com.espertech.esper.client.soda

Interface Expression

All Superinterfaces:

Serializable

All Known Implementing Classes:

AccessProjectionExpressionBase, ArithmaticExpression, ArrayExpression, AvedevProjectionExpression, AvgProjectionExpression, BetweenExpression, BitwiseOpExpression, CaseSwitchExpression, CaseWhenThenExpression, CastExpression, CoalesceExpression, CompareListExpression, ConcatExpression, Conjunction, ConstantExpression, CountEverProjectionExpression, CountProjectionExpression, CountStarProjectionExpression, CrontabFrequencyExpression, CrontabParameterExpression, CrontabParameterSetExpression, CrontabRangeExpression, CurrentEvaluationContextExpression, CurrentTimestampExpression, Disjunction, DotExpression, ExpressionBase, ExpressionPlaceholder, FirstEverProjectionExpression, FirstProjectionExpression, GroupingExpression, GroupingIdExpression, InExpression, InstanceOfExpression, IStreamBuiltinExpression, Junction, LambdaExpression, LastEverProjectionExpression, LastProjectionExpression, LikeExpression, MaxProjectionExpression, MaxRowExpression, MedianProjectionExpression, MinProjectionExpression, MinRowExpression, NamedParameterExpression, NewInstanceOperatorExpression, NewOperatorExpression, NotExpression, OrderedObjectParamExpression, PlugInProjectionExpression, PreviousExpression, PriorExpression, PropertyExistsExpression, PropertyValueExpression, RegExpExpression, RelationalOpExpression, SingleRowMethodExpression, StaticMethodExpression, StddevProjectionExpression, StreamWildcardExpression, SubqueryExistsExpression, SubqueryExpression, SubqueryInExpression, SubqueryQualifiedExpression, SubstitutionParameterExpressionBase, SubstitutionParameterExpressionIndexed, SubstitutionParameterExpressionNamed, SumProjectionExpression, TableAccessExpression, TimePeriodExpression, TypeOfExpression, WildcardExpression, WindowProjectionExpression

public interface Expression
extends Serializable

Interface representing an expression for use in select-clauses, where-clauses, having-clauses, order-by clauses and streams based on filters and pattern filter expressions.

Expressions are organized into a tree-like structure with nodes representing sub-expressions.

Certain types of nodes have certain requirements towards the number or types of nodes that are expected as sub-expressions to an expression.

Method Summary

Modifier and Type	Method and Description
List<Expression>	getChildren() Returns the list of sub-expressions (child expressions) to the current expression node.
ExpressionPrecedenceEnum	getPrecedence() Returns precedence.
String	getTreeObjectName() Returns the tree of object name, for use by tools to assign an identifier to an expression.
void	setChildren(List<Expression> children) Sets the list of sub-expressions (child expressions) to the current expression node.
void	setTreeObjectName(String objectName) Sets the tree of object name, for use by tools to assign an identifier to an expression.
void	toEPL(StringWriter writer, ExpressionPrecedenceEnum parentPrecedence) Write expression considering precedence.

Method Detail

getChildren

List<Expression> getChildren()

Returns the list of sub-expressions (child expressions) to the current expression node.

Returns:

child expressions or empty list if there are no child expressions

setChildren

void setChildren(List<Expression> children)

Sets the list of sub-expressions (child expressions) to the current expression node.

Parameters:

children - child expressions or empty list if there are no child expressions

getTreeObjectName

String getTreeObjectName()

Returns the tree of object name, for use by tools to assign an identifier to an expression.

Returns:

tree object id

setTreeObjectName

void setTreeObjectName(String objectName)

Sets the tree of object name, for use by tools to assign an identifier to an expression.

Parameters:

objectName - tree object id

getPrecedence

ExpressionPrecedenceEnum getPrecedence()

Returns precedence.

Returns:

precedence

toEPL

void toEPL(StringWriter writer,
           ExpressionPrecedenceEnum parentPrecedence)

Write expression considering precedence.

Parameters:

writer - to use

parentPrecedence - precedence