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* accompanied this code).
*
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package java.util.regex;
final class Grapheme {
/**
* Determines if there is an extended grapheme cluster boundary between two
* continuing characters {@code cp1} and {@code cp2}.
* <p>
* See Unicode Standard Annex #29 Unicode Text Segmentation for the specification
* for the extended grapheme cluster boundary rules
*/
static boolean isBoundary(int cp1, int cp2) {
return rules[getType(cp1)][getType(cp2)];
}
// types
private static final int OTHER = 0;
private static final int CR = 1;
private static final int LF = 2;
private static final int CONTROL = 3;
private static final int EXTEND = 4;
private static final int RI = 5;
private static final int PREPEND = 6;
private static final int SPACINGMARK = 7;
private static final int L = 8;
private static final int V = 9;
private static final int T = 10;
private static final int LV = 11;
private static final int LVT = 12;
private static final int FIRST_TYPE = 0;
private static final int LAST_TYPE = 12;
private static boolean[][] rules;
static {
rules = new boolean[LAST_TYPE + 1][LAST_TYPE + 1];
// default, any + any
for (int i = FIRST_TYPE; i <= LAST_TYPE; i++)
for (int j = FIRST_TYPE; j <= LAST_TYPE; j++)
rules[i][j] = true;
// GB 6 L x (L | V | LV | VT)
rules[L][L] = false;
rules[L][V] = false;
rules[L][LV] = false;
rules[L][LVT] = false;
// GB 7 (LV | V) x (V | T)
rules[LV][V] = false;
rules[LV][T] = false;
rules[V][V] = false;
rules[V][T] = false;
// GB 8 (LVT | T) x T
rules[LVT][T] = false;
rules[T][T] = false;
// GB 8a RI x RI
rules[RI][RI] = false;
// GB 9 x Extend
// GB 9a x Spacing Mark
// GB 9b Prepend x
for (int i = FIRST_TYPE; i <= LAST_TYPE; i++) {
rules[i][EXTEND] = false;
rules[i][SPACINGMARK] = false;
rules[PREPEND][i] = false;
}
// GB 4 (Control | CR | LF) +
// GB 5 + (Control | CR | LF)
for (int i = FIRST_TYPE; i <= LAST_TYPE; i++)
for (int j = CR; j <= CONTROL; j++) {
rules[i][j] = true;
rules[j][i] = true;
}
// GB 3 CR x LF
rules[CR][LF] = false;
// GB 10 Any + Any -> default
}
// Hangul syllables
private static final int SYLLABLE_BASE = 0xAC00;
private static final int LCOUNT = 19;
private static final int VCOUNT = 21;
private static final int TCOUNT = 28;
private static final int NCOUNT = VCOUNT * TCOUNT; // 588
private static final int SCOUNT = LCOUNT * NCOUNT; // 11172
// #tr29: SpacingMark exceptions: The following (which have
// General_Category = Spacing_Mark and would otherwise be included)
// are specifically excluded
private static boolean isExcludedSpacingMark(int cp) {
return cp == 0x102B || cp == 0x102C || cp == 0x1038 ||
cp >= 0x1062 && cp <= 0x1064 ||
cp >= 0x1062 && cp <= 0x106D ||
cp == 0x1083 ||
cp >= 0x1087 && cp <= 0x108C ||
cp == 0x108F ||
cp >= 0x109A && cp <= 0x109C ||
cp == 0x1A61 || cp == 0x1A63 || cp == 0x1A64 ||
cp == 0xAA7B || cp == 0xAA7D;
}
@SuppressWarnings("fallthrough")
private static int getType(int cp) {
int type = Character.getType(cp);
switch(type) {
case Character.CONTROL:
if (cp == 0x000D)
return CR;
if (cp == 0x000A)
return LF;
return CONTROL;
case Character.UNASSIGNED:
// NOTE: #tr29 lists "Unassigned and Default_Ignorable_Code_Point" as Control
// but GraphemeBreakTest.txt lists u+0378/reserved-0378 as "Other"
// so type it as "Other" to make the test happy
if (cp == 0x0378)
return OTHER;
case Character.LINE_SEPARATOR:
case Character.PARAGRAPH_SEPARATOR:
case Character.SURROGATE:
return CONTROL;
case Character.FORMAT:
if (cp == 0x200C || cp == 0x200D)
return EXTEND;
return CONTROL;
case Character.NON_SPACING_MARK:
case Character.ENCLOSING_MARK:
// NOTE:
// #tr29 "plus a few General_Category = Spacing_Mark needed for
// canonical equivalence."
// but for "extended grapheme clusters" support, there is no
// need actually to diff "extend" and "spackmark" given GB9, GB9a
return EXTEND;
case Character.COMBINING_SPACING_MARK:
if (isExcludedSpacingMark(cp))
return OTHER;
// NOTE:
// 0x11720 and 0x11721 are mentioned in #tr29 as
// OTHER_LETTER but it appears their category has been updated to
// COMBING_SPACING_MARK already (verified in ver.8)
return SPACINGMARK;
case Character.OTHER_SYMBOL:
if (cp >= 0x1F1E6 && cp <= 0x1F1FF)
return RI;
return OTHER;
case Character.MODIFIER_LETTER:
// WARNING:
// not mentioned in #tr29 but listed in GraphemeBreakProperty.txt
if (cp == 0xFF9E || cp == 0xFF9F)
return EXTEND;
return OTHER;
case Character.OTHER_LETTER:
if (cp == 0x0E33 || cp == 0x0EB3)
return SPACINGMARK;
// hangul jamo
if (cp >= 0x1100 && cp <= 0x11FF) {
if (cp <= 0x115F)
return L;
if (cp <= 0x11A7)
return V;
return T;
}
// hangul syllables
int sindex = cp - SYLLABLE_BASE;
if (sindex >= 0 && sindex < SCOUNT) {
if (sindex % TCOUNT == 0)
return LV;
return LVT;
}
// hangul jamo_extended A
if (cp >= 0xA960 && cp <= 0xA97C)
return L;
// hangul jamo_extended B
if (cp >= 0xD7B0 && cp <= 0xD7C6)
return V;
if (cp >= 0xD7CB && cp <= 0xD7FB)
return T;
}
return OTHER;
}
}