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      1 /*
      2 *******************************************************************************
      3 *   Copyright (C) 2011, International Business Machines
      4 *   Corporation and others.  All Rights Reserved.
      5 *******************************************************************************
      6 *   file name:  patternprops.cpp
      7 *   encoding:   US-ASCII
      8 *   tab size:   8 (not used)
      9 *   indentation:4
     10 *
     11 *   created on: 2011mar13
     12 *   created by: Markus W. Scherer
     13 */
     14 
     15 #include "unicode/utypes.h"
     16 #include "patternprops.h"
     17 
     18 U_NAMESPACE_BEGIN
     19 
     20 /*
     21  * One byte per Latin-1 character.
     22  * Bit 0 is set if either Pattern property is true,
     23  * bit 1 if Pattern_Syntax is true,
     24  * bit 2 if Pattern_White_Space is true.
     25  * That is, Pattern_Syntax is encoded as 3 and Pattern_White_Space as 5.
     26  */
     27 static const uint8_t latin1[256]={
     28     // WS: 9..D
     29     0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 5, 5, 5, 5, 0, 0,
     30     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     31     // WS: 20  Syntax: 21..2F
     32     5, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
     33     // Syntax: 3A..40
     34     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3,
     35     3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     36     // Syntax: 5B..5E
     37     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 0,
     38     // Syntax: 60
     39     3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     40     // Syntax: 7B..7E
     41     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 0,
     42     // WS: 85
     43     0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     44     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     45     // Syntax: A1..A7, A9, AB, AC, AE
     46     0, 3, 3, 3, 3, 3, 3, 3, 0, 3, 0, 3, 3, 0, 3, 0,
     47     // Syntax: B0, B1, B6, BB, BF
     48     3, 3, 0, 0, 0, 0, 3, 0, 0, 0, 0, 3, 0, 0, 0, 3,
     49     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     50     // Syntax: D7
     51     0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0,
     52     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     53     // Syntax: F7
     54     0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0
     55 };
     56 
     57 /*
     58  * One byte per 32 characters from U+2000..U+303F indexing into
     59  * a small table of 32-bit data words.
     60  * The first two data words are all-zeros and all-ones.
     61  */
     62 static const uint8_t index2000[130]={
     63     2, 3, 4, 0, 0, 0, 0, 0,  // 20xx
     64     0, 0, 0, 0, 5, 1, 1, 1,  // 21xx
     65     1, 1, 1, 1, 1, 1, 1, 1,  // 22xx
     66     1, 1, 1, 1, 1, 1, 1, 1,  // 23xx
     67     1, 1, 1, 0, 0, 0, 0, 0,  // 24xx
     68     1, 1, 1, 1, 1, 1, 1, 1,  // 25xx
     69     1, 1, 1, 1, 1, 1, 1, 1,  // 26xx
     70     1, 1, 1, 6, 7, 1, 1, 1,  // 27xx
     71     1, 1, 1, 1, 1, 1, 1, 1,  // 28xx
     72     1, 1, 1, 1, 1, 1, 1, 1,  // 29xx
     73     1, 1, 1, 1, 1, 1, 1, 1,  // 2Axx
     74     1, 1, 1, 1, 1, 1, 1, 1,  // 2Bxx
     75     0, 0, 0, 0, 0, 0, 0, 0,  // 2Cxx
     76     0, 0, 0, 0, 0, 0, 0, 0,  // 2Dxx
     77     1, 1, 1, 1, 0, 0, 0, 0,  // 2Exx
     78     0, 0, 0, 0, 0, 0, 0, 0,  // 2Fxx
     79     8, 9  // 3000..303F
     80 };
     81 
     82 /*
     83  * One 32-bit integer per 32 characters. Ranges of all-false and all-true
     84  * are mapped to the first two values, other ranges map to appropriate bit patterns.
     85  */
     86 static const uint32_t syntax2000[]={
     87     0,
     88     0xffffffff,
     89     0xffff0000,  // 2: 2010..201F
     90     0x7fff00ff,  // 3: 2020..2027, 2030..203E
     91     0x7feffffe,  // 4: 2041..2053, 2055..205E
     92     0xffff0000,  // 5: 2190..219F
     93     0x003fffff,  // 6: 2760..2775
     94     0xfff00000,  // 7: 2794..279F
     95     0xffffff0e,  // 8: 3001..3003, 3008..301F
     96     0x00010001   // 9: 3020, 3030
     97 };
     98 
     99 /*
    100  * Same as syntax2000, but with additional bits set for the
    101  * Pattern_White_Space characters 200E 200F 2028 2029.
    102  */
    103 static const uint32_t syntaxOrWhiteSpace2000[]={
    104     0,
    105     0xffffffff,
    106     0xffffc000,  // 2: 200E..201F
    107     0x7fff03ff,  // 3: 2020..2029, 2030..203E
    108     0x7feffffe,  // 4: 2041..2053, 2055..205E
    109     0xffff0000,  // 5: 2190..219F
    110     0x003fffff,  // 6: 2760..2775
    111     0xfff00000,  // 7: 2794..279F
    112     0xffffff0e,  // 8: 3001..3003, 3008..301F
    113     0x00010001   // 9: 3020, 3030
    114 };
    115 
    116 UBool
    117 PatternProps::isSyntax(UChar32 c) {
    118     if(c<0) {
    119         return FALSE;
    120     } else if(c<=0xff) {
    121         return (UBool)(latin1[c]>>1)&1;
    122     } else if(c<0x2010) {
    123         return FALSE;
    124     } else if(c<=0x3030) {
    125         uint32_t bits=syntax2000[index2000[(c-0x2000)>>5]];
    126         return (UBool)((bits>>(c&0x1f))&1);
    127     } else if(0xfd3e<=c && c<=0xfe46) {
    128         return c<=0xfd3f || 0xfe45<=c;
    129     } else {
    130         return FALSE;
    131     }
    132 }
    133 
    134 UBool
    135 PatternProps::isSyntaxOrWhiteSpace(UChar32 c) {
    136     if(c<0) {
    137         return FALSE;
    138     } else if(c<=0xff) {
    139         return (UBool)(latin1[c]&1);
    140     } else if(c<0x200e) {
    141         return FALSE;
    142     } else if(c<=0x3030) {
    143         uint32_t bits=syntaxOrWhiteSpace2000[index2000[(c-0x2000)>>5]];
    144         return (UBool)((bits>>(c&0x1f))&1);
    145     } else if(0xfd3e<=c && c<=0xfe46) {
    146         return c<=0xfd3f || 0xfe45<=c;
    147     } else {
    148         return FALSE;
    149     }
    150 }
    151 
    152 UBool
    153 PatternProps::isWhiteSpace(UChar32 c) {
    154     if(c<0) {
    155         return FALSE;
    156     } else if(c<=0xff) {
    157         return (UBool)(latin1[c]>>2)&1;
    158     } else if(0x200e<=c && c<=0x2029) {
    159         return c<=0x200f || 0x2028<=c;
    160     } else {
    161         return FALSE;
    162     }
    163 }
    164 
    165 const UChar *
    166 PatternProps::skipWhiteSpace(const UChar *s, int32_t length) {
    167     while(length>0 && isWhiteSpace(*s)) {
    168         ++s;
    169         --length;
    170     }
    171     return s;
    172 }
    173 
    174 const UChar *
    175 PatternProps::trimWhiteSpace(const UChar *s, int32_t &length) {
    176     if(length<=0 || (!isWhiteSpace(s[0]) && !isWhiteSpace(s[length-1]))) {
    177         return s;
    178     }
    179     int32_t start=0;
    180     int32_t limit=length;
    181     while(start<limit && isWhiteSpace(s[start])) {
    182         ++start;
    183     }
    184     if(start<limit) {
    185         // There is non-white space at start; we will not move limit below that,
    186         // so we need not test start<limit in the loop.
    187         while(isWhiteSpace(s[limit-1])) {
    188             --limit;
    189         }
    190     }
    191     length=limit-start;
    192     return s+start;
    193 }
    194 
    195 UBool
    196 PatternProps::isIdentifier(const UChar *s, int32_t length) {
    197     if(length<=0) {
    198         return FALSE;
    199     }
    200     const UChar *limit=s+length;
    201     do {
    202         if(isSyntaxOrWhiteSpace(*s++)) {
    203             return FALSE;
    204         }
    205     } while(s<limit);
    206     return TRUE;
    207 }
    208 
    209 const UChar *
    210 PatternProps::skipIdentifier(const UChar *s, int32_t length) {
    211     while(length>0 && !isSyntaxOrWhiteSpace(*s)) {
    212         ++s;
    213         --length;
    214     }
    215     return s;
    216 }
    217 
    218 U_NAMESPACE_END
    219