org.basex.query.expr
Class Range

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

public final class Range
extends Arr

Range 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

Range(Expr e1, Expr e2)
Constructor.

Method Summary

Expr	comp(QueryContext ctx) Optimizes and compiles the expression.
Iter	iter(QueryContext ctx) Evaluates the expression and returns an iterator on the resulting items.
long[]	range(QueryContext ctx) Returns the start and end value of the range operator, or null if the range could not be evaluated.
Return	returned(QueryContext ctx) Indicates the return type of an expression.
long	size(QueryContext ctx) Returns the sequence size or 1.
java.lang.String	toString()

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

duplicates, indexEquivalent, plan, removable, remove, uses

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

addText, atomic, checkCtx, checkDbl, checkItr, e, ebv, i, indexAccessible, sameAs, 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

Range

public Range(Expr e1,
             Expr e2)

Constructor.

Parameters:

e1 - first expression

e2 - second expression

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

iter

public Iter iter(QueryContext ctx)
          throws QueryException

Description copied from class: Expr

Evaluates the expression and returns an iterator on the resulting items. If this method is not overwritten, Expr.atomic(org.basex.query.QueryContext) must be implemented.

Overrides:

iter in class Expr

Parameters:

ctx - query context

Returns:

resulting item

Throws:

QueryException - evaluation exception

size

public long size(QueryContext ctx)
          throws QueryException

Description copied from class: Expr

Returns the sequence size or 1.

Overrides:

size in class Expr

Parameters:

ctx - query context

Returns:

result of check

Throws:

QueryException - Exception

range

public long[] range(QueryContext ctx)
             throws QueryException

Returns the start and end value of the range operator, or null if the range could not be evaluated.

Parameters:

ctx - query context

Returns:

value array

Throws:

QueryException - 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

toString

public java.lang.String toString()

Specified by:

toString in class ExprInfo