org.basex.query.func
Class FNInfo

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.Arr
                  extended by org.basex.query.func.StandardFunc
                      extended by org.basex.query.func.FNInfo

public final class FNInfo
extends StandardFunc

Info 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.Flag
 
Field Summary
 
Fields inherited from class org.basex.query.expr.Arr
expr
 
Fields inherited from class org.basex.query.expr.ParseExpr
info, size, type
 
Constructor Summary
FNInfo(InputInfo ii, Function f, Expr... e)
          Constructor.
 
Method Summary
static void dump(byte[] value, byte[] label, QueryContext ctx)
          Dumps the specified info to standard error or the info view of the GUI.
static FNInfo error(QueryException ex)
          Creates an error function instance.
 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.
 Iter iter(QueryContext ctx)
          Evaluates the expression and returns an iterator on the resulting items.
protected  Expr opt(QueryContext ctx)
          Performs function specific optimizations.
 
Methods inherited from class org.basex.query.func.StandardFunc
atom, bindings, cache, checkData, checkFile, compile, copy, dataLock, dateTimeToMs, description, encoding, has, isFunction, isVacuous, oneOf, optimize, plan, toString
 
Methods inherited from class org.basex.query.expr.Arr
accept, allAreValues, checkNoUp, checkUp, copyAll, count, exprSize, indexEquivalent, inline, removable, toString
 
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, optPre, preEval, size, test, type, value
 
Methods inherited from class org.basex.query.expr.Expr
addText, compEbv, copy, hasFreeVars, indexAccessible, inlineAll, isEmpty, isItem, isValue, iterable, markTailCalls, sameAs, uses, visitAll
 
Methods inherited from class org.basex.data.ExprInfo
addPlan, addPlan, info, planAttr, planElem
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FNInfo

public FNInfo(InputInfo ii,
              Function f,
              Expr... e)
Constructor.

Parameters:
ii - input info
f - function definition
e - arguments
Method Detail

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.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

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

opt

protected Expr opt(QueryContext ctx)
            throws QueryException
Description copied from class: StandardFunc
Performs function specific optimizations.

Overrides:
opt in class StandardFunc
Parameters:
ctx - query context
Returns:
evaluated item
Throws:
QueryException - query exception

dump

public static void dump(byte[] value,
                        byte[] label,
                        QueryContext ctx)
Dumps the specified info to standard error or the info view of the GUI.

Parameters:
value - traced value
label - additional label to display (can be null)
ctx - query context

error

public static FNInfo error(QueryException ex)
Creates an error function instance.

Parameters:
ex - query exception
Returns:
function