org.basex.query.expr
Class IndexAccess

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.expr.Expr
          org.basex.query.expr.Single
              org.basex.query.expr.IndexAccess

public final class IndexAccess
extends Single

This index class retrieves texts and attribute values from the index.

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

IndexAccess(Expr e, Data.Type t, IndexContext ic)
Constructor.

Method Summary

String	color() Returns a color string for the expression.
boolean	duplicates(QueryContext ctx) Returns true if the expression might yield duplicates and unsorted results.
Iter	iter(QueryContext ctx) Evaluates the expression and returns an iterator on the resulting items.
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.
boolean	sameAs(Expr cmp) Checks the current and specified expression for equality.
String	toString()

Methods inherited from class org.basex.query.expr.Single

comp, remove, uses

Methods inherited from class org.basex.query.expr.Expr

addText, atomic, checkCtx, checkDbl, checkItr, e, ebv, i, indexAccessible, indexEquivalent, removable, 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

IndexAccess

public IndexAccess(Expr e,
                   Data.Type t,
                   IndexContext ic)

Constructor.

Parameters:

e - index expression

t - access type

ic - index context

Method Detail

iter

public Iter iter(QueryContext ctx)
          throws QueryException

Description copied from class: Expr

Evaluates the expression and returns an iterator on the resulting items. If this method is not overwritten, Expr.atomic(org.basex.query.QueryContext) must be implemented.

Overrides:

iter in class Expr

Parameters:

ctx - query context

Returns:

resulting item

Throws:

QueryException - query 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

duplicates

public boolean duplicates(QueryContext ctx)

Description copied from class: Expr

Returns true if the expression might yield duplicates and unsorted results.

Overrides:

duplicates in class Expr

Parameters:

ctx - query context

Returns:

result of check

sameAs

public boolean sameAs(Expr cmp)

Description copied from class: Expr

Checks the current and specified expression for equality.

Overrides:

sameAs in class Expr

Parameters:

cmp - expression to be compared

Returns:

result of check

color

public String color()

Description copied from class: ExprInfo

Returns a color string for the expression.

Overrides:

color in class ExprInfo

Returns:

color

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

toString

public String toString()

Specified by:

toString in class ExprInfo