org.basex.query.ft
Class FTContains

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.expr.Expr
          org.basex.query.ft.FTContains

Direct Known Subclasses:

FTContainsSIndex

public class FTContains
extends Expr

FTContains expression.

Author:

Workgroup DBIS, University of Konstanz 2005-09, ISC License, Christian Gruen

Field Summary

Expr	expr Expression.
FTTokenizer	ft Fulltext parser.
FTExpr	ftexpr Fulltext expression.

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.
java.lang.String	color() Returns a string description of the expression.
Expr	comp(QueryContext ctx) Optimizes and compiles the expression.
void	indexAccessible(QueryContext ctx, IndexContext ic) Checks if an index can be used for query evaluation.
Expr	indexEquivalent(QueryContext ctx, 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.
Expr	remove(Var v) Removes the specified variable in a sub expression.
Return	returned(QueryContext ctx) Indicates the return type of an expression.
java.lang.String	toString()
boolean	uses(Expr.Use use, 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, removable, sameAs, size, test

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

Field Detail

expr

public Expr expr

Expression.

ftexpr

public FTExpr ftexpr

Fulltext expression.

ft

public FTTokenizer ft

Fulltext parser.

Constructor Detail

FTContains

public FTContains(Expr e,
                  FTExpr fte)

Constructor.

Parameters:

e - expression

fte - fulltext expression

Method Detail

comp

public 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 - evaluation 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 void indexAccessible(QueryContext ctx,
                            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:

ctx - query context

ic - index context

Throws:

QueryException - Exception

indexEquivalent

public Expr indexEquivalent(QueryContext ctx,
                            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.QueryContext, org.basex.query.IndexContext) is implemented for an expression.

Overrides:

indexEquivalent in class Expr

Parameters:

ctx - query context

ic - index context

Returns:

Equivalent index-expression or null

Throws:

QueryException - Exception

uses

public boolean uses(Expr.Use use,
                    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 Expr

Parameters:

use - use type to be checked

ctx - query context

Returns:

result of check

remove

public 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 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 java.lang.String color()

Description copied from class: ExprInfo

Returns a string description of the expression. Contrary to the ExprInfo.toString() method, the current expressions aren't included in the output.

Overrides:

color in class ExprInfo

Returns:

result of check

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.

Specified by:

plan in class ExprInfo

Parameters:

ser - serializer

Throws:

java.io.IOException - exception

toString

public java.lang.String toString()

Specified by:

toString in class ExprInfo