be.SIRAPRISE.typeimplementations

Class GROUP

java.lang.Object

be.SIRAPRISE.typeimplementations.RelationalOperator

be.SIRAPRISE.typeimplementations.GROUP

All Implemented Interfaces:

OperatorGenerator

@OperatorGeneratorCharacteristics(maximumArgumentCount=2,
                                  minimumArgumentCount=2,
                                  name="GROUP",
                                  signature={EXPRESSION,STRING})
 @MonoRelationOperator
public abstract class GROUP
extends RelationalOperator

Author:

erwin

Constructor Summary

Constructors

Constructor and Description
GROUP()

Method Summary

Modifier and Type	Method and Description
static RelationBuffer	computeGroup(RelationBuffer relationBuffer, java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes, java.util.Set<NameIdentifier> retainedAttributeNames)
static Relation	computeGroup(Relation relation, java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes)
static java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>>	getGroupSpec(java.lang.String groupSpecText) Gets The group spec in the form of a mapping from NameIdentifiers to sets of them
OperatorImplementation_V0105	getOperatorImplementation(OperatorGeneratorArgument[] args) Gets an implementation instance of the operator.
static GROUPInvocationResultDetails	validateExpressionDetails(Heading heading, java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes, java.lang.String predicate, java.util.Collection<? extends KeyDef> inputKeySpecifications)

Methods inherited from class be.SIRAPRISE.typeimplementations.RelationalOperator

getInvocationName, getMaximumArgumentCount, getMinimumArgumentCount, getName, getOperatorGeneratorSignature, isMonoRelationOperator, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

GROUP

public GROUP()

Method Detail

computeGroup

public static Relation computeGroup(Relation relation,
                                    java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes)
                             throws EvaluationException

Parameters:

relation - the relation to be subjected to grouping

groupAttributes - The specification of the groupings to be applied. Each entry consists of an attribute name for the relation-valued attribute in the result, and the set of attributes of this relation that that relation-typed attribute is to include.

Returns:

the given relation, grouped together according to the specs provided in groupAttributes

Throws:

EvaluationException - If the evaluation fails for any reason

computeGroup

public static RelationBuffer computeGroup(RelationBuffer relationBuffer,
                                          java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes,
                                          java.util.Set<NameIdentifier> retainedAttributeNames)

Parameters:

relationBuffer - the relation to be subjected to grouping

groupAttributes - The specification of the groupings to be applied. Each entry consists of an attribute name for the relation-valued attribute in the result, and the set of attributes of this relation that that relation-typed attribute is to include.

retainedAttributeNames - The set of attributes to retain from the input expression, which is also the set of attributes to group by

Returns:

the given relation, grouped together according to the specs provided in groupAttributes

getGroupSpec

public static java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> getGroupSpec(java.lang.String groupSpecText)
                                                                                throws DuplicateNameException,
                                                                                       NoClosingBracketException,
                                                                                       InvalidEscapedCharacterException,
                                                                                       MissingEscapedCharacterException,
                                                                                       NoValueCorrespondingToNameException

Gets The group spec in the form of a mapping from NameIdentifiers to sets of them

Parameters:

groupSpecText - A sequence of g(l) specs where g is an attribute name and l is a comma-separated list of attribute names. Note that surrounding parentheses must have been removed.

Returns:

The group spec in the form of a mapping from NameIdentifiers to sets of them

Throws:

DuplicateNameException - If the String argument contains a duplicate name.

NoClosingBracketException - If an opening bracket was found with an unmatched closing bracket

InvalidEscapedCharacterException - If the string argument contains an invalid escape sequence, i.e. a backslash followed by a character other than ()\

MissingEscapedCharacterException - If the string argument ends with the escape token (backslash), with the subsequent escaped character missing

NoValueCorrespondingToNameException - If the string does not hold any opening bracket, meaning a name with no corresponding value is contained.

validateExpressionDetails

public static GROUPInvocationResultDetails validateExpressionDetails(Heading heading,
                                                                     java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes,
                                                                     java.lang.String predicate,
                                                                     java.util.Collection<? extends KeyDef> inputKeySpecifications)
                                                              throws NonExistingAttributeException,
                                                                     GroupAttributeOverlapException,
                                                                     AttributeGroupedTwiceException

Parameters:

heading - The heading of the relation that is subjected to grouping

groupAttributes - The specification of the groupings to be applied. Each entry consists of an attribute name for the relation-valued attribute in the result, and the set of attributes of this relation that that relation-typed attribute is to include.

predicate - The predicate of which the input relation is the extension

inputKeySpecifications - The key specifications known to be satisfied by the input relation

Returns:

The heading of the result from applying grouping as specified to the given relation type

Throws:

NonExistingAttributeException - If an attribute is specified for inclusion in an RVA that does not exist in the input

GroupAttributeOverlapException - If an attribute name is used for specifying an output RVA that also appears in the heading of the input. Note that

AttributeGroupedTwiceException - If an attribute is specified for inclusion in more than one RVA

getOperatorImplementation

public final OperatorImplementation_V0105 getOperatorImplementation(OperatorGeneratorArgument[] args)
                                                             throws NotFoundException

Description copied from interface: OperatorGenerator

Gets an implementation instance of the operator.

Parameters:

args - The arguments from which the instance is to be created. There must be exactly as many arguments as there are elements in the list returned from OperatorGenerator.getOperatorGeneratorSignature(). The correspondence between OperatorGeneratorArgumentType values and OperatorGeneratorArgument types is given in the table below :

correspondence between OperatorGeneratorArgumentType values and OperatorGeneratorArgument types

OperatorGeneratorArgumentType value	OperatorGeneratorArgument type
EXPRESSION	NonScalarOperatorGeneratorExpressionArgument
EXPRESSIONWITHSCOPE	NonScalarOperatorGeneratorExpressionArgument
STRING	NonScalarOperatorGeneratorTextArgument

Returns:

an instance of the operator

Throws:

NotFoundException - If the given OperatorGeneratorArguments do not satisfy all of the rules of the OperatorGenerator. These rules are specific to each OperatorGenerator.