de.caff.generics.algorithm

Class FastCharSequenceSearch

java.lang.Object

de.caff.generics.algorithm.FastCharSequenceSearch

public class FastCharSequenceSearch
extends java.lang.Object

Fast search algorithm in sequences of random-accessible char values.

Currently only forward search is implemented, but basically both the search indexable and the searched indexable can be reversed before searching.

Although based on integers this may also be used for searches in byte or character sequences.

It also allows for case-insensitive search in character indexables, as this is simple and fast to implement.

Since:

July 07, 2020

Author:

Rammi

Constructor Summary

Constructors

Constructor and Description
FastCharSequenceSearch(boolean caseInsensitive, char... searchTerm) Convenience constructor.
FastCharSequenceSearch(char... searchTerm) Convenience constructor.
FastCharSequenceSearch(CharIndexable searchTerm) Constructor.
FastCharSequenceSearch(CharIndexable searchTerm, boolean caseInsensitive) Constructor.
FastCharSequenceSearch(java.lang.String searchTerm) Convenience constructor.
FastCharSequenceSearch(java.lang.String searchTerm, boolean caseInsensitive) Convenience constructor.

Method Summary

Modifier and Type	Method and Description
IntIndexable	findAllMatches(CharIndexable data, boolean allowOverlaps) Find all matches.
int	findFirst(CharIndexable data) Find the first appearance of the search term in the given data.
int	findNext(CharIndexable data, int pos) Find the next appearance of the search term after the given position in the given data.
int	findNext(CharIndexable data, int pos, int end) Find the next appearance of the search term after the given start position and before the given end position in the given data.
CharIndexable	getSearchTerm() Get the search term.
boolean	isCaseInsensitive() Is this search done case-insensitive?

Methods inherited from class java.lang.Object

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

Constructor Detail

FastCharSequenceSearch

public FastCharSequenceSearch(@NotNull
                              CharIndexable searchTerm)

Constructor.

Parameters:

searchTerm - term to search for

FastCharSequenceSearch

public FastCharSequenceSearch(@NotNull
                              CharIndexable searchTerm,
                              boolean caseInsensitive)

Constructor.

Parameters:

searchTerm - term to search for

caseInsensitive - true: searching is done in a case-insensitive way (assuming UTF-16 encoding for all character values)
false: characters have to match exactly

FastCharSequenceSearch

public FastCharSequenceSearch(@NotNull
                              java.lang.String searchTerm)

Convenience constructor.

Parameters:

searchTerm - search term

FastCharSequenceSearch

public FastCharSequenceSearch(@NotNull
                              java.lang.String searchTerm,
                              boolean caseInsensitive)

Convenience constructor.

Parameters:

searchTerm - search term

caseInsensitive - true: searching is done in a case-insensitive way (assuming UTF-16 encoding for all character values)
false: characters have to match exactly

FastCharSequenceSearch

public FastCharSequenceSearch(@NotNull
                              char... searchTerm)

Convenience constructor.

Parameters:

searchTerm - search term

FastCharSequenceSearch

public FastCharSequenceSearch(boolean caseInsensitive,
                              @NotNull
                              char... searchTerm)

Convenience constructor.

Parameters:

searchTerm - search term

caseInsensitive - true: searching is done in a case-insensitive way (assuming UTF-16 encoding for all character values)
false: characters have to match exactly

Method Detail

getSearchTerm

@NotNull
public CharIndexable getSearchTerm()

Get the search term.

Returns:

search term

isCaseInsensitive

public boolean isCaseInsensitive()

Is this search done case-insensitive?

Returns:

true: if case is not cared for
false: if characters have to match exactly

findFirst

public int findFirst(@NotNull
                     CharIndexable data)

Find the first appearance of the search term in the given data.

Parameters:

data - data to search through

Returns:

index of first appearance of the search term in the given data, or -1 if there was nothing found

findNext

public int findNext(@NotNull
                    CharIndexable data,
                    int pos)

Find the next appearance of the search term after the given position in the given data.

Parameters:

data - data to search through

pos - position to start the search

Returns:

position of next appearance of the search term in the given data after the given position, or -1 if there was nothing found between the position and the end of data

findNext

public int findNext(@NotNull
                    CharIndexable data,
                    int pos,
                    int end)

Find the next appearance of the search term after the given start position and before the given end position in the given data.

Parameters:

data - data to search through

pos - position to start the search

end - position to end the search, the whole search term has to fit before this position to be found

Returns:

position of next appearance of the search term in the given data after the given start position and before the given end position, or -1 if there was nothing found between the position and the end of data

findAllMatches

@NotNull
public IntIndexable findAllMatches(@NotNull
                                            CharIndexable data,
                                            boolean allowOverlaps)

Find all matches.

Parameters:

data - data to search

allowOverlaps - allow overlapping sequences in the matches?

Returns:

start position of all matches