Package mondrian.olap.type

Interface Type

All Known Implementing Classes:
BooleanType, CubeType, DateTimeType, DecimalType, DimensionType, EmptyType, HierarchyType, LevelType, MemberType, NullType, NumericType, ScalarType, SetType, StringType, SymbolType, TupleType
public interface Type
Type of an MDX expression.
Since:
Feb 17, 2005
Author:
jhyde

  • Method Summary

    Modifier and Type
    Method
    Description
    Type
    computeCommonType(Type type, int[] conversionCount)
    Returns a Type which is more general than this and the given Type.
    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.
    boolean
    isInstance(Object value)
    Returns whether a value is valid for a type.
    boolean
    usesDimension(Dimension dimension, boolean definitely)
    Returns whether this type contains a given dimension.
    boolean
    usesHierarchy(Hierarchy hierarchy, boolean definitely)
    Returns whether this type contains a given hierarchy.

  • Method Details

    • usesDimension

      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. 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.

      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

      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. 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].

      Parameters:
      hierarchy - Hierarchy
      definitely - If true, returns true only if this type definitely uses the hierarchy
      Returns:
      whether this Type uses the given Hierarchy

    • getDimension

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

    • getHierarchy

      Hierarchy getHierarchy()
      Returns the Hierarchy of this Type, or null if not known. If not applicable, throws.
      Returns:
      the Hierarchy of this type, or null if not known

    • getLevel

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

    • computeCommonType

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

    • isInstance

      boolean isInstance(Object value)
      Returns whether a value is valid for a type.
      Parameters:
      value - Value
      Returns:
      Whether value is valid for this type

    • getArity

      int getArity()
      Returns the number of fields in a tuple type, or a set of tuples. For most other types, in particular member type, returns 1.
      Returns:
      Arity of type