org.basex.query.xpath.expr
Class Cmp

java.lang.Object
  extended by org.basex.query.ExprInfo
      extended by org.basex.query.xpath.expr.Expr
          extended by org.basex.query.xpath.expr.Arr
              extended by org.basex.query.xpath.expr.Cmp
Direct Known Subclasses:
Equality, Relational

public abstract class Cmp
extends Arr

Abstract Compare Expression.

Author:
Workgroup DBIS, University of Konstanz 2005-08, ISC License, Christian Gruen

Field Summary
 Comp type
          Expression Type.
 
Fields inherited from class org.basex.query.xpath.expr.Arr
expr
 
Constructor Summary
Cmp(Expr e1, Expr e2)
          Constructor.
 
Method Summary
 Expr comp(XPContext ctx)
          Optimizes the expression.
 Bln eval(XPContext ctx)
          Evaluates the expression with the specified context set.
 void plan(Serializer ser)
          Recursively sends the abstract syntax of this expression to the specified serializer.
 boolean standard()
          Checks if this expression has a location path and Item as arguments.
 java.lang.String toString()
           
 
Methods inherited from class org.basex.query.xpath.expr.Arr
sameAs, usesPos, usesSize
 
Methods inherited from class org.basex.query.xpath.expr.Expr
indexEquivalent, indexSizes, returnedValue
 
Methods inherited from class org.basex.query.ExprInfo
color, info, name
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

type

public Comp type
Expression Type.

Constructor Detail

Cmp

public Cmp(Expr e1,
           Expr e2)
Constructor.

Parameters:
e1 - first expression
e2 - second expression to compare with first
Method Detail

comp

public Expr comp(XPContext ctx)
          throws QueryException
Description copied from class: Expr
Optimizes the expression.

Overrides:
comp in class Arr
Parameters:
ctx - expression context
Returns:
optimized Expression
Throws:
QueryException - evaluation exception

eval

public final Bln eval(XPContext ctx)
               throws QueryException
Description copied from class: Expr
Evaluates the expression with the specified context set. Additionally provides a context

Specified by:
eval in class Expr
Parameters:
ctx - query context
Returns:
resulting XPathValue
Throws:
QueryException - evaluation exception

standard

public final boolean standard()
Checks if this expression has a location path and Item as arguments.

Returns:
result of check

toString

public final java.lang.String toString()
Specified by:
toString in class ExprInfo

plan

public void plan(Serializer ser)
          throws java.io.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:
java.io.IOException - exception