org.basex.query
Class QueryContext

java.lang.Object
  org.basex.core.Progress
      org.basex.query.QueryContext

Direct Known Subclasses:

XPContext, XQContext

public abstract class QueryContext
extends Progress

This abstract query expression provides the architecture for a compiled query.

Author:

Workgroup DBIS, University of Konstanz 2005-07, ISC License, Christian Gruen

Constructor Summary

QueryContext()

Method Summary

abstract void	compile(Nodes nodes) Optimizes the expression.
void	compInfo(java.lang.String string, java.lang.Object... ext) Adds some optimization info.
java.lang.String	det() Returns detailed information on this progress.
abstract Result	eval(Nodes nodes) Evaluates the expression with the specified context set.
void	evalInfo(java.lang.String string, java.lang.Object... ext) Adds some evaluation info.
java.lang.String	head() Returns short information on this process.
java.lang.String	info() Returns query background information.
double	prog() Returns progress information.

Methods inherited from class org.basex.core.Progress

detail, header, progress, progress, stop, stopped

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QueryContext

public QueryContext()

Method Detail

compile

public abstract void compile(Nodes nodes)
                      throws EvalException

Optimizes the expression.

Parameters:

nodes - node context

Throws:

EvalException - evaluation exception

compInfo

public final void compInfo(java.lang.String string,
                           java.lang.Object... ext)

Adds some optimization info.

Parameters:

string - evaluation info

ext - text text extensions

det

public final java.lang.String det()

Description copied from class: Progress

Returns detailed information on this progress.

Returns:

information in detail

eval

public abstract Result eval(Nodes nodes)
                     throws EvalException

Evaluates the expression with the specified context set.

Parameters:

nodes - initial context set

Returns:

resulting value

Throws:

EvalException - evaluation exception

evalInfo

public final void evalInfo(java.lang.String string,
                           java.lang.Object... ext)

Adds some evaluation info.

Parameters:

string - evaluation info

ext - text text extensions

head

public final java.lang.String head()

Description copied from class: Progress

Returns short information on this process.

Returns:

header information

info

public final java.lang.String info()

Returns query background information.

Returns:

warning

prog

public final double prog()

Description copied from class: Progress

Returns progress information.

Returns:

header information