org.extex.unit.tex.register.box
Class Setbox

java.lang.Object
  org.extex.interpreter.type.AbstractCode
      org.extex.interpreter.type.AbstractAssignment
          org.extex.unit.tex.register.box.Setbox

All Implemented Interfaces:

java.io.Serializable, Code

public class Setbox
extends AbstractAssignment

This class provides an implementation for the primitive \setbox.

The Primitive \setbox

The primitive \setbox takes a key for a box register and assigns the following box to this register.

TODO missing documentation

The primitive is an assignment. This means that it respects \globaldefs. The treatment of \afterassignment is special The token stored for after assignment are inserted just after the box as been opened.

Syntax

The formal description of this primitive is the following:

    ⟨setbox⟩
      → ⟨optional prefix⟩ \setbox ⟨box register name⟩ ⟨box⟩

    ⟨optional prefix⟩
      →
       |  \global ⟨optional prefix⟩  

Examples

    \setbox0\hbox{abc}  

Version:

$Revision:4431 $

Author:

Gerd Neugebauer

See Also:

Serialized Form

Field Summary

protected static long

serialVersionUID The constant serialVersionUID contains the id for serialization.

Constructor Summary

Setbox(CodeToken token)
Creates a new object.

Method Summary

void	assign(Flags prefix, Context context, TokenSource source, Typesetter typesetter) The method assign is the core of the functionality of execute().
static java.lang.String	getKey(Context context, TokenSource source, Typesetter typesetter, CodeToken primitive) Return the key (the number) for the box register.

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

execute

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

Setbox

public Setbox(CodeToken token)

Creates a new object.

Parameters:

token - the initial token for the primitive

Method Detail

getKey

public static java.lang.String getKey(Context context,
                                      TokenSource source,
                                      Typesetter typesetter,
                                      CodeToken primitive)
                               throws HelpingException,
                                      TypesetterException

Return the key (the number) for the box register.

A Box Register Name

A box register name determines under which key a box register can be addressed. In TeX this used to be a positive number only. This has been extended to allow also a token list in braces.

The alternative is controlled by the count register \register.max. The following interpretation of the value of this count is used:

• If the value of this count register is negative then a arbitrary non-negative number is allowed as register name as well as any list of tokens enclosed in braces.
• If the value of this count register is not-negative then a only a non-negative number is allowed as register name which does not exceed the value of the count register.

The value of the count register \register.max is set differently for various configurations of ExTeX:

• TeX uses the value 255.
• eTeX uses the value 32767.
• Omega uses the value 65536.
• ExTeX uses the value -1.

Note that the register name \register.max contains a period. Thus it can normally not be entered easily since the catcode of the period is OTHER but needs to be LETTER. Thus you have to use a temporarily reassigned category code (see \catcode) or use \csname.

Syntax

   ⟨box register name⟩
       → ⟨tokens⟩
        | ⟨number⟩  

Examples

  123
  {abc}
 

Parameters:

context - the interpreter context to use

source - the source for new tokens

typesetter - the typesetter

primitive - the name of the primitive for error messages

Returns:

the key for the box register

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

assign

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

The method assign is the core of the functionality of execute(). This method is preferable to execute() since the execute() method provided in this class takes care of \afterassignment and \globaldefs as well.

Specified by:

assign in class AbstractAssignment

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:

AbstractAssignment.assign( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)