org.basex.query.expr
Class IndexAccess

java.lang.Object
  extended by org.basex.data.ExprInfo
      extended by org.basex.query.expr.Expr
          extended by org.basex.query.expr.ParseExpr
              extended by org.basex.query.expr.Simple
                  extended by org.basex.query.expr.IndexAccess
Direct Known Subclasses:
RangeAccess, StringRangeAccess, ValueAccess

public abstract class IndexAccess
extends Simple

This abstract class retrieves values from an index.

Author:
BaseX Team 2005-12, BSD License, Christian Gruen

Nested Class Summary
 
Nested classes/interfaces inherited from class org.basex.query.expr.Expr
Expr.Flag
 
Field Summary
 
Fields inherited from class org.basex.query.expr.ParseExpr
info, size, type
 
Constructor Summary
protected IndexAccess(IndexContext ic, InputInfo ii)
          Constructor.
 
Method Summary
abstract  NodeIter iter(QueryContext ctx)
          Evaluates the expression and returns an iterator on the resulting items.
 boolean iterable()
          Returns true if the expression is iterable, i.e., if it will not contain any duplicate nodes and if all nodes will be are sorted.
 
Methods inherited from class org.basex.query.expr.Simple
accept, checkUp, compile, count, exprSize, has, inline, plan, removable
 
Methods inherited from class org.basex.query.expr.ParseExpr
checkAdmin, checkAllUp, checkBinary, checkBln, checkColl, checkCreate, checkCtx, checkDbl, checkDBNode, checkEStr, checkEStr, checkFunc, checkItem, checkItr, checkItr, checkMap, checkNode, checkNode, checkNode, checkNoEmpty, checkNoneUp, checkNoUp, checkQNm, checkStr, checkStr, checkStrBin, checkType, checkWrite, compBln, copyType, ebv, item, optPre, preEval, size, test, type, value
 
Methods inherited from class org.basex.query.expr.Expr
addText, compEbv, copy, copy, hasFreeVars, indexAccessible, indexEquivalent, inlineAll, isEmpty, isFunction, isItem, isVacuous, isValue, markTailCalls, optimize, sameAs, uses, visitAll
 
Methods inherited from class org.basex.data.ExprInfo
addPlan, addPlan, description, info, planAttr, planElem, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

IndexAccess

protected IndexAccess(IndexContext ic,
                      InputInfo ii)
Constructor.

Parameters:
ic - index context
ii - input info
Method Detail

iter

public abstract NodeIter 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.item(org.basex.query.QueryContext, org.basex.util.InputInfo) must be implemented by an expression, as it may be called by this method.

Overrides:
iter in class ParseExpr
Parameters:
ctx - query context
Returns:
resulting item
Throws:
QueryException - query exception

iterable

public final boolean iterable()
Description copied from class: Expr
Returns true if the expression is iterable, i.e., if it will not contain any duplicate nodes and if all nodes will be are sorted. The return value of this method is only relevant for node sequences. It is e.g. called by AxisPath.

Overrides:
iterable in class Expr
Returns:
result of check