org.eclipse.equinox.internal.p2.metadata.expression

Class ContextExpression<T>

java.lang.Object

org.eclipse.equinox.internal.p2.metadata.expression.Expression

org.eclipse.equinox.internal.p2.metadata.expression.Unary

org.eclipse.equinox.internal.p2.metadata.expression.ContextExpression<T>

All Implemented Interfaces:

java.lang.Comparable<Expression>, IExpressionConstants, IContextExpression<T>, IExpression

public class ContextExpression<T>
extends Unary
implements IContextExpression<T>

The context expression is the top expression in context queries. It introduces the variable 'everything' and initialized it with the iterator that represents all available items.

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.equinox.internal.p2.metadata.expression.Expression

Expression.VariableFinder

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.Object[]	parameters

Fields inherited from class org.eclipse.equinox.internal.p2.metadata.expression.Unary

operand

Fields inherited from interface org.eclipse.equinox.p2.metadata.expression.IExpression

TYPE_ALL, TYPE_AND, TYPE_ARRAY, TYPE_ASSIGNMENT, TYPE_AT, TYPE_COLLECT, TYPE_CONDITION, TYPE_EQUALS, TYPE_EXISTS, TYPE_FIRST, TYPE_FLATTEN, TYPE_FUNCTION, TYPE_GREATER, TYPE_GREATER_EQUAL, TYPE_INTERSECT, TYPE_LAMBDA, TYPE_LATEST, TYPE_LESS, TYPE_LESS_EQUAL, TYPE_LIMIT, TYPE_LITERAL, TYPE_MATCHES, TYPE_MEMBER, TYPE_NOT, TYPE_NOT_EQUALS, TYPE_OR, TYPE_PARAMETER, TYPE_PIPE, TYPE_SELECT, TYPE_TRAVERSE, TYPE_UNION, TYPE_UNIQUE, TYPE_VARIABLE

Fields inherited from interface org.eclipse.equinox.internal.p2.metadata.expression.IExpressionConstants

KEYWORD_ALL, KEYWORD_BOOLEAN, KEYWORD_CLASS, KEYWORD_COLLECT, KEYWORD_EXISTS, KEYWORD_FALSE, KEYWORD_FILTER, KEYWORD_FIRST, KEYWORD_FLATTEN, KEYWORD_INTERSECT, KEYWORD_IQUERY, KEYWORD_LATEST, KEYWORD_LIMIT, KEYWORD_LOCALIZED_KEYS, KEYWORD_LOCALIZED_MAP, KEYWORD_LOCALIZED_PROPERTY, KEYWORD_NULL, KEYWORD_RANGE, KEYWORD_SATISFIES_ALL, KEYWORD_SATISFIES_ANY, KEYWORD_SELECT, KEYWORD_SET, KEYWORD_TRAVERSE, KEYWORD_TRUE, KEYWORD_UNION, KEYWORD_UNIQUE, KEYWORD_VERSION, OPERATOR_AND, OPERATOR_ARRAY, OPERATOR_ASSIGN, OPERATOR_AT, OPERATOR_EACH, OPERATOR_ELSE, OPERATOR_EQUALS, OPERATOR_GT, OPERATOR_GT_EQUAL, OPERATOR_IF, OPERATOR_LT, OPERATOR_LT_EQUAL, OPERATOR_MATCHES, OPERATOR_MEMBER, OPERATOR_NOT, OPERATOR_NOT_EQUALS, OPERATOR_OR, OPERATOR_PARAMETER, PRIORITY_AND, PRIORITY_ASSIGNMENT, PRIORITY_BINARY, PRIORITY_COLLECTION, PRIORITY_COMMA, PRIORITY_CONDITION, PRIORITY_FUNCTION, PRIORITY_LAMBDA, PRIORITY_LITERAL, PRIORITY_MAX, PRIORITY_MEMBER, PRIORITY_NOT, PRIORITY_OR, PRIORITY_VARIABLE, VARIABLE_EVERYTHING, VARIABLE_THIS

Constructor Summary

Constructors

Constructor and Description
ContextExpression(Expression expression, java.lang.Object[] parameters)

Method Summary

Modifier and Type	Method and Description
boolean	accept(IExpressionVisitor visitor) Let the visitor visit this instance and all expressions that this instance contains.
IEvaluationContext	createContext(java.lang.Class<? extends T> elementClass, IIndexProvider<T> indexProvider) Creates a new context to be passed to a subsequent evaluation.
IEvaluationContext	createContext(java.lang.Class<? extends T> elementClass, java.util.Iterator<T> iterator) Creates a new context to be passed to a subsequent evaluation.
java.lang.Object	evaluate(IEvaluationContext context) Evaluate this expression with given context and variables.
int	getExpressionType() Returns the expression type (see TYPE_xxx constants).
java.lang.String	getOperator()
java.lang.Object[]	getParameters() Returns the parameters that this context expression was created with.
int	getPriority()
int	hashCode()
java.util.Iterator<T>	iterator(IEvaluationContext context) Evaluate the expression and return the expected collection result as an iterator
void	toString(java.lang.StringBuffer bld) Appends the string representation of this expression to the collector collector.
void	toString(java.lang.StringBuffer bld, Variable rootVariable)

Methods inherited from class org.eclipse.equinox.internal.p2.metadata.expression.Unary

compareTo, equals, getOperand

Methods inherited from class org.eclipse.equinox.internal.p2.metadata.expression.Expression

appendOperand, assertLength, assertLength, compare, elementsToString, equals, evaluateAsIterator, getIndexCandidateMembers, hashCode, isReferenceTo, needsTranslationSupport, toLDAPString, toLDAPString, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.equinox.p2.metadata.expression.IExpression

toLDAPString

Field Detail

parameters

protected final java.lang.Object[] parameters

Constructor Detail

ContextExpression

public ContextExpression(Expression expression,
                         java.lang.Object[] parameters)

Method Detail

accept

public boolean accept(IExpressionVisitor visitor)

Description copied from class: Expression

Let the visitor visit this instance and all expressions that this instance contains.

Specified by:

accept in interface IExpression

Overrides:

accept in class Unary

Parameters:

visitor - The visiting visitor.

Returns:

true if the visitor should continue visiting, false otherwise.

toString

public void toString(java.lang.StringBuffer bld,
                     Variable rootVariable)

Overrides:

toString in class Unary

createContext

public IEvaluationContext createContext(java.lang.Class<? extends T> elementClass,
                                        IIndexProvider<T> indexProvider)

Description copied from interface: IContextExpression

Creates a new context to be passed to a subsequent evaluation. The context will have the variable 'everything' set to an expression that represents the everything iterator filtered for instances of elementClass.

The values of the iterator will be copied if necessary (when everything is referenced more then once).

Specified by:

createContext in interface IContextExpression<T>

Parameters:

elementClass - the class of the iterator elements

indexProvider - The index provider that represents all queried material.

Returns:

A new evaluation context.

createContext

public IEvaluationContext createContext(java.lang.Class<? extends T> elementClass,
                                        java.util.Iterator<T> iterator)

Description copied from interface: IContextExpression

Creates a new context to be passed to a subsequent evaluation. The context will have the variable 'everything' set to an expression that represents the everything iterator filtered for instances of elementClass.

The values of the iterator will be copied if necessary (when everything is referenced more then once).

Specified by:

createContext in interface IContextExpression<T>

Parameters:

elementClass - the class of the iterator elements

iterator - The iterator that represents all queried material.

Returns:

A new evaluation context.

evaluate

public java.lang.Object evaluate(IEvaluationContext context)

Description copied from class: Expression

Evaluate this expression with given context and variables.

Specified by:

evaluate in interface IExpression

Overrides:

evaluate in class Unary

Parameters:

context - The evaluation context

Returns:

The result of the evaluation.

getExpressionType

public int getExpressionType()

Description copied from interface: IExpression

Returns the expression type (see TYPE_xxx constants).

Specified by:

getExpressionType in interface IExpression

getOperator

public java.lang.String getOperator()

Specified by:

getOperator in class Expression

getPriority

public int getPriority()

Specified by:

getPriority in class Expression

getParameters

public java.lang.Object[] getParameters()

Description copied from interface: IContextExpression

Returns the parameters that this context expression was created with.

Specified by:

getParameters in interface IContextExpression<T>

Returns:

An array of parameters, possibly empty but never null.

hashCode

public int hashCode()

Overrides:

hashCode in class Unary

iterator

public java.util.Iterator<T> iterator(IEvaluationContext context)

Description copied from interface: IContextExpression

Evaluate the expression and return the expected collection result as an iterator

Specified by:

iterator in interface IContextExpression<T>

Parameters:

context - The evaluation context

Returns:

The result of the evaluation.

toString

public void toString(java.lang.StringBuffer bld)

Description copied from interface: IExpression

Appends the string representation of this expression to the collector collector.

Specified by:

toString in interface IExpression

Overrides:

toString in class Expression