org.basex.query.expr
Class And

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.expr.Expr
          org.basex.query.expr.Arr
              org.basex.query.expr.And

public final class And
extends Arr

And expression.

Author:

Workgroup DBIS, University of Konstanz 2005-09, ISC License, Christian Gruen

Field Summary

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

expr

Constructor Summary

And(Expr[] e)
Constructor.

Method Summary

Bln	atomic(QueryContext ctx) Evaluates the expression and returns the resulting item or a null reference.
Expr	comp(QueryContext ctx) Optimizes and compiles the expression.
void	indexAccessible(QueryContext ctx, IndexContext ic) Checks if an index can be used for query evaluation.
Expr	indexEquivalent(QueryContext ctx, IndexContext ic) Returns an equivalent expression which accesses an index structure.
Return	returned(QueryContext ctx) Indicates the return type of an expression.
java.lang.String	toString()

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

duplicates, plan, removable, remove, uses

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

addText, checkCtx, checkDbl, checkItr, e, ebv, i, iter, sameAs, size, test

Methods inherited from class org.basex.query.ExprInfo

color, info, name

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

And

public And(Expr[] e)

Constructor.

Parameters:

e - expression list

Method Detail

comp

public Expr comp(QueryContext ctx)
          throws QueryException

Description copied from class: Expr

Optimizes and compiles the expression.

Overrides:

comp in class Arr

Parameters:

ctx - query context

Returns:

optimized Expression

Throws:

QueryException - evaluation exception

atomic

public Bln atomic(QueryContext ctx)
           throws QueryException

Description copied from class: Expr

Evaluates the expression and returns the resulting item or a null reference. If this method is not overwritten, Expr.iter(org.basex.query.QueryContext) must be implemented.

Overrides:

atomic in class Expr

Parameters:

ctx - query context

Returns:

iterator

Throws:

QueryException - query exception

returned

public Return returned(QueryContext ctx)

Description copied from class: Expr

Indicates the return type of an expression. Called by the compiler to check if expressions can be reformulated. null is returned by default.

Overrides:

returned in class Expr

Parameters:

ctx - query context

Returns:

result of check

indexAccessible

public void indexAccessible(QueryContext ctx,
                            IndexContext ic)
                     throws QueryException

Description copied from class: Expr

Checks if an index can be used for query evaluation.

Overrides:

indexAccessible in class Expr

Parameters:

ctx - query context

ic - index context

Throws:

QueryException - Exception

indexEquivalent

public Expr indexEquivalent(QueryContext ctx,
                            IndexContext ic)
                     throws QueryException

Description copied from class: Expr

Returns an equivalent expression which accesses an index structure. Must be called if Expr.indexAccessible(org.basex.query.QueryContext, org.basex.query.IndexContext) is implemented for an expression.

Overrides:

indexEquivalent in class Arr

Parameters:

ctx - query context

ic - index context

Returns:

Equivalent index-expression or null

Throws:

QueryException - Exception

toString

public java.lang.String toString()

Specified by:

toString in class ExprInfo