org.basex.query.ft
Class FTContains

java.lang.Object
  extended by org.basex.query.ExprInfo
      extended by org.basex.query.expr.Expr
          extended by org.basex.query.ft.FTContains
Direct Known Subclasses:
FTContainsIndex

public class FTContains
extends Expr

FTContains 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
 
Constructor Summary
FTContains(Expr e, FTExpr fte)
          Constructor.
 
Method Summary
 Bln atomic(QueryContext ctx)
          Evaluates the expression and returns the resulting item or a null reference.
 String color()
          Returns a color string for the expression.
 Expr comp(QueryContext ctx)
          Optimizes and compiles the expression.
 boolean indexAccessible(IndexContext ic)
          Checks if an index can be used for query evaluation.
 Expr indexEquivalent(IndexContext ic)
          Returns an equivalent expression which accesses an index structure.
 void plan(Serializer ser)
          Recursively sends the abstract syntax of this expression to the specified serializer.
 boolean removable(Var v, QueryContext ctx)
          Checks if the specified variable is removable.
 Expr remove(Var v)
          Removes the specified variable in a sub expression.
 Return returned(QueryContext ctx)
          Indicates the return type of an expression.
 String toString()
           
 boolean uses(Expr.Use u, QueryContext ctx)
          Indicates if an expression uses the specified type.
 
Methods inherited from class org.basex.query.expr.Expr
addText, checkCtx, checkDbl, checkItr, duplicates, e, ebv, i, iter, sameAs, size, test, v
 
Methods inherited from class org.basex.query.ExprInfo
info, name
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FTContains

public FTContains(Expr e,
                  FTExpr fte)
Constructor.

Parameters:
e - expression
fte - full-text expression
Method Detail

comp

public final Expr comp(QueryContext ctx)
                throws QueryException
Description copied from class: Expr
Optimizes and compiles the expression.

Specified by:
comp in class Expr
Parameters:
ctx - query context
Returns:
optimized Expression
Throws:
QueryException - query exception

atomic

public Bln 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

indexAccessible

public final boolean indexAccessible(IndexContext ic)
                              throws QueryException
Description copied from class: Expr
Checks if an index can be used for query evaluation.

Overrides:
indexAccessible in class Expr
Parameters:
ic - index context
Returns:
true if an index can be used
Throws:
QueryException - query exception

indexEquivalent

public final Expr indexEquivalent(IndexContext ic)
                           throws QueryException
Description copied from class: Expr
Returns an equivalent expression which accesses an index structure. Must be called if Expr.indexAccessible(org.basex.query.IndexContext) is implemented for an expression.

Overrides:
indexEquivalent in class Expr
Parameters:
ic - index context
Returns:
Equivalent index-expression or null
Throws:
QueryException - query exception

uses

public final 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".

Specified by:
uses in class Expr
Parameters:
u - use type to be checked
ctx - query context
Returns:
result of check

removable

public final boolean removable(Var v,
                               QueryContext ctx)
Description copied from class: Expr
Checks if the specified variable is removable.

Overrides:
removable in class Expr
Parameters:
v - variable to be removed
ctx - query context
Returns:
result of check

remove

public final Expr remove(Var v)
Description copied from class: Expr
Removes the specified variable in a sub expression.

Overrides:
remove in class Expr
Parameters:
v - variable to be removed
Returns:
expression with removed variable

returned

public final 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

color

public final String color()
Description copied from class: ExprInfo
Returns a color string for the expression.

Overrides:
color in class ExprInfo
Returns:
color

plan

public final void plan(Serializer ser)
                throws IOException
Description copied from class: ExprInfo
Recursively sends the abstract syntax of this expression to the specified serializer.

Specified by:
plan in class ExprInfo
Parameters:
ser - serializer
Throws:
IOException - I/O exception

toString

public String toString()
Specified by:
toString in class ExprInfo