com.pervasive.datarush.functions

Class MapFunctions

java.lang.Object

com.pervasive.datarush.functions.MapFunctions

public class MapFunctions
extends Object

Provides implementations of common Map functions. These functions can be combined to construct more complex expressions.

These functions accept map objects as input parameters.

Constructor Summary

Constructors

Constructor and Description
MapFunctions()

Method Summary

Modifier and Type	Method and Description
static ScalarValuedFunction	containsKey(Map<Object,Object> leftValue, ScalarValuedFunction rightExpr) Builds an expression to check if a constant contains a mapping for the key specified by an expression.
static ScalarValuedFunction	containsKey(Map<Object,Object> leftValue, String rightField) Builds an expression to check if a constant contains a mapping for the key specified by the other field.
static ScalarValuedFunction	containsKey(ScalarValuedFunction leftExpr, ScalarValuedFunction rightExpr) Builds an expression to check if an expression contains a mapping for the key specified by the other expression.
static ScalarValuedFunction	containsKey(ScalarValuedFunction leftExpr, String rightField) Builds an expression to check if an expression contains a mapping for the key specified by the other field.
static ScalarValuedFunction	containsKey(String leftField, ScalarValuedFunction rightExpr) Builds an expression to check if a field contains a mapping for the key specified by an expression.
static ScalarValuedFunction	containsKey(String leftField, String rightField) Builds an expression to check if a field contains a mapping for the key specified by the other field.
static ScalarValuedFunction	mapGet(Map<Object,Object> leftValue, ScalarValuedFunction rightExpr) Builds an expression to get the value mapped to a key from specified constant.
static ScalarValuedFunction	mapGet(Map<Object,Object> leftValue, String rightField) Builds an expression to get the value mapped to a key from specified constant.
static ScalarValuedFunction	mapGet(ScalarValuedFunction leftExpr, ScalarValuedFunction rightExpr) Builds an expression to get the value mapped to a key from specified ScalarValuedFunction.
static ScalarValuedFunction	mapGet(ScalarValuedFunction leftExpr, String rightField) Builds an expression to get the value mapped to a key from specified ScalarValuedFunction.
static ScalarValuedFunction	mapGet(String leftField, ScalarValuedFunction rightExpr) Builds an expression to get the value mapped to a key from specified field.
static ScalarValuedFunction	mapGet(String leftField, String rightField) Builds an expression to get the value mapped to a key from specified field.
static ScalarValuedFunction	mapSize(ScalarValuedFunction expr) Builds an expression to get the number of kay-value mappings in ScalarValuedFunction expression.
static ScalarValuedFunction	mapSize(String field) Builds an expression to get the number of kay-value mappings in the specified field.
static ScalarValuedFunction	mapToString(ScalarValuedFunction expr) Builds an expression to get the string representation of a ScalarValuedFunction.
static ScalarValuedFunction	mapToString(String field) Builds an expression to get the string representation of a specified field.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MapFunctions

public MapFunctions()

Method Detail

mapGet

public static ScalarValuedFunction mapGet(String leftField,
                                          String rightField)

Builds an expression to get the value mapped to a key from specified field. The specified field must be of type Object and String respectively. The result will be of type Object. If the field value is null, the result is null.

Parameters:

leftField - the record field value on the left side of mapGet

rightField - the record field value on the right side of mapGet

Returns:

a function evaluating the expression

mapGet

public static ScalarValuedFunction mapGet(String leftField,
                                          ScalarValuedFunction rightExpr)

Builds an expression to get the value mapped to a key from specified field. The specified field must be of type Object and String respectively. The result will be of type Object. If the field value is null, the result is null.

Parameters:

leftField - the record field value on the left side of mapGet

rightExpr - the ScalarValuedFunction expression on the right side of mapGet

Returns:

a function evaluating the expression

mapGet

public static ScalarValuedFunction mapGet(Map<Object,Object> leftValue,
                                          String rightField)

Builds an expression to get the value mapped to a key from specified constant. The specified field must be of type Object and String respectively. The result will be of type Object. If the constant value is null, the result is null.

Parameters:

leftValue - the constant value on the left side of mapGet

rightField - the record field value on the right side of mapGet

Returns:

a function evaluating the expression

mapGet

public static ScalarValuedFunction mapGet(Map<Object,Object> leftValue,
                                          ScalarValuedFunction rightExpr)

Builds an expression to get the value mapped to a key from specified constant. The specified field must be of type Object and String respectively. The result will be of type Object. If the constant value is null, the result is null.

Parameters:

leftValue - the constant value on the left side of mapGet

rightExpr - the ScalarValuedFunction expression on the right side of mapGet

Returns:

a function evaluating the expression

mapGet

public static ScalarValuedFunction mapGet(ScalarValuedFunction leftExpr,
                                          String rightField)

Builds an expression to get the value mapped to a key from specified ScalarValuedFunction. The specified field must be of type Object and String respectively. The result will be of type Object. If an expression evaluates to null, the result is null.

Parameters:

leftExpr - the ScalarValuedFunction expression on the left side of mapGet

rightField - the record field value on the right side of mapGet

Returns:

a function evaluating the expression

mapGet

public static ScalarValuedFunction mapGet(ScalarValuedFunction leftExpr,
                                          ScalarValuedFunction rightExpr)

Builds an expression to get the value mapped to a key from specified ScalarValuedFunction. The specified field must be of type Object and String respectively. The result will be of type Object. If an expression evaluates to null, the result is null.

Parameters:

leftExpr - the ScalarValuedFunction expression on the left side of mapGet

rightExpr - the ScalarValuedFunction expression on the right side of mapGet

Returns:

a function evaluating the expression

mapSize

public static ScalarValuedFunction mapSize(String field)

Builds an expression to get the number of kay-value mappings in the specified field. The specified field must be of type Object The result will be of type integer. If the field value is null, the result is null.

Parameters:

field - the record field value

Returns:

a function evaluating the expression

mapSize

public static ScalarValuedFunction mapSize(ScalarValuedFunction expr)

Builds an expression to get the number of kay-value mappings in ScalarValuedFunction expression. The specified constant must be of type Object The result will be of type integer. If an expression evaluates to null, the result is null.

Parameters:

expr - the ScalarValuedFunction expression

Returns:

a function evaluating the expression

mapToString

public static ScalarValuedFunction mapToString(String field)

Builds an expression to get the string representation of a specified field. The specified field must be of type Object The result will be of type String. If the field value is null, the result is null.

Parameters:

field - the record field value

Returns:

a function evaluating the expression

mapToString

public static ScalarValuedFunction mapToString(ScalarValuedFunction expr)

Builds an expression to get the string representation of a ScalarValuedFunction. The specified expression must evaluate to Object The result will be of type String. If an expression evaluates to null, the result is null.

Parameters:

expr - the ScalarValuedFunction expression

Returns:

a function evaluating the expression

containsKey

public static ScalarValuedFunction containsKey(String leftField,
                                               String rightField)

Builds an expression to check if a field contains a mapping for the key specified by the other field. Operands must be of type Object and String. The result type is BOOLEAN. If the field representing a map is null, the result is null.

Parameters:

leftField - the record field value on the left side of containsKey

rightField - the record field value on the right side of containsKey

Returns:

a function evaluating the expression

containsKey

public static ScalarValuedFunction containsKey(String leftField,
                                               ScalarValuedFunction rightExpr)

Builds an expression to check if a field contains a mapping for the key specified by an expression. Operands must be of type Object and String. The result type is BOOLEAN. If the field representing a map is null, the result is null.

Parameters:

leftField - the record field value on the left side of containsKey

rightExpr - the ScalarValuedFunction expression on the right side of containsKey

Returns:

a function evaluating the expression

containsKey

public static ScalarValuedFunction containsKey(Map<Object,Object> leftValue,
                                               String rightField)

Builds an expression to check if a constant contains a mapping for the key specified by the other field. Operands must be of type Object and String. The result type is BOOLEAN. If the constant representing a map is null, the result is null.

Parameters:

leftValue - the constant value on the left side of containsKey

rightField - the record field value on the right side of containsKey

Returns:

a function evaluating the expression

containsKey

public static ScalarValuedFunction containsKey(Map<Object,Object> leftValue,
                                               ScalarValuedFunction rightExpr)

Builds an expression to check if a constant contains a mapping for the key specified by an expression. Operands must evaluate to Object and String. The result type is BOOLEAN. If the constant representing a map is null, the result is null.

Parameters:

leftValue - the constant value on the left side of containsKey

rightExpr - the ScalarValuedFunction expression on the right side of containsKey

Returns:

a function evaluating the expression

containsKey

public static ScalarValuedFunction containsKey(ScalarValuedFunction leftExpr,
                                               String rightField)

Builds an expression to check if an expression contains a mapping for the key specified by the other field. Operands must evaluate to Object and String. The result type is BOOLEAN. If an expression representing a map evaluates to null, the result is null.

Parameters:

leftExpr - the ScalarValuedFunction expression on the left side of containsKey

rightField - the record field value on the right side of containsKey

Returns:

a function evaluating the expression

containsKey

public static ScalarValuedFunction containsKey(ScalarValuedFunction leftExpr,
                                               ScalarValuedFunction rightExpr)

Builds an expression to check if an expression contains a mapping for the key specified by the other expression. Operands must evaluate to Object and String. The result type is BOOLEAN. If an expression representing a map evaluates to null, the result is null.

Parameters:

leftExpr - the ScalarValuedFunction expression on the left side of containsKey

rightExpr - the ScalarValuedFunction expression on the left side of containsKey

Returns:

a function evaluating the expression