org.apache.pig.impl.logicalLayer
Class UnaryExpressionOperator

java.lang.Object
  extended by org.apache.pig.impl.plan.Operator<LOVisitor>
      extended by org.apache.pig.impl.logicalLayer.LogicalOperator
          extended by org.apache.pig.impl.logicalLayer.ExpressionOperator
              extended by org.apache.pig.impl.logicalLayer.UnaryExpressionOperator
All Implemented Interfaces:
Serializable, Cloneable, Comparable<Operator>
Direct Known Subclasses:
LOIsNull, LONegative, LONot

public abstract class UnaryExpressionOperator
extends ExpressionOperator

This abstract class represents the logical Unary Expression Operator The unary operator has an operand and an operator. The format of the expression is operator operand. The operator is implicit and not recorded in the class

See Also:
Serialized Form

Field Summary
protected  ExpressionOperator mOperand
           
 
Fields inherited from class org.apache.pig.impl.logicalLayer.ExpressionOperator
mFieldSchema, mIsFieldSchemaComputed
 
Fields inherited from class org.apache.pig.impl.logicalLayer.LogicalOperator
mAlias, mIsSchemaComputed, mPlan, mRequestedParallelism, mSchema, mType
 
Fields inherited from class org.apache.pig.impl.plan.Operator
mKey
 
Constructor Summary
UnaryExpressionOperator(LogicalPlan plan, OperatorKey k, ExpressionOperator operand)
           
UnaryExpressionOperator(LogicalPlan plan, OperatorKey k, int rp, ExpressionOperator operand)
           
 
Method Summary
protected  Object clone()
           
 ExpressionOperator getOperand()
           
 void setOperand(ExpressionOperator eOp)
           
 boolean supportsMultipleInputs()
          Indicates whether this operator supports multiple inputs.
 void visit(LOVisitor v)
          Visit this node with the provided visitor.
 
Methods inherited from class org.apache.pig.impl.logicalLayer.ExpressionOperator
getFieldSchema, getSchema, getType, regenerateFieldSchema, setFieldSchema, supportsMultipleOutputs, unsetFieldSchema
 
Methods inherited from class org.apache.pig.impl.logicalLayer.LogicalOperator
forceSchema, getAlias, getOperatorKey, getPlan, getRequestedParallelism, reconcileSchema, regenerateSchema, setAlias, setCanonicalNames, setPlan, setRequestedParallelism, setSchema, setSchemaComputed, setType, toString, unsetSchema
 
Methods inherited from class org.apache.pig.impl.plan.Operator
compareTo, equals, hashCode, name
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

mOperand

protected ExpressionOperator mOperand
Constructor Detail

UnaryExpressionOperator

public UnaryExpressionOperator(LogicalPlan plan,
                               OperatorKey k,
                               int rp,
                               ExpressionOperator operand)
Parameters:
plan - Logical plan this operator is a part of.
k - Operator key to assign to this node.
rp - degree of requested parallelism with which to execute this node.
operand - ExpressionOperator the left hand side operand

UnaryExpressionOperator

public UnaryExpressionOperator(LogicalPlan plan,
                               OperatorKey k,
                               ExpressionOperator operand)
Parameters:
plan - Logical plan this operator is a part of.
k - Operator key to assign to this node.
operand - ExpressionOperator the left hand side operand
Method Detail

getOperand

public ExpressionOperator getOperand()

setOperand

public void setOperand(ExpressionOperator eOp)

visit

public void visit(LOVisitor v)
           throws VisitorException
Description copied from class: LogicalOperator
Visit this node with the provided visitor. This should only be called by the visitor class itself, never directly.

Specified by:
visit in class LogicalOperator
Parameters:
v - Visitor to visit with.
Throws:
VisitorException - if the visitor has a problem.

supportsMultipleInputs

public boolean supportsMultipleInputs()
Description copied from class: Operator
Indicates whether this operator supports multiple inputs.

Specified by:
supportsMultipleInputs in class Operator<LOVisitor>
Returns:
true if it does, otherwise false.

clone

protected Object clone()
                throws CloneNotSupportedException
Overrides:
clone in class ExpressionOperator
Throws:
CloneNotSupportedException
See Also:
Do not use the clone method directly. Operators are cloned when logical plans are cloned using {@link LogicalPlanCloner}


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