Package org.basex.query.expr

Class Intersect

java.lang.Object

org.basex.query.expr.ExprInfo

org.basex.query.expr.Expr

org.basex.query.expr.ParseExpr

org.basex.query.expr.Arr

org.basex.query.expr.Intersect

public final class Intersect
extends Arr

Intersect expression.

Author:

BaseX Team 2005-22, BSD License, Christian Gruen

Field Summary

Fields inherited from class org.basex.query.expr.Arr

exprs

Fields inherited from class org.basex.query.expr.ParseExpr

exprType, info

Constructor Summary

Constructors

Constructor	Description
Intersect(InputInfo info, Expr[] exprs)	Constructor.

Method Summary

Modifier and Type	Method	Description
Expr	copy(CompileContext cc, IntObjMap<Var> vm)	Copies an expression.
boolean	ddo()	Indicates if this expression returns items in document order without duplicates.
boolean	equals(Object obj)	This function is e.g.
Iter	iter(QueryContext qc)	Evaluates the expression and returns an iterator on the resulting items.
Expr	optimize(CompileContext cc)	Optimizes an already compiled expression without recompiling its sub-expressions.
void	toString(QueryString qs)	Creates a query string.
void	toXml(QueryPlan plan)	Creates a query plan.
Value	value(QueryContext qc)	Evaluates the expression and returns the resulting value.

Methods inherited from class org.basex.query.expr.Arr

accept, allAreValues, args, checkUp, compile, copyAll, count, exprSize, flatten, has, inline, inlineable, mayBePositional, removeEmpty, simplifyAll

Methods inherited from class org.basex.query.expr.ParseExpr

adoptType, atomValue, checkAllUp, checkNoEmpty, checkNoEmpty, checkNoneUp, checkNoUp, checkType, checkType, checkUp, copyType, ctxValue, data, ebv, info, item, refineType, seqType, size, test, toArray, toArray, toAtomItem, toB64, toB64, toBin, toBin, toBoolean, toBoolean, toBytes, toBytes, toDouble, toDouble, toElem, toFloat, toFunction, toItem, toItem, toLong, toLong, toMap, toMap, toNode, toNode, toNodeOrNull, toNumber, toNumberOrNull, toQNm, toQNm, toString, toString, toStringOrNull, toToken, toToken, toTokenOrNull, toZeroToken

Methods inherited from class org.basex.query.expr.Expr

arg, atomItem, atomIter, funcType, hasFreeVars, indexAccessible, isSimple, markTailCalls, mergeEbv, optimizePos, simplify, simplifyFor, typeCheck, uses, vacuous, visitAll

Methods inherited from class org.basex.query.expr.ExprInfo

description, toErrorString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

Intersect

public Intersect(InputInfo info,
                 Expr[] exprs)

Constructor.

Parameters:

info - input info

exprs - expressions

Method Detail

copy

public Expr copy(CompileContext cc,
                 IntObjMap<Var> vm)

Description copied from class: Expr

Copies an expression. Used for inlining functions, or for copying static queries. It is utilized by VarRef.inline(org.basex.query.InlineContext), FuncItem.inline(org.basex.query.expr.Expr[], org.basex.query.CompileContext), Closure.inline(org.basex.query.InlineContext) and StaticFunc.inline(org.basex.query.expr.Expr[], org.basex.query.CompileContext).

Specified by:

copy in class Expr

Parameters:

cc - compilation context

vm - mapping from old variable IDs to new variable copies. Required by Closure.copy(org.basex.query.CompileContext, org.basex.util.hash.IntObjMap<org.basex.query.var.Var>) and VarRef.copy(org.basex.query.CompileContext, org.basex.util.hash.IntObjMap<org.basex.query.var.Var>)

Returns:

copied expression

equals

public boolean equals(Object obj)

Description copied from class: Arr

This function is e.g. called by:

• If.optimize(CompileContext), Switch.optimize(CompileContext), Typeswitch.optimize(CompileContext), in order to discard identical expressions.
• CmpR.mergeEbv(Expr, boolean, CompileContext) or CmpSR.mergeEbv(Expr, boolean, CompileContext), in order to merge expressions with identical input.
• CmpG.optimize(CompileContext) or CmpV.optimize(CompileContext), in order to pre-evaluate equality tests.
• CmpG.optimize(CompileContext), in order to compare the start and end value.
• PathCache, in order to find identical root values at runtime.

Must be overwritten by implementing class.

Overrides:

equals in class Arr

optimize

public final Expr optimize(CompileContext cc)
                    throws QueryException

Description copied from class: Expr

Optimizes an already compiled expression without recompiling its sub-expressions.

Overrides:

optimize in class Expr

Parameters:

cc - compilation context

Returns:

optimized expression

Throws:

QueryException - query exception

iter

public final Iter iter(QueryContext qc)
                throws QueryException

Description copied from class: Expr

Evaluates the expression and returns an iterator on the resulting items. The implementation of this method is optional.

Overrides:

iter in class ParseExpr

Parameters:

qc - query context

Returns:

iterator

Throws:

QueryException - query exception

value

public final Value value(QueryContext qc)
                  throws QueryException

Description copied from class: Expr

Evaluates the expression and returns the resulting value. If this method is not implemented, Expr.item(QueryContext, InputInfo) must be implemented instead.

Overrides:

value in class ParseExpr

Parameters:

qc - query context

Returns:

value

Throws:

QueryException - query exception

ddo

public final boolean ddo()

Description copied from class: Expr

Indicates if this expression returns items in document order without duplicates.

Overrides:

ddo in class Expr

Returns:

result of check

toXml

public final void toXml(QueryPlan plan)

Description copied from class: ExprInfo

Creates a query plan.

Overrides:

toXml in class Arr

Parameters:

plan - expression plan

toString

public final void toString(QueryString qs)

Description copied from class: ExprInfo

Creates a query string.

Specified by:

toString in class ExprInfo

Parameters:

qs - query string builder