modules/regex/src/main/java/java/util/regex/SupplCharSet.java

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package java.util.regex;

/**
 * Represents node accepting single supplementary codepoint.
 */
class SupplCharSet extends LeafSet {

    /*
     * UTF-16 encoding of this supplementary codepoint
     */
    private char high = 0;

    private char low = 0;

    //int value of this supplementary codepoint
    private int ch;

    public SupplCharSet(int ch) {
        charCount = 2;
        this.ch = ch;
        char [] chUTF16 = Character.toChars(ch);
        high = chUTF16[0];
        
        /*
         * we suppose that SupplCharSet is
         * build over supplementary codepoints only
         */
        low = chUTF16[1];
    }
    
    public int accepts(int strIndex, CharSequence testString) {
        char high = testString.charAt(strIndex++);
        char low = testString.charAt(strIndex);
        return ((this.high == high) && (this.low == low)) ? 2 : -1;
    }
    
    public int find(int strIndex, CharSequence testString,
            MatchResultImpl matchResult) {
        
        if (testString instanceof String) {
            String testStr = (String) testString;
            int strLength = matchResult.getRightBound();

            while (strIndex < strLength) {
                strIndex = testStr.indexOf(high, strIndex);
                if (strIndex < 0)
                    return -1;
                
                strIndex++;
                if (strIndex < strLength) {
                    char ch = testStr.charAt(strIndex);
                    
                    if ((low == ch)
                            && (next.matches(strIndex + 1,
                                    testString, matchResult) >= 0)) {
                        return --strIndex;
                    }
                    strIndex++;                    
                }
            }
            return -1;
        }
        
        return super.find(strIndex, testString, matchResult); 
    }

    public int findBack(int strIndex, int lastIndex, CharSequence testString,
            MatchResultImpl matchResult) {
        
        if (testString instanceof String) {
            String testStr = (String) testString;
            
            while (lastIndex >= strIndex) {
                lastIndex = testStr.lastIndexOf(low, lastIndex);
                lastIndex--;
                if (lastIndex < 0 || lastIndex < strIndex) {
                    return -1;
                }
                
                if ((high == testStr.charAt(lastIndex)) 
                        && next.matches(lastIndex + 2,
                                testString, matchResult) >= 0) {
                    return lastIndex;
                }

                lastIndex--;
            }
            return -1;
        }
        
        return super.findBack(strIndex, lastIndex, testString, matchResult); 
    }

    protected String getName() {
        return "" + high + low;
    }
    
    protected int getCodePoint() {
        return ch;
    }
    
    public boolean first(AbstractSet set) {
        if (set instanceof SupplCharSet) {
            return ((SupplCharSet) set).getCodePoint() == ch;
        } else if (set instanceof SupplRangeSet) {
            return ((SupplRangeSet) set)
                    .contains(ch);
        } else if (set instanceof CharSet) {
            return false;
        } else if (set instanceof RangeSet) {
            return false;
        }

        return true;
    }
}