it.unimi.dsi.util
Interface StringMap<S extends CharSequence>

All Superinterfaces:

Function<CharSequence,Long>, Object2LongFunction<CharSequence>, Serializable

All Known Subinterfaces:

PrefixMap<S>

All Known Implementing Classes:

AbstractPrefixMap, ImmutableExternalPrefixMap, LiterallySignedStringMap, ShiftAddXorSignedStringMap, StringMaps.SynchronizedPrefixMap, StringMaps.SynchronizedStringMap, TernaryIntervalSearchTree

public interface StringMap<S extends CharSequence>
extends Object2LongFunction<CharSequence>, Serializable

A map from strings to numbers (and possibly vice versa).

String maps represent mappings from strings (actually, any subclass of CharSequence) to numbers; they can support reverse mapping, too. The latter has usually sense only if the map is minimal and perfect (e.g., a bijection of a set of string with an initial segment of the natural numbers of the same size). String maps are useful for terms of an MG4J inverted index, URLs of a WebGraph-compressed web snapshot, and so on.

Warning: the return value of list() is a fastutil ObjectList. This in principle is not sensible, as string maps return longs (they extend Object2LongFunction), and ObjectList has only integer index support. At some point in the future, this problem will be addressed with a full-blown hierarchy of long lists (and corresponding iterators) in fastutil.

Since:

0.2

Author:

Sebastiano Vigna

Method Summary

ObjectList<? extends S>

list() Returns a list view of the domain of this string map (optional operation).

Methods inherited from interface it.unimi.dsi.fastutil.objects.Object2LongFunction

defaultReturnValue, defaultReturnValue, getLong, put, removeLong

Methods inherited from interface it.unimi.dsi.fastutil.Function

clear, containsKey, get, put, remove, size

Method Detail

list

ObjectList<? extends S> list()

Returns a list view of the domain of this string map (optional operation).

Note that the list view acts as an inverse of the mapping implemented by this map.

Returns:

a list view of the domain of this string map, or null if this map does not support this operation.