1 /*
2 *******************************************************************************
3 *   Copyright (C) 2011, International Business Machines
4 *   Corporation and others.  All Rights Reserved.
5 *******************************************************************************
6 *   created on: 2011feb25
7 *   created by: Markus W. Scherer
8 */
9 
10 package com.ibm.icu.impl;
11 
12 /**
13  * Implements the immutable Unicode properties Pattern_Syntax and Pattern_White_Space.
14  * Hardcodes these properties, does not load data, does not depend on other ICU classes.
15  * <p>
16  * Note: Both properties include ASCII as well as non-ASCII, non-Latin-1 code points,
17  * and both properties only include BMP code points (no supplementary ones).
18  * Pattern_Syntax includes some unassigned code points.
19  * <p>
20  * [:Pattern_White_Space:] =
21  *   [\u0009-\u000D\ \u0085\u200E\u200F\u2028\u2029]
22  * <p>
23  * [:Pattern_Syntax:] =
24  *   [!-/\:-@\[-\^`\{-~\u00A1-\u00A7\u00A9\u00AB\u00AC\u00AE
25  *    \u00B0\u00B1\u00B6\u00BB\u00BF\u00D7\u00F7
26  *    \u2010-\u2027\u2030-\u203E\u2041-\u2053\u2055-\u205E
27  *    \u2190-\u245F\u2500-\u2775\u2794-\u2BFF\u2E00-\u2E7F
28  *    \u3001-\u3003\u3008-\u3020\u3030\uFD3E\uFD3F\uFE45\uFE46]
29  * @author mscherer
30  */
31 public final class PatternProps {
32     /**
33      * @return true if c is a Pattern_Syntax code point.
34      */
isSyntax(int c)35     public static boolean isSyntax(int c) {
36         if(c<0) {
37             return false;
38         } else if(c<=0xff) {
39             return latin1[c]==3;
40         } else if(c<0x2010) {
41             return false;
42         } else if(c<=0x3030) {
43             int bits=syntax2000[index2000[(c-0x2000)>>5]];
44             return ((bits>>(c&0x1f))&1)!=0;
45         } else if(0xfd3e<=c && c<=0xfe46) {
46             return c<=0xfd3f || 0xfe45<=c;
47         } else {
48             return false;
49         }
50     }
51 
52     /**
53      * @return true if c is a Pattern_Syntax or Pattern_White_Space code point.
54      */
isSyntaxOrWhiteSpace(int c)55     public static boolean isSyntaxOrWhiteSpace(int c) {
56         if(c<0) {
57             return false;
58         } else if(c<=0xff) {
59             return latin1[c]!=0;
60         } else if(c<0x200e) {
61             return false;
62         } else if(c<=0x3030) {
63             int bits=syntaxOrWhiteSpace2000[index2000[(c-0x2000)>>5]];
64             return ((bits>>(c&0x1f))&1)!=0;
65         } else if(0xfd3e<=c && c<=0xfe46) {
66             return c<=0xfd3f || 0xfe45<=c;
67         } else {
68             return false;
69         }
70     }
71 
72     /**
73      * @return true if c is a Pattern_White_Space character.
74      */
isWhiteSpace(int c)75     public static boolean isWhiteSpace(int c) {
76         if(c<0) {
77             return false;
78         } else if(c<=0xff) {
79             return latin1[c]==5;
80         } else if(0x200e<=c && c<=0x2029) {
81             return c<=0x200f || 0x2028<=c;
82         } else {
83             return false;
84         }
85     }
86 
87     /**
88      * Skips over Pattern_White_Space starting at index i of the CharSequence.
89      * @return The smallest index at or after i with a non-white space character.
90      */
skipWhiteSpace(CharSequence s, int i)91     public static int skipWhiteSpace(CharSequence s, int i) {
92         while(i<s.length() && isWhiteSpace(s.charAt(i))) {
93             ++i;
94         }
95         return i;
96     }
97 
98     /**
99      * @return s except with leading and trailing Pattern_White_Space removed.
100      */
trimWhiteSpace(String s)101     public static String trimWhiteSpace(String s) {
102         if(s.length()==0 || (!isWhiteSpace(s.charAt(0)) && !isWhiteSpace(s.charAt(s.length()-1)))) {
103             return s;
104         }
105         int start=0;
106         int limit=s.length();
107         while(start<limit && isWhiteSpace(s.charAt(start))) {
108             ++start;
109         }
110         if(start<limit) {
111             // There is non-white space at start; we will not move limit below that,
112             // so we need not test start<limit in the loop.
113             while(isWhiteSpace(s.charAt(limit-1))) {
114                 --limit;
115             }
116         }
117         return s.substring(start, limit);
118     }
119 
120     /**
121      * Tests whether the CharSequence contains a "pattern identifier", that is,
122      * whether it contains only non-Pattern_White_Space, non-Pattern_Syntax characters.
123      * @return true if there are no Pattern_White_Space or Pattern_Syntax characters in s.
124      */
isIdentifier(CharSequence s)125     public static boolean isIdentifier(CharSequence s) {
126         int limit=s.length();
127         if(limit==0) {
128             return false;
129         }
130         int start=0;
131         do {
132             if(isSyntaxOrWhiteSpace(s.charAt(start++))) {
133                 return false;
134             }
135         } while(start<limit);
136         return true;
137     }
138 
139     /**
140      * Tests whether the CharSequence contains a "pattern identifier", that is,
141      * whether it contains only non-Pattern_White_Space, non-Pattern_Syntax characters.
142      * @return true if there are no Pattern_White_Space or Pattern_Syntax characters
143      *         in s between start and (exclusive) limit.
144      */
isIdentifier(CharSequence s, int start, int limit)145     public static boolean isIdentifier(CharSequence s, int start, int limit) {
146         if(start>=limit) {
147             return false;
148         }
149         do {
150             if(isSyntaxOrWhiteSpace(s.charAt(start++))) {
151                 return false;
152             }
153         } while(start<limit);
154         return true;
155     }
156 
157     /**
158      * Skips over a "pattern identifier" starting at index i of the CharSequence.
159      * @return The smallest index at or after i with
160      *         a Pattern_White_Space or Pattern_Syntax character.
161      */
skipIdentifier(CharSequence s, int i)162     public static int skipIdentifier(CharSequence s, int i) {
163         while(i<s.length() && !isSyntaxOrWhiteSpace(s.charAt(i))) {
164             ++i;
165         }
166         return i;
167     }
168 
169     /*
170      * One byte per Latin-1 character.
171      * Bit 0 is set if either Pattern property is true,
172      * bit 1 if Pattern_Syntax is true,
173      * bit 2 if Pattern_White_Space is true.
174      * That is, Pattern_Syntax is encoded as 3 and Pattern_White_Space as 5.
175      */
176     private static final byte latin1[]=new byte[] {  // 256
177         // WS: 9..D
178         0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 5, 5, 5, 5, 0, 0,
179         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
180         // WS: 20  Syntax: 21..2F
181         5, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
182         // Syntax: 3A..40
183         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3,
184         3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
185         // Syntax: 5B..5E
186         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 0,
187         // Syntax: 60
188         3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
189         // Syntax: 7B..7E
190         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 0,
191         // WS: 85
192         0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
193         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
194         // Syntax: A1..A7, A9, AB, AC, AE
195         0, 3, 3, 3, 3, 3, 3, 3, 0, 3, 0, 3, 3, 0, 3, 0,
196         // Syntax: B0, B1, B6, BB, BF
197         3, 3, 0, 0, 0, 0, 3, 0, 0, 0, 0, 3, 0, 0, 0, 3,
198         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
199         // Syntax: D7
200         0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0,
201         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
202         // Syntax: F7
203         0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0
204     };
205 
206     /*
207      * One byte per 32 characters from U+2000..U+303F indexing into
208      * a small table of 32-bit data words.
209      * The first two data words are all-zeros and all-ones.
210      */
211     private static final byte index2000[]=new byte[] {  // 130
212         2, 3, 4, 0, 0, 0, 0, 0,  // 20xx
213         0, 0, 0, 0, 5, 1, 1, 1,  // 21xx
214         1, 1, 1, 1, 1, 1, 1, 1,  // 22xx
215         1, 1, 1, 1, 1, 1, 1, 1,  // 23xx
216         1, 1, 1, 0, 0, 0, 0, 0,  // 24xx
217         1, 1, 1, 1, 1, 1, 1, 1,  // 25xx
218         1, 1, 1, 1, 1, 1, 1, 1,  // 26xx
219         1, 1, 1, 6, 7, 1, 1, 1,  // 27xx
220         1, 1, 1, 1, 1, 1, 1, 1,  // 28xx
221         1, 1, 1, 1, 1, 1, 1, 1,  // 29xx
222         1, 1, 1, 1, 1, 1, 1, 1,  // 2Axx
223         1, 1, 1, 1, 1, 1, 1, 1,  // 2Bxx
224         0, 0, 0, 0, 0, 0, 0, 0,  // 2Cxx
225         0, 0, 0, 0, 0, 0, 0, 0,  // 2Dxx
226         1, 1, 1, 1, 0, 0, 0, 0,  // 2Exx
227         0, 0, 0, 0, 0, 0, 0, 0,  // 2Fxx
228         8, 9  // 3000..303F
229     };
230 
231     /*
232      * One 32-bit integer per 32 characters. Ranges of all-false and all-true
233      * are mapped to the first two values, other ranges map to appropriate bit patterns.
234      */
235     private static final int syntax2000[]=new int[] {
236         0,
237         -1,
238         0xffff0000,  // 2: 2010..201F
239         0x7fff00ff,  // 3: 2020..2027, 2030..203E
240         0x7feffffe,  // 4: 2041..2053, 2055..205E
241         0xffff0000,  // 5: 2190..219F
242         0x003fffff,  // 6: 2760..2775
243         0xfff00000,  // 7: 2794..279F
244         0xffffff0e,  // 8: 3001..3003, 3008..301F
245         0x00010001   // 9: 3020, 3030
246     };
247 
248     /*
249      * Same as syntax2000, but with additional bits set for the
250      * Pattern_White_Space characters 200E 200F 2028 2029.
251      */
252     private static final int syntaxOrWhiteSpace2000[]=new int[] {
253         0,
254         -1,
255         0xffffc000,  // 2: 200E..201F
256         0x7fff03ff,  // 3: 2020..2029, 2030..203E
257         0x7feffffe,  // 4: 2041..2053, 2055..205E
258         0xffff0000,  // 5: 2190..219F
259         0x003fffff,  // 6: 2760..2775
260         0xfff00000,  // 7: 2794..279F
261         0xffffff0e,  // 8: 3001..3003, 3008..301F
262         0x00010001   // 9: 3020, 3030
263     };
264 }
265