org.basex.query.expr
Class Cast

java.lang.Object
  extended by org.basex.query.ExprInfo
      extended by org.basex.query.expr.Expr
          extended by org.basex.query.expr.Single
              extended by 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 Class Summary
 
Nested classes/interfaces inherited from class org.basex.query.expr.Expr
Expr.Use
 
Field Summary
 
Fields inherited from class org.basex.query.expr.Single
expr
 
Constructor Summary
Cast(Expr e, SeqType t)
          Function constructor.
 
Method Summary
 Item atomic(QueryContext ctx)
          Evaluates the expression and returns the resulting item or a null reference.
 Expr comp(QueryContext ctx)
          Optimizes and compiles the expression.
 String info()
          Returns a string description of the expression.
 void plan(Serializer ser)
          Recursively sends the abstract syntax of this expression to the specified serializer.
 Return returned(QueryContext ctx)
          Indicates the return type of an expression.
 String toString()
           
 
Methods inherited from class org.basex.query.expr.Single
remove, uses
 
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
 
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

Cast

public Cast(Expr e,
            SeqType t)
Function constructor.

Parameters:
e - expression
t - data type
Method Detail

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