Don't know if this has been asked/reported before, but is the example code
for hangul composition in UAX 15 correct?
The code is:
public static String composeHangul(String source) {
int len = source.length();
if (len == 0) return "";
StringBuffer result = new StringBuffer();
char last = source.charAt(0); // copy first char
result.append(last);
for (int i = 1; i < len; ++i) {
char ch = source.charAt(i);
// 1. check to see if two current characters are L and V
int LIndex = last - LBase;
if (0 <= LIndex && LIndex < LCount) {
int VIndex = ch - VBase;
if (0 <= VIndex && VIndex < VCount) {
// make syllable of form LV
last = (char)(SBase + (LIndex * VCount + VIndex) * TCount);
result.setCharAt(result.length()-1, last); // reset last
continue; // discard ch
}
}
// 2. check to see if two current characters are LV and T
int SIndex = last - SBase;
if (0 <= SIndex && SIndex < SCount && (SIndex % TCount) == 0) {
int TIndex = ch - TBase;
if (0 <= TIndex && TIndex <= TCount) {
// make syllable of form LVT
last += TIndex;
result.setCharAt(result.length()-1, last); // reset last
continue; // discard ch
}
}
// if neither case was true, just add the character
last = ch;
result.append(ch);
}
return result.toString();
}
Suppose I feed it 0xAC00 0x11C3. 0xAC00 is an LV.
This will do step 2:
SIndex = 0xAC00 - 0xAC00 = 0
TIndex = 0x11C3 - 0x11A7 = 28
Which causes the "(0 <= TIndex && TIndex <= TCount)" to be true.
And the resulting output is 0xAC00 + 28 = 0xAC1C which is not
an LVT but an LV syllable!
The TIndex <= TCount should be TIndex < TCount I think. IMO the
example would be more clear if the Hangul_Syllable_Type property
would be used.
A somewhat related question. I know next to nothing about Hangul
[de]composition so forgive me for asking silly questions. In the
UnicodeData.txt file there are much more than the 19 L, 21 V, and
28 L jamos. Are the other jamos not use to compose syllables, or
does the syllable block represent an incomplete set of compatibility
characters? What's is it?
Theo
