mondrian.olap.type

Class ScalarType

java.lang.Object

mondrian.olap.type.ScalarType

All Implemented Interfaces:

Type

Direct Known Subclasses:

BooleanType, DateTimeType, EmptyType, NullType, NumericType, StringType, SymbolType

public class ScalarType
extends Object
implements Type

Base class for types which represent scalar values.

An instance of this class means a scalar value of unknown type. Usually one of the derived classes NumericType, StringType, BooleanType is used instead.

Since:

Feb 17, 2005

Author:

jhyde

Constructor Summary

Constructors

Modifier	Constructor and Description
	ScalarType() Creates a ScalarType.
protected	ScalarType(String digest) Creates a ScalarType (or subtype) with a given digest.

Method Summary

Modifier and Type	Method and Description
Type	computeCommonType(Type type, int[] conversionCount) Returns a Type which is more general than this and the given Type.
boolean	equals(Object obj)
int	getArity() Returns the number of fields in a tuple type, or a set of tuples.
Dimension	getDimension() Returns the Dimension of this Type, or null if not known.
Hierarchy	getHierarchy() Returns the Hierarchy of this Type, or null if not known.
Level	getLevel() Returns the Level of this Type, or null if not known.
int	hashCode()
boolean	isInstance(Object value) Returns whether a value is valid for a type.
String	toString()
boolean	usesDimension(Dimension dimension, boolean definitely) Returns whether this type contains a given dimension. For example: DimensionType([Gender]) uses only the [Gender] dimension. TupleType(MemberType([Gender]), MemberType([Store])) uses [Gender] and [Store] dimensions. The definitely parameter comes into play when the dimensional information is incomplete.
boolean	usesHierarchy(Hierarchy hierarchy, boolean definitely) Returns whether this type contains a given hierarchy. For example: HierarchyType([Customer].[Gender]) uses only the [Customer].[Gender] hierarchy. TupleType(MemberType([Customer].[Gender]), MemberType([Store].[Store])) uses [Gender] and [Store] dimensions. The definitely parameter comes into play when the dimensional information is incomplete.

Methods inherited from class java.lang.Object

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

Constructor Detail

ScalarType

public ScalarType()

Creates a ScalarType.

ScalarType

protected ScalarType(String digest)

Creates a ScalarType (or subtype) with a given digest.

The digest is used for toString() and hashCode().

Parameters:

digest - Description of this type

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

usesDimension

public boolean usesDimension(Dimension dimension,
                             boolean definitely)

Description copied from interface: Type

Returns whether this type contains a given dimension.

For example:

• DimensionType([Gender]) uses only the [Gender] dimension.
• TupleType(MemberType([Gender]), MemberType([Store])) uses [Gender] and [Store] dimensions.

The definitely parameter comes into play when the dimensional information is incomplete. For example, when applied to TupleType(MemberType(null), MemberType([Store])), usesDimension([Gender], false) returns true because it is possible that the expression returns a member of the [Gender] dimension; but usesDimension([Gender], true) returns true because it is possible that the expression returns a member of the [Gender] dimension.

Specified by:

usesDimension in interface Type

Parameters:

dimension - Dimension

definitely - If true, returns true only if this type definitely uses the dimension

Returns:

whether this Type uses the given Dimension

usesHierarchy

public boolean usesHierarchy(Hierarchy hierarchy,
                             boolean definitely)

Description copied from interface: Type

Returns whether this type contains a given hierarchy.

For example:

• HierarchyType([Customer].[Gender]) uses only the [Customer].[Gender] hierarchy.
• TupleType(MemberType([Customer].[Gender]), MemberType([Store].[Store])) uses [Gender] and [Store] dimensions.

The definitely parameter comes into play when the dimensional information is incomplete. For example, when applied to TupleType(MemberType([Customer]), MemberType([Store])), usesDimension([Customer].[Gender], false) returns true because the expression returns a member of one hierarchy of the [Customer] dimension and that might be a member of the [Customer].[Gender] hierarchy; but usesDimension([Customer].[Gender], true) returns false because might return a member of a different hierarchy, such as [Customer].[State].

Specified by:

usesHierarchy in interface Type

Parameters:

hierarchy - Hierarchy

definitely - If true, returns true only if this type definitely uses the hierarchy

Returns:

whether this Type uses the given Hierarchy

getHierarchy

public Hierarchy getHierarchy()

Description copied from interface: Type

Returns the Hierarchy of this Type, or null if not known. If not applicable, throws.

Specified by:

getHierarchy in interface Type

Returns:

the Hierarchy of this type, or null if not known

getLevel

public Level getLevel()

Description copied from interface: Type

Returns the Level of this Type, or null if not known. If not applicable, throws.

Specified by:

getLevel in interface Type

Returns:

the Level of this Type

computeCommonType

public Type computeCommonType(Type type,
                              int[] conversionCount)

Description copied from interface: Type

Returns a Type which is more general than this and the given Type. The type returned is broad enough to hold any value of either type, but no broader. If there is no such type, returns null.

Some examples:

• The common type for StringType and NumericType is ScalarType.
• The common type for NumericType and DecimalType(4, 2) is NumericType.
• DimensionType and NumericType have no common type.

If conversionCount is not null, implicit conversions such as HierarchyType to DimensionType are considered; the parameter is incremented by the number of conversions performed.

Some examples:

• The common type for HierarchyType(hierarchy=Time.Weekly) and LevelType(dimension=Time), if conversions are allowed, is HierarchyType(dimension=Time).

One use of common types is to determine the types of the arguments to the Iif function. For example, the call

Iif(1 > 2, [Measures].[Unit Sales], 5)

has type ScalarType, because DecimalType(-1, 0) is a subtype of ScalarType, and MeasureType can be converted implicitly to ScalarType.

Specified by:

computeCommonType in interface Type

Parameters:

type - Type

conversionCount - Number of conversions; output parameter that is incremented each time a conversion is performed; if null, conversions are not considered

Returns:

More general type

getDimension

public Dimension getDimension()

Description copied from interface: Type

Returns the Dimension of this Type, or null if not known. If not applicable, throws.

Specified by:

getDimension in interface Type

Returns:

the Dimension of this Type, or null if not known.

isInstance

public boolean isInstance(Object value)

Description copied from interface: Type

Returns whether a value is valid for a type.

Specified by:

isInstance in interface Type

Parameters:

value - Value

Returns:

Whether value is valid for this type

getArity

public int getArity()

Description copied from interface: Type

Returns the number of fields in a tuple type, or a set of tuples. For most other types, in particular member type, returns 1.

Specified by:

getArity in interface Type

Returns:

Arity of type