org.basex.query.func
Class FNGen

java.lang.Object
  extended by org.basex.query.ExprInfo
      extended by org.basex.query.expr.Expr
          extended by org.basex.query.expr.Arr
              extended by org.basex.query.func.Fun
                  extended by org.basex.query.func.FNGen

public final class FNGen
extends Fun

Generating functions.

Author:
Workgroup DBIS, University of Konstanz 2005-10, ISC 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.func.Fun
func
 
Fields inherited from class org.basex.query.expr.Arr
expr
 
Constructor Summary
FNGen()
           
 
Method Summary
 Item atomic(QueryContext ctx)
          Evaluates the expression and returns the resulting item or a null reference.
 Expr c(QueryContext ctx)
          Compiles the function.
 Iter iter(QueryContext ctx)
          Evaluates the expression and returns an iterator on the resulting items.
 boolean uses(Expr.Use u, QueryContext ctx)
          Indicates if an expression uses the specified type.
 
Methods inherited from class org.basex.query.func.Fun
comp, info, init, plan, returned, toString
 
Methods inherited from class org.basex.query.expr.Arr
duplicates, indexEquivalent, removable, remove
 
Methods inherited from class org.basex.query.expr.Expr
addText, checkCtx, checkDbl, checkItr, e, ebv, i, indexAccessible, sameAs, size, test, v
 
Methods inherited from class org.basex.query.ExprInfo
color, name
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FNGen

public FNGen()
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.atomic(org.basex.query.QueryContext) must be implemented.

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

atomic

public Item 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

c

public Expr c(QueryContext ctx)
       throws QueryException
Description copied from class: Fun
Compiles the function.

Overrides:
c in class Fun
Parameters:
ctx - query context
Returns:
evaluated item
Throws:
QueryException - query exception

uses

public boolean uses(Expr.Use u,
                    QueryContext ctx)
Description copied from class: Expr
Indicates if an expression uses the specified type. Called by the compiler to perform certain optimizations. true is returned by default and thus assumed as "worst-case".

Overrides:
uses in class Arr
Parameters:
u - use type to be checked
ctx - query context
Returns:
result of check