com.oracle.truffle.regex.tregex.matchers

Class HybridBitSetMatcher

java.lang.Object

com.oracle.truffle.regex.tregex.matchers.CharMatcher

com.oracle.truffle.regex.tregex.matchers.InvertibleCharMatcher

com.oracle.truffle.regex.tregex.matchers.HybridBitSetMatcher

public final class HybridBitSetMatcher
extends InvertibleCharMatcher

Character matcher that compiles to a binary search in a sorted list of ranges, like RangeTreeMatcher, but replaces some subtrees with bit-set matches. Specifically, if the character set contains many short ranges that differ only in the lowest byte, those ranges are converted to a bit-set, which is checked when the binary search finds that the given character is in the byte range denoted by the bit set. The threshold for bit-set conversion is defined by TRegexOptions.TRegexRangeToBitSetConversionThreshold. Example:

 Character set:
 [0x02, 0x04, 0x06, 0x1000, 0x1020-0x1030]

 Resulting Hybrid matcher with threshold = 3:
 - ranges:   [0x02-0x06,          0x1000, 0x1020-0x1030]
 - bit-sets: [[0x02, 0x04, 0x06], null,   null         ]
 

See Also:

CompressedCodePointSet

Method Summary

Modifier and Type	Method and Description
static HybridBitSetMatcher	create(boolean invert, CompressedCodePointSet ccps)
int	estimatedCost() Conservatively estimate the equivalent number of integer comparisons of calling CharMatcher.match(int).
boolean	match(int c) Check if a given code point matches this CharMatcher.
String	toString()

Methods inherited from class com.oracle.truffle.regex.tregex.matchers.InvertibleCharMatcher

modifiersToString, result, result

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

create

public static HybridBitSetMatcher create(boolean invert,
                                         CompressedCodePointSet ccps)

match

public boolean match(int c)

Description copied from class: CharMatcher

Check if a given code point matches this CharMatcher.

Specified by:

match in class CharMatcher

Parameters:

c - any code point.

Returns:

true if the character matches.

See Also:

CompilerDirectives.isPartialEvaluationConstant(Object)

estimatedCost

public int estimatedCost()

Description copied from class: CharMatcher

Conservatively estimate the equivalent number of integer comparisons of calling CharMatcher.match(int).

Specified by:

estimatedCost in class CharMatcher

Returns:

the number of integer comparisons one call to CharMatcher.match(int) is roughly equivalent to. Array loads are treated as two comparisons.

toString

public String toString()

Overrides:

toString in class Object