org.basex.query.expr
Class Cast
java.lang.Object
org.basex.query.ExprInfo
org.basex.query.expr.Expr
org.basex.query.expr.Single
org.basex.query.expr.Cast
public final class Cast
- extends Single
Cast expression.
- 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 |
Fields inherited from class org.basex.query.expr.Single |
expr |
Methods inherited from class org.basex.query.expr.Expr |
addText, checkCtx, checkDbl, checkItr, duplicates, e, ebv, i, indexAccessible, indexEquivalent, iter, removable, sameAs, size, test, v |
Cast
public Cast(Expr e,
SeqType t)
- Function constructor.
- Parameters:
e
- expressiont
- data type
comp
public Expr comp(QueryContext ctx)
throws QueryException
- Description copied from class:
Expr
- Optimizes and compiles the expression.
- Overrides:
comp
in class Single
- 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
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 Single
- Parameters:
ser
- serializer
- Throws:
IOException
- I/O exception
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
info
public String info()
- Description copied from class:
ExprInfo
- Returns a string description of the expression. Contrary to the
ExprInfo.toString()
method, arguments are not included
in the output.
- Overrides:
info
in class ExprInfo
- Returns:
- result of check
toString
public String toString()
- Specified by:
toString
in class ExprInfo