org.extex.unit.omega.ocp
Class Nullocplist

java.lang.Object
  extended by org.extex.interpreter.type.AbstractCode
      extended by org.extex.unit.omega.ocp.Nullocplist
All Implemented Interfaces:
java.io.Serializable, Code, Showable, OcplistConvertible

public class Nullocplist
extends AbstractCode
implements Showable, OcplistConvertible

This class provides an implementation for the primitive \nullocplist.

The Primitive \nullocplist

The primitive \nullocplist can be used to build up an ΩPC list. It is valid in the context of the primitive \ocplist only.

Syntax

The formal description of this primitive is the following:
    ⟨nullocplist⟩
      → \nullocplist  

Examples

 \nullocplist 

Version:
$Revision: 4732 $
Author:
Gerd Neugebauer
See Also:
Serialized Form

Constructor Summary
Nullocplist(CodeToken token)
          Creates a new object.
 
Method Summary
 OcpList convertOcplist(Context context, TokenSource source, Typesetter typesetter)
          Convert the value into an ΩPC list.
 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.
 Tokens show(Context context)
          This method is the getter for the description of the primitive.
 
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
 

Constructor Detail

Nullocplist

public Nullocplist(CodeToken token)
Creates a new object.

Parameters:
token - the initial token for the primitive
Method Detail

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)

show

public Tokens show(Context context)
            throws HelpingException
This method is the getter for the description of the primitive.

Specified by:
show in interface Showable
Parameters:
context - the interpreter context
Returns:
the description of the primitive as list of Tokens
Throws:
HelpingException - in case of an error
See Also:
Showable.show( org.extex.interpreter.context.Context)

convertOcplist

public OcpList convertOcplist(Context context,
                              TokenSource source,
                              Typesetter typesetter)
                       throws HelpingException
Convert the value into an ΩPC list. Some tokens may be read from the input stream to perform the job.

Specified by:
convertOcplist in interface OcplistConvertible
Parameters:
context - the interpreter context
source - the source for new tokens
typesetter - the typesetter
Returns:
the ΩPC list encountered
Throws:
HelpingException - in case of an error
See Also:
OcplistConvertible.convertOcplist( org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)