org.basex.query.func

Class FNAggr

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.func.StandardFunc

org.basex.query.func.FNAggr

public final class FNAggr
extends StandardFunc

Aggregating functions.

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
FNAggr(InputInfo ii, Function f, Expr... e) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
Expr	cmp(QueryContext ctx) Performs function specific compilations.
Item	item(QueryContext ctx, InputInfo ii) Evaluates the expression and returns the resulting item or a null reference, if the expression yields an empty sequence.

Methods inherited from class org.basex.query.func.StandardFunc

atom, comp, description, isFunction, plan, toString

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

allAreValues, count, indexEquivalent, 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, indexAccessible, isEmpty, isItem, isVacuous, isValue, iterable, markTailCalls, sameAs

Methods inherited from class org.basex.data.ExprInfo

info

Methods inherited from class java.lang.Object

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

Constructor Detail

FNAggr

public FNAggr(InputInfo ii,
      Function f,
      Expr... e)

Constructor.

Parameters:

ii - input info

f - function definition

e - arguments

Method Detail

item

public Item 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

cmp

public Expr cmp(QueryContext ctx)
         throws QueryException

Description copied from class: StandardFunc

Performs function specific compilations.

Parameters:

ctx - query context

Returns:

evaluated item

Throws:

QueryException - query exception