org.basex.query.up
Class Transform
java.lang.Object
org.basex.query.ExprInfo
org.basex.query.expr.Expr
org.basex.query.expr.Arr
org.basex.query.up.Transform
public final class Transform
- extends Arr
Transform expression.
- Author:
- Workgroup DBIS, University of Konstanz 2005-10, ISC License, Lukas Kircher
Nested classes/interfaces inherited from class org.basex.query.expr.Expr |
Expr.Use |
Fields inherited from class org.basex.query.expr.Arr |
expr |
Methods inherited from class org.basex.query.expr.Expr |
addText, checkCtx, checkDbl, checkItr, e, ebv, i, indexAccessible, iter, returned, sameAs, size, test, v |
Transform
public Transform(Let[] c,
Expr m,
Expr r)
- Constructor.
- Parameters:
c
- copy expressionsm
- modify expressionr
- return expression
comp
public Expr comp(QueryContext ctx)
throws QueryException
- Description copied from class:
Expr
- Optimizes and compiles the expression.
- Overrides:
comp
in class Arr
- Parameters:
ctx
- query context
- Returns:
- optimized Expression
- 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
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 checkedctx
- query context
- Returns:
- result of check
plan
public void plan(Serializer ser)
throws IOException
- Description copied from class:
ExprInfo
- Recursively sends the abstract syntax of this expression to the
specified serializer.
- Overrides:
plan
in class Arr
- Parameters:
ser
- serializer
- Throws:
IOException
- I/O exception
toString
public String toString()
- Specified by:
toString
in class ExprInfo