Package morfologik.fsa

Class FSATraversal

java.lang.Object

morfologik.fsa.FSATraversal

public final class FSATraversal
extends java.lang.Object

This class implements some common matching and scanning operations on a generic FSA.

Field Summary

Fields

Modifier and Type	Field	Description
private FSA	fsa	Target automaton.

Constructor Summary

Constructors

Constructor	Description
FSATraversal(FSA fsa)	Traversals of the given FSA.

Method Summary

Modifier and Type	Method	Description
MatchResult	match(byte[] sequence)
MatchResult	match(byte[] sequence, int node)
MatchResult	match(byte[] sequence, int start, int length, int node)	Finds a matching path in the dictionary for a given sequence of labels from sequence and starting at node node.
MatchResult	match(MatchResult reuse, byte[] sequence, int start, int length, int node)	Same as match(byte[], int, int, int), but allows passing a reusable MatchResult object so that no intermediate garbage is produced.
int	perfectHash(byte[] sequence)
int	perfectHash(byte[] sequence, int start, int length, int node)	Calculate perfect hash for a given input sequence of bytes.

Methods inherited from class java.lang.Object

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

Field Detail

fsa

private final FSA fsa

Target automaton.

Constructor Detail

FSATraversal

public FSATraversal(FSA fsa)

Traversals of the given FSA.

Parameters:

fsa - The target automaton for traversals.

Method Detail

perfectHash

public int perfectHash(byte[] sequence,
                       int start,
                       int length,
                       int node)

Calculate perfect hash for a given input sequence of bytes. The perfect hash requires that FSA is built with FSAFlags.NUMBERS and corresponds to the sequential order of input sequences used at automaton construction time.

Parameters:

sequence - The byte sequence to calculate perfect hash for.

start - Start index in the sequence array.

length - Length of the byte sequence, must be at least 1.

node - The node to start traversal from, typically the root node.

Returns:

Returns a unique integer assigned to the input sequence in the automaton (reflecting the number of that sequence in the input used to build the automaton). Returns a negative integer if the input sequence was not part of the input from which the automaton was created. The type of mismatch is a constant defined in MatchResult.

perfectHash

public int perfectHash(byte[] sequence)

Parameters:

sequence - The byte sequence to calculate perfect hash for.

Returns:

Returns a unique integer assigned to the input sequence in the automaton (reflecting the number of that sequence in the input used to build the automaton). Returns a negative integer if the input sequence was not part of the input from which the automaton was created. The type of mismatch is a constant defined in MatchResult.

See Also:

perfectHash(byte[], int, int, int)

match

public MatchResult match(MatchResult reuse,
                         byte[] sequence,
                         int start,
                         int length,
                         int node)

Same as match(byte[], int, int, int), but allows passing a reusable MatchResult object so that no intermediate garbage is produced.

Parameters:

reuse - The MatchResult to reuse.

sequence - Input sequence to look for in the automaton.

start - Start index in the sequence array.

length - Length of the byte sequence, must be at least 1.

node - The node to start traversal from, typically the root node.

Returns:

The same object as reuse, but with updated match MatchResult.kind and other relevant fields.

match

public MatchResult match(byte[] sequence,
                         int start,
                         int length,
                         int node)

Finds a matching path in the dictionary for a given sequence of labels from sequence and starting at node node.

Parameters:

sequence - Input sequence to look for in the automaton.

start - Start index in the sequence array.

length - Length of the byte sequence, must be at least 1.

node - The node to start traversal from, typically the root node.

Returns:

MatchResult with updated match MatchResult.kind.

See Also:

match(byte [], int)

match

public MatchResult match(byte[] sequence,
                         int node)

Parameters:

sequence - Input sequence to look for in the automaton.

node - The node to start traversal from, typically the root node.

Returns:

MatchResult with updated match MatchResult.kind.

See Also:

match(byte [], int)

match

public MatchResult match(byte[] sequence)

Parameters:

sequence - Input sequence to look for in the automaton.

Returns:

MatchResult with updated match MatchResult.kind.

See Also:

match(byte [], int)