org.basex.query.expr
Class Root
java.lang.Object
org.basex.query.ExprInfo
org.basex.query.expr.Expr
org.basex.query.expr.Simple
org.basex.query.expr.Root
public final class Root
- extends Simple
Root node.
- Author:
- Workgroup DBIS, University of Konstanz 2005-10, ISC License, Christian Gruen
Nested classes/interfaces inherited from class org.basex.query.expr.Expr |
Expr.Use |
Constructor Summary |
Root()
|
Methods inherited from class org.basex.query.expr.Expr |
addText, atomic, checkCtx, checkDbl, checkItr, duplicates, e, ebv, i, indexAccessible, indexEquivalent, removable, remove, size, test, v |
Root
public Root()
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
root
public Nod root(Item i)
- Returns the root node of the specified item.
- Parameters:
i
- input node
- Returns:
- root node
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 Simple
- Parameters:
u
- use type to be checkedctx
- query context
- Returns:
- result of check
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
sameAs
public boolean sameAs(Expr cmp)
- Description copied from class:
Expr
- Checks the current and specified expression for equality.
- Overrides:
sameAs
in class Expr
- Parameters:
cmp
- expression to be compared
- Returns:
- result of check
toString
public String toString()
- Specified by:
toString
in class ExprInfo