Function<java.lang.CharSequence,java.lang.Long>
, Object2LongFunction<java.lang.CharSequence>
, StringMap<MutableString>
, java.io.Serializable
, java.util.function.Function<java.lang.CharSequence,java.lang.Long>
, java.util.function.ToLongFunction<java.lang.CharSequence>
public class LiterallySignedStringMap extends AbstractObject2LongFunction<java.lang.CharSequence> implements StringMap<MutableString>, java.io.Serializable
A minimal perfect hash function maps a set of string to an initial segment of the natural
numbers, but will actually map any string to that segment. We can check that
a string is part of the key set by hashing it to a value h, and checking that the h-th
string of the original list does coincide. Since, moreover, this class implements StringMap
,
and thus exposes the original list, we have a two-way
dictionary. In other words, this is a full StringMap
implementation.
Note that some care must be exercised: CharSequence
's contract does not
prescribe equality by content, so if your function behaves badly on some implementations of
CharSequence
you might make the checks fail. To avoid difficulties, the
constructor checks that every string in the list is hashed correctly.
For the same reason, this class implements StringMap<MutableString>
, and
requires that the list of strings provided at construction time is actually a list of
mutable strings.
A typical usage of this class pairs a FrontCodedStringList
with some kind
of succinct structure from Sux4J.
Modifier and Type | Field | Description |
---|---|---|
protected Object2LongFunction<? extends java.lang.CharSequence> |
function |
The underlying map.
|
protected ObjectList<? extends MutableString> |
list |
The underlying list.
|
protected int |
size |
The size of
list . |
defRetValue
Constructor | Description |
---|---|
LiterallySignedStringMap(Object2LongFunction<? extends java.lang.CharSequence> function,
ObjectList<? extends MutableString> list) |
Creates a new shift-add-xor signed string map using a given hash map.
|
Modifier and Type | Method | Description |
---|---|---|
boolean |
containsKey(java.lang.Object o) |
|
java.lang.Long |
get(java.lang.Object o) |
Deprecated.
|
long |
getLong(java.lang.Object o) |
|
ObjectList<? extends MutableString> |
list() |
Returns a list view of the domain of this string map (optional operation).
|
static void |
main(java.lang.String[] arg) |
|
int |
size() |
defaultReturnValue, defaultReturnValue
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
applyAsLong, defaultReturnValue, defaultReturnValue, put, put, remove, removeLong
protected final Object2LongFunction<? extends java.lang.CharSequence> function
protected final ObjectList<? extends MutableString> list
protected final int size
list
.public LiterallySignedStringMap(Object2LongFunction<? extends java.lang.CharSequence> function, ObjectList<? extends MutableString> list)
function
- a function mapping each string in list
to its ordinal position.list
- a list of strings.public long getLong(java.lang.Object o)
getLong
in interface Object2LongFunction<java.lang.CharSequence>
@Deprecated public java.lang.Long get(java.lang.Object o)
get
in interface Function<java.lang.CharSequence,java.lang.Long>
get
in interface Object2LongFunction<java.lang.CharSequence>
public int size()
public boolean containsKey(java.lang.Object o)
containsKey
in interface Function<java.lang.CharSequence,java.lang.Long>
public ObjectList<? extends MutableString> list()
StringMap
Note that the list view acts as an inverse of the mapping implemented by this map.
list
in interface StringMap<MutableString>
null
if this map does
not support this operation.public static void main(java.lang.String[] arg) throws java.io.IOException, JSAPException, java.lang.ClassNotFoundException, java.lang.SecurityException, java.lang.NoSuchMethodException
java.io.IOException
JSAPException
java.lang.ClassNotFoundException
java.lang.SecurityException
java.lang.NoSuchMethodException