org.eigenbase.util.mapping
Class Mappings.PartialMapping

java.lang.Object
  org.eigenbase.util.mapping.Mappings.AbstractMapping
      org.eigenbase.util.mapping.Mappings.FiniteAbstractMapping
          org.eigenbase.util.mapping.Mappings.PartialMapping

All Implemented Interfaces:

Iterable<IntPair>, Mapping, Mappings.FunctionMapping, Mappings.SourceMapping, Mappings.TargetMapping

Direct Known Subclasses:

Mappings.SurjectionWithInverse

Enclosing class:

Mappings

public static class Mappings.PartialMapping
extends Mappings.FiniteAbstractMapping
implements Mapping, Mappings.FunctionMapping, Mappings.TargetMapping

A mapping where a source at most one target, and every target has at most one source.

Nested Class Summary

private class

Mappings.PartialMapping.MappingItr

Field Summary

private MappingType	mappingType
protected int[]	sources
protected int[]	targets

Constructor Summary

private	Mappings.PartialMapping(int[] sources, int[] targets, MappingType mappingType)
	Mappings.PartialMapping(int sourceCount, int targetCount, MappingType mappingType) Creates a partial mapping.
	Mappings.PartialMapping(List<Integer> sourceList, int sourceCount, MappingType mappingType) Creates a partial mapping from a list.

Method Summary

private static void	assertPartialValid(int[] sources, int[] targets)
MappingType	getMappingType()
int	getSourceCount() Returns the number of sources.
int	getSourceOpt(int target)
int	getTarget(int source) Returns the target that a source maps to.
int	getTargetCount() Returns the number of targets.
int	getTargetOpt(int source) Returns the target that a source maps to, or -1 if it is not mapped.
Mapping	inverse()
boolean	isIdentity() Returns whether this mapping is the identity.
protected boolean	isValid()
Iterator<IntPair>	iterator() Returns an iterator over the elements in this mapping.
void	set(int source, int target)

Methods inherited from class org.eigenbase.util.mapping.Mappings.FiniteAbstractMapping

equals, hashCode, toString

Methods inherited from class org.eigenbase.util.mapping.Mappings.AbstractMapping

getSource

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.eigenbase.util.mapping.Mappings.SourceMapping

getSource

Field Detail

sources

protected final int[] sources

targets

protected final int[] targets

mappingType

private final MappingType mappingType

Constructor Detail

Mappings.PartialMapping

public Mappings.PartialMapping(int sourceCount,
                               int targetCount,
                               MappingType mappingType)

Creates a partial mapping.

Initially, no element is mapped to any other:

source	0	1	2
target	-1	-1	-1

target	0	1	2	3
source	-1	-1	-1	-1

Parameters:

sourceCount - Number of source elements

targetCount - Number of target elements

mappingType - Mapping type; must not allow multiple sources per target or multiple targets per source

Mappings.PartialMapping

public Mappings.PartialMapping(List<Integer> sourceList,
                               int sourceCount,
                               MappingType mappingType)

Creates a partial mapping from a list. For example, PartialMapping({1, 2, 4}, 6) creates the mapping

source	0	1	2	3	4	5
target	-1	0	1	-1	2	-1

Parameters:

sourceList - List whose i'th element is the source of target #i

sourceCount - Number of elements in the source domain

mappingType - Mapping type, must be MappingType.PartialSurjection or stronger.

Mappings.PartialMapping

private Mappings.PartialMapping(int[] sources,
                                int[] targets,
                                MappingType mappingType)

Method Detail

getMappingType

public MappingType getMappingType()

Specified by:

getMappingType in interface Mapping

Specified by:

getMappingType in interface Mappings.FunctionMapping

Specified by:

getMappingType in interface Mappings.SourceMapping

Specified by:

getMappingType in interface Mappings.TargetMapping

getSourceCount

public int getSourceCount()

Description copied from interface: Mapping

Returns the number of sources. Valid sources will be in the range 0 .. sourceCount.

Specified by:

getSourceCount in interface Mapping

Specified by:

getSourceCount in interface Mappings.FunctionMapping

Specified by:

getSourceCount in interface Mappings.SourceMapping

Specified by:

getSourceCount in interface Mappings.TargetMapping

Overrides:

getSourceCount in class Mappings.AbstractMapping

getTargetCount

public int getTargetCount()

Description copied from interface: Mapping

Returns the number of targets. Valid targets will be in the range 0 .. targetCount.

Specified by:

getTargetCount in interface Mapping

Specified by:

getTargetCount in interface Mappings.SourceMapping

Specified by:

getTargetCount in interface Mappings.TargetMapping

Overrides:

getTargetCount in class Mappings.AbstractMapping

inverse

public Mapping inverse()

Specified by:

inverse in interface Mappings.SourceMapping

Specified by:

inverse in interface Mappings.TargetMapping

iterator

public Iterator<IntPair> iterator()

Description copied from interface: Mapping

Returns an iterator over the elements in this mapping.

This method is optional; implementations may throw UnsupportedOperationException.

Specified by:

iterator in interface Iterable<IntPair>

Specified by:

iterator in interface Mapping

Overrides:

iterator in class Mappings.FiniteAbstractMapping

isValid

protected boolean isValid()

assertPartialValid

private static void assertPartialValid(int[] sources,
                                       int[] targets)

set

public void set(int source,
                int target)

Specified by:

set in interface Mappings.TargetMapping

Overrides:

set in class Mappings.AbstractMapping

getSourceOpt

public int getSourceOpt(int target)

Specified by:

getSourceOpt in interface Mappings.SourceMapping

Specified by:

getSourceOpt in interface Mappings.TargetMapping

Overrides:

getSourceOpt in class Mappings.AbstractMapping

getTargetOpt

public int getTargetOpt(int source)

Description copied from interface: Mappings.FunctionMapping

Returns the target that a source maps to, or -1 if it is not mapped.

Specified by:

getTargetOpt in interface Mappings.FunctionMapping

Specified by:

getTargetOpt in interface Mappings.SourceMapping

Specified by:

getTargetOpt in interface Mappings.TargetMapping

Overrides:

getTargetOpt in class Mappings.AbstractMapping

getTarget

public int getTarget(int source)

Description copied from interface: Mappings.FunctionMapping

Returns the target that a source maps to.

Specified by:

getTarget in interface Mappings.FunctionMapping

Specified by:

getTarget in interface Mappings.TargetMapping

Overrides:

getTarget in class Mappings.AbstractMapping

Parameters:

source - source

Returns:

target

isIdentity

public boolean isIdentity()

Description copied from interface: Mapping

Returns whether this mapping is the identity.

Specified by:

isIdentity in interface Mapping

Specified by:

isIdentity in interface Mappings.SourceMapping

Overrides:

isIdentity in class Mappings.AbstractMapping