Class Discretionary

  extended byde.dante.extex.interpreter.type.AbstractCode
      extended byde.dante.extex.interpreter.primitives.hyphen.Discretionary
All Implemented Interfaces:
Code, Localizable,

public class Discretionary
extends AbstractCode

This class provides an implementation for the primitive \discretionary.

The Primitive \discretionary

The primitive \discretionary can be used to insert an optional break point into the paragraph. The optional break point consists of three parts. The first part is inserted into the paragraph if no line breaking happens at this position. In case that the line breaking chooses this place for a line break then the second part of the discretionary is inserted at the end of the current line and the third part is inserted at the beginning of the next line.

The three parts are given as three sequences of characters in braces. It may be composed of characters, ligatures, and rules only.

In math mode the third part is forced to be empty.


The formal description of this primitive is the following:
      → \discretionary{...}{...}{...}  



$Revision: 1.30 $
Gerd Neugebauer
See Also:
Serialized Form

Field Summary
protected static long serialVersionUID
          The constant serialVersionUID contains the id for serialization.
Constructor Summary
Discretionary(java.lang.String name)
          Creates a new object.
Method Summary
 void execute(Flags prefix, Context context, TokenSource source, Typesetter typesetter)
          This method takes the first token and executes it.
Methods inherited from class de.dante.extex.interpreter.type.AbstractCode
enableLocalization, getLocalizer, getName, isIf, isOuter, printable, printableControlSequence, readResolve, setName, toString
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail


protected static final long serialVersionUID
The constant serialVersionUID contains the id for serialization.

See Also:
Constant Field Values
Constructor Detail


public Discretionary(java.lang.String name)
Creates a new object.

name - the name for debugging
Method Detail


public void execute(Flags prefix,
                    Context context,
                    TokenSource source,
                    Typesetter typesetter)
             throws InterpreterException
Description copied from interface: Code
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
execute in class AbstractCode
See Also:
Code.execute( de.dante.extex.interpreter.Flags, de.dante.extex.interpreter.context.Context, de.dante.extex.interpreter.TokenSource, de.dante.extex.typesetter.Typesetter)