Package org.apache.calcite.util.mapping

Interface Mapping

All Superinterfaces:

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

All Known Implementing Classes:

AbstractSourceMapping, AbstractTargetMapping, Mappings.AbstractMapping, Mappings.FiniteAbstractMapping, Mappings.IdentityMapping, Mappings.OverridingSourceMapping, Mappings.OverridingTargetMapping, Mappings.PartialMapping, Permutation

public interface Mapping
extends Mappings.FunctionMapping, Mappings.SourceMapping, Mappings.TargetMapping, Iterable<IntPair>

A Mapping is a relationship between a source domain to target domain of integers.

This interface represents the most general possible mapping. Depending on the MappingType of a particular mapping, some of the operations may not be applicable. If you call the method, you will receive a runtime error. For instance:

• If a target has more than one source, then the method Mappings.SourceMapping.getSource(int) will throw Mappings.TooManyElementsException.
• If a source has no targets, then the method Mappings.FunctionMapping.getTarget(int) will throw Mappings.NoElementException.

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all elements in the mapping.
MappingType	getMappingType()	Returns the mapping type.
int	getSourceCount()	Returns the number of sources.
int	getTargetCount()	Returns the number of targets.
boolean	isIdentity()	Returns whether this mapping is the identity.
Iterator<IntPair>	iterator()	Returns an iterator over the elements in this mapping.
int	size()	Returns the number of elements in the mapping.

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface org.apache.calcite.util.mapping.Mappings.SourceMapping

getSource, getSourceOpt, getTargetOpt, inverse

Methods inherited from interface org.apache.calcite.util.mapping.Mappings.TargetMapping

getSourceOpt, getTarget, getTargetOpt, inverse, set

Method Details

iterator

Iterator<IntPair> iterator()

Returns an iterator over the elements in this mapping.

This method is optional; implementations may throw UnsupportedOperationException.

Specified by:

iterator in interface Iterable<IntPair>

getSourceCount

int getSourceCount()

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

Specified by:

getSourceCount in interface Mappings.FunctionMapping

Specified by:

getSourceCount in interface Mappings.SourceMapping

Specified by:

getSourceCount in interface Mappings.TargetMapping

getTargetCount

int getTargetCount()

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

Specified by:

getTargetCount in interface Mappings.SourceMapping

Specified by:

getTargetCount in interface Mappings.TargetMapping

getMappingType

MappingType getMappingType()

Description copied from interface: Mappings.CoreMapping

Returns the mapping type.

Specified by:

getMappingType in interface Mappings.CoreMapping

Specified by:

getMappingType in interface Mappings.FunctionMapping

Specified by:

getMappingType in interface Mappings.SourceMapping

Returns:

Mapping type

isIdentity

boolean isIdentity()

Returns whether this mapping is the identity.

Specified by:

isIdentity in interface Mappings.SourceMapping

clear

void clear()

Removes all elements in the mapping.

size

int size()

Returns the number of elements in the mapping.

Specified by:

size in interface Mappings.CoreMapping