com.yahoo.bullet.query.expressions

Class FieldExpression

java.lang.Object

com.yahoo.bullet.query.expressions.Expression

com.yahoo.bullet.query.expressions.FieldExpression

All Implemented Interfaces:

Serializable

public class FieldExpression
extends Expression

An expression that requires a field name. An index or key can be provided for lists and maps as well as a subkey for lists of maps and maps of maps.

See Also:

Serialized Form

Field Summary

Fields inherited from class com.yahoo.bullet.query.expressions.Expression

type

Constructor Summary

Constructors

Constructor and Description
FieldExpression(String field) Constructor that creates a field expression.
FieldExpression(String field, Integer index) Constructor that creates a field expression with a list index.
FieldExpression(String field, Integer index, String subKey) Constructor that creates a field expression with a list index and a map subkey.
FieldExpression(String field, String key) Constructor that creates a field expression with a map key.
FieldExpression(String field, String key, String subKey) Constructor that creates a field expression with map key and a map subkey.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
Evaluator	getEvaluator() Gets a new instance of an evaluator for this expression.
String	getName() Gets the name of this field expression formatted with delimiters for any index and/or keys.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldExpression

public FieldExpression(String field)

Constructor that creates a field expression.

Parameters:

field - The non-null field to get.

FieldExpression

public FieldExpression(String field,
                       Integer index)

Constructor that creates a field expression with a list index.

Parameters:

field - The non-null field to get.

index - The non-null index to get from the field.

FieldExpression

public FieldExpression(String field,
                       String key)

Constructor that creates a field expression with a map key.

Parameters:

field - The non-null field to get.

key - The non-null key to get from the field.

FieldExpression

public FieldExpression(String field,
                       Integer index,
                       String subKey)

Constructor that creates a field expression with a list index and a map subkey.

Parameters:

field - The non-null field to get.

index - The non-null index to get from the field.

subKey - The non-null subkey to get from the field[index].

FieldExpression

public FieldExpression(String field,
                       String key,
                       String subKey)

Constructor that creates a field expression with map key and a map subkey.

Parameters:

field - The non-null field to get.

key - The non-null key to get from the field.

subKey - The non-null subkey to get from the field.key.

Method Detail

getName

public String getName()

Gets the name of this field expression formatted with delimiters for any index and/or keys.

Returns:

The name of this field expression.

getEvaluator

public Evaluator getEvaluator()

Description copied from class: Expression

Gets a new instance of an evaluator for this expression.

Specified by:

getEvaluator in class Expression

Returns:

A newly-constructed evaluator for this expression.

equals

public boolean equals(Object obj)

Specified by:

equals in class Expression

hashCode

public int hashCode()

Specified by:

hashCode in class Expression

toString

public String toString()

Overrides:

toString in class Expression