org.basex.query.expr

Class And

java.lang.Object

org.basex.data.ExprInfo

org.basex.query.expr.Expr

org.basex.query.expr.ParseExpr

org.basex.query.expr.Arr

org.basex.query.expr.Logical

org.basex.query.expr.And

public final class And
extends Logical

And expression.

Author:

BaseX Team 2005-12, BSD License, Christian Gruen

Nested Class Summary

Nested classes/interfaces inherited from class org.basex.query.expr.Expr

Expr.Use

Field Summary

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

expr

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

input, size, type

Constructor Summary

Constructors

Constructor and Description
And(InputInfo ii, Expr[] e) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
Expr	comp(QueryContext ctx) Compiles and optimizes the expression, assigns data types and cardinalities.
boolean	indexAccessible(IndexContext ic) Checks if an expression can be rewritten to an index access.
Expr	indexEquivalent(IndexContext ic) Returns an equivalent expression which accesses an index structure.
Bln	item(QueryContext ctx, InputInfo ii) Evaluates the expression and returns the resulting item or a null reference, if the expression yields an empty sequence.
java.lang.String	toString()

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

allAreValues, count, plan, removable, remove, toString, uses

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

checkBln, checkColl, checkCreate, checkCtx, checkDbl, checkDBNode, checkEStr, checkEStr, checkIO, checkItem, checkItr, checkItr, checkMap, checkNode, checkNoEmpty, checkStr, checkType, checkUp, checkUp, checkWrite, compBln, ebv, iter, optPre, preEval, size, test, type, value

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

addText, compEbv, hasFreeVars, isEmpty, isFunction, isItem, isVacuous, isValue, iterable, markTailCalls, sameAs

Methods inherited from class org.basex.data.ExprInfo

description, info

Methods inherited from class java.lang.Object

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

Constructor Detail

And

public And(InputInfo ii,
   Expr[] e)

Constructor.

Parameters:

ii - input info

e - expression list

Method Detail

comp

public Expr comp(QueryContext ctx)
          throws QueryException

Description copied from class: Expr

Compiles and optimizes the expression, assigns data types and cardinalities.

Overrides:

comp in class Logical

Parameters:

ctx - query context

Returns:

optimized expression

Throws:

QueryException - query exception

item

public Bln item(QueryContext ctx,
       InputInfo ii)
         throws QueryException

Description copied from class: Expr

Evaluates the expression and returns the resulting item or a null reference, if the expression yields an empty sequence. If this method is not overwritten, Expr.iter(org.basex.query.QueryContext) must be implemented by an expression, as it may be called by this method.

Overrides:

item in class ParseExpr

Parameters:

ctx - query context

ii - input info

Returns:

iterator

Throws:

QueryException - query exception

indexAccessible

public boolean indexAccessible(IndexContext ic)
                        throws QueryException

Description copied from class: Expr

Checks if an expression can be rewritten to an index access. If this method is implemented, Expr.indexEquivalent(org.basex.query.util.IndexContext) must be implemented as well.

Overrides:

indexAccessible in class Expr

Parameters:

ic - index context

Returns:

true if an index can be used

Throws:

QueryException - query exception

indexEquivalent

public Expr indexEquivalent(IndexContext ic)
                     throws QueryException

Description copied from class: Expr

Returns an equivalent expression which accesses an index structure. Will be called if Expr.indexAccessible(org.basex.query.util.IndexContext) is returns true for an expression.

Overrides:

indexEquivalent in class Arr

Parameters:

ic - index context

Returns:

equivalent index-expression

Throws:

QueryException - query exception

toString

public java.lang.String toString()

Specified by:

toString in class ExprInfo