org.extex.unit.dynamic
Class NativeLoad

java.lang.Object
  org.extex.interpreter.type.AbstractCode
      org.extex.unit.dynamic.NativeLoad

All Implemented Interfaces:

java.io.Serializable, Configurable, LogEnabled, Code

public class NativeLoad
extends AbstractCode
implements Configurable, LogEnabled

This primitive initiates the loading of native code and implements the primitive \nativeload.

The Primitive \nativeload

The primitive \nativeload loads some native language code. As parameter the type of the native extension and a specification of the loader to be used are given.

With this method it is possible to load larger extensions of ExTeX in one junk. There is no need to declare each single macro with \def. It is even possible to define extension macros in other programming languages than the TeX language.

Syntax

The general form of this primitive is

 
    ⟨nativeload⟩
      → \nativeload ⟨type⟩ ⟨tokens⟩ 

The ⟨type⟩ is any specification of a list of tokens like a constant list enclosed in braces or a token register. The value of these tokens are taken and resolved via the configuration.

The ⟨tokens⟩ is any specification of a list of tokens like a constant list enclosed in braces or a tokens register. For the Java loader the value of these tokens are taken and interpreted as the name of a Java class. This class is loaded if needed, instantiated, and its method init() is invoked. The instantiation requires the empty constructor to be visible.

Examples

The following example illustrates the use of this primitive:

   \nativeload{java}{my.unit.MyUnitLoader} 

For the loading of the Java class it is necessary that this Java class implements the interface Loadable.

 package my.package;
 
 import org.extex.interpreter.context.Context;
 import org.extex.interpreter.primitives.dynamic.java.Loadable;
 import org.extex.typesetter.Typesetter;
 import org.extex.util.exception.GeneralException;
 
 class MyModule implements Loadable {
 
     public MyModule() {
         super();
         // initialization code – if required
     }
 
     public void init(final Context context, final Typesetter
 typesetter )
         throws GeneralException {
             // implement the initialization code here
     }
 } 

Configuration

The supported types are determined in the configuration of the unit which defines the primitive. Here a mapping is specified assigning a binding class for each supported type. Thus it is possible to configure in the support for several extension types. Currently a binding for Java is provided. In the future other languages can be added easily.

 <define name="nativeload"
         class="org.extex.interpreter.primitives.dynamic.NativeLoad">
   <load name="java"
         class="org.extex.interpreter.primitives.dynamic.java.JavaLoad"/>
 </define> 

The body of the define tag for the primitive may contain an arbitrary number of load sections. Each load has the attribute name and class. The attribute name determines the type. This corresponds to the type given in the first argument of the primitive invocation.

The class attribute names the class which provides the binding to the target programming language.

Version:

$Revision: 7371 $

Author:

Gerd Neugebauer

See Also:

Serialized Form

Field Summary

protected static long

serialVersionUID The constant serialVersionUID contains the id for serialization.

Constructor Summary

NativeLoad(CodeToken token)
Creates a new object.

Method Summary

void	configure(Configuration config) Configure an object according to a given Configuration.
void	enableLogging(java.util.logging.Logger log) Setter for the logger.
void	execute(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method takes the first token and executes it. The result is placed on the stack. This operation might have side effects. To execute a token it might be necessary to consume further tokens.
protected java.util.logging.Logger	getLogger() Getter for logger.

Methods inherited from class org.extex.interpreter.type.AbstractCode

getLocalizer, getName, getToken, isIf, isOuter, readResolve, toString, toText, toText

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

serialVersionUID

protected static final long serialVersionUID

The constant serialVersionUID contains the id for serialization.

See Also:

Constant Field Values

Constructor Detail

NativeLoad

public NativeLoad(CodeToken token)

Creates a new object.

Parameters:

token - the initial token for the primitive

Method Detail

configure

public void configure(Configuration config)
               throws ConfigurationException

Configure an object according to a given Configuration.

Specified by:

configure in interface Configurable

Parameters:

config - the configuration object to consider

Throws:

ConfigurationException - in case that something went wrong

See Also:

Configurable.configure(org.extex.framework.configuration.Configuration)

enableLogging

public void enableLogging(java.util.logging.Logger log)

Setter for the logger.

Specified by:

enableLogging in interface LogEnabled

Parameters:

log - the logger to use

See Also:

LogEnabled.enableLogging(java.util.logging.Logger)

execute

public void execute(Flags prefix,
                    Context context,
                    TokenSource source,
                    Typesetter typesetter)
             throws HelpingException,
                    TypesetterException

This method takes the first token and executes it. The result is placed on the stack. This operation might have side effects. To execute a token it might be necessary to consume further tokens.

Specified by:

execute in interface Code

Overrides:

execute in class AbstractCode

Parameters:

prefix - the prefix controlling the execution

context - the interpreter context

source - the token source

typesetter - the typesetter

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

See Also:

AbstractCode.execute(org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)

getLogger

protected java.util.logging.Logger getLogger()

Getter for logger.

Returns:

the logger