKD for decomposition to work");
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int offset = 0;
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while (offset < tibetanUnicode.length()) {
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String s
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= toNormalizedForm(tibetanUnicode.charAt(offset), normForm);
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if (null == s) {
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++offset;
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} else {
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// modify tibetanUnicode and update offset.
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tibetanUnicode.deleteCharAt(offset);
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tibetanUnicode.insert(offset, s);
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}
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}
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}
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/** Like {@link #toMostlyDecomposedUnicode(StringBuffer, byte)},
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but does not modify its input. Instead, it returns the NFKD-
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or NFD-normalized version of tibetanUnicode. */
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public static String toMostlyDecomposedUnicode(String tibetanUnicode,
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byte normForm)
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{
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StringBuffer sb = new StringBuffer(tibetanUnicode);
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toMostlyDecomposedUnicode(sb, normForm);
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return sb.toString();
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}
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/** There are 19 codepoints in the Tibetan range of Unicode 3.2
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which can be decomposed into longer strings of codepoints in
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the Tibetan range of Unicode. Often one wants to manipulate
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decomposed codepoint strings. Also, HTML and XML are W3C
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standards that require certain normalization forms. This
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routine returns a chosen normalized form for such codepoints,
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and returns null for codepoints that are already normalized or
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are not in the Tibetan range of Unicode.
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@param tibetanUnicodeCP the codepoint to normalize
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@param normalizationForm NORM_NFKD or NORM_NFD if you expect
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something nontrivial to happen
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@return null if tibetanUnicodeCP is already in the chosen
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normalized form, or a string of two or three codepoints
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otherwise */
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public static String toNormalizedForm(char tibetanUnicodeCP, byte normalizationForm) {
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if (normalizationForm == NORM_NFKD
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|| normalizationForm == NORM_NFD) {
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// Where not specified, the NFKD form is also the NFD form.
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switch (tibetanUnicodeCP) {
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case '\u0F0C': return ((normalizationForm == NORM_NFKD)
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? "\u0F0B" : null);
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case '\u0F43': return "\u0F42\u0FB7";
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case '\u0F4D': return "\u0F4C\u0FB7";
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case '\u0F52': return "\u0F51\u0FB7";
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case '\u0F57': return "\u0F56\u0FB7";
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case '\u0F5C': return "\u0F5B\u0FB7";
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case '\u0F69': return "\u0F40\u0FB5";
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case '\u0F73': return "\u0F71\u0F72";
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case '\u0F75': return "\u0F71\u0F74";
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case '\u0F76': return "\u0FB2\u0F80";
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// I do not understand why NFD does not decompose this codepoint:
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case '\u0F77': return ((normalizationForm == NORM_NFKD)
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? "\u0FB2\u0F71\u0F80" : null);
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case '\u0F78': return "\u0FB3\u0F80";
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// I do not understand why NFD does not decompose this codepoint:
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case '\u0F79': return ((normalizationForm == NORM_NFKD)
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? "\u0FB3\u0F71\u0F80" : null);
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case '\u0F81': return "\u0F71\u0F80";
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case '\u0F93': return "\u0F92\u0FB7";
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case '\u0F9D': return "\u0F9C\u0FB7";
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case '\u0FA2': return "\u0FA1\u0FB7";
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case '\u0FA7': return "\u0FA6\u0FB7";
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case '\u0FAC': return "\u0FAB\u0FB7";
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case '\u0FB9': return "\u0F90\u0FB5";
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default:
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return null;
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}
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}
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return null;
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}
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/** Returns true iff tibetanUnicodeCP {@link
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#isInTibetanRange(char) is a Tibetan codepoint} and if the
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Unicode 3.2 standard discourages the use of
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tibetanUnicodeCP. */
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public static boolean isDiscouraged(char tibetanUnicodeCP) {
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return ('\u0F73' == tibetanUnicodeCP
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|| '\u0F75' == tibetanUnicodeCP
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|| '\u0F77' == tibetanUnicodeCP
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|| '\u0F79' == tibetanUnicodeCP
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|| '\u0F81' == tibetanUnicodeCP);
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/* DLC FIXME -- I was using 3.0 p.437-440, check 3.2. */
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}
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/** Returns true iff ch corresponds to the Tibetan letter ra.
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Several Unicode codepoints correspond to the Tibetan letter ra
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(in its subscribed form or otherwise). Oftentimes,
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<code>\u0F62</code> is thought of as the nominal
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representation. Returns false for some codepoints that
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contain ra but are not merely ra, such as <code>\u0F77</code> */
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public static boolean isRa(char ch) {
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return ('\u0F62' == ch
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|| '\u0F6A' == ch
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|| '\u0FB2' == ch
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|| '\u0FBC' == ch);
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}
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/** Returns true iff ch corresponds to the Tibetan letter wa.
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Several Unicode codepoints correspond to the Tibetan letter
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wa. Oftentimes, <code>\u0F5D</code> is thought of as the
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nominal representation. */
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public static boolean isWa(char ch) {
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return ('\u0F5D' == ch
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|| '\u0FAD' == ch
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|| '\u0FBA' == ch);
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}
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/** Returns true iff ch corresponds to the Tibetan letter ya.
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Several Unicode codepoints correspond to the Tibetan letter
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ya. Oftentimes, <code>\u0F61</code> is thought of as the
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nominal representation. */
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public static boolean isYa(char ch) {
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return ('\u0F61' == ch
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|| '\u0FB1' == ch
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|| '\u0FBB' == ch);
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}
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/** Returns true iff there exists at least one codepoint cp in
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unicodeString such that cp {@link #isRa(char) is ra} or contains
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ra (like <code>\u0F77</code>). This method is not implemented
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as fast as it could be. It calls on the canonicalization code
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in order to maximize reuse and minimize the possibility of
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coder error. */
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public static boolean containsRa(String unicodeString) {
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String canonForm = toMostlyDecomposedUnicode(unicodeString, NORM_NFKD);
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for (int i = 0; i < canonForm.length(); i++) {
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if (isRa(canonForm.charAt(i)))
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return true;
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}
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return false;
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}
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/** Inefficient shortcut.
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@see #containsRa(String) */
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public static boolean containsRa(char unicodeCP) {
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return containsRa(new String(new char[] { unicodeCP }));
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}
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/** Returns a human-readable, ASCII form of the Unicode codepoint
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ch. */
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public static String unicodeCPToString(char ch) {
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return "U+" + Integer.toHexString((int)ch);
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}
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}
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