org.extex.unit.tex.macro
Class Csname

java.lang.Object
  org.extex.interpreter.type.AbstractCode
      org.extex.unit.tex.macro.Csname

All Implemented Interfaces:

java.io.Serializable, Code, ExpandableCode, PrefixCode

public class Csname
extends AbstractCode
implements ExpandableCode, PrefixCode

This class provides an implementation for the primitive \csname.

The Primitive \csname

The primitive \csname absorbs further tokens until a matching \endcsname is found. The tokens found are expanded. Spaces are ignored. The expansion should lead to character tokens only. No primitives producing something different are allowed. A new token is constructed from the characters. The escape character is the current escape character.

If the meaning of the new token is currently not defined then it is defined to be equivalent to the original meaning of \relax.

If a non-expandable token is encountered then an error is raised.

Syntax

The formal description of this primitive is the following:

    ⟨csname⟩
      → \csname ⟨expandable tokens⟩ \endcsname  

Examples

    \csname abc\endcsname  

This results in the control sequence \abc.

    \csname ab#de\endcsname  

The example is valid. It shows that even non-character tokens might be contained.

    \csname \TeX\endcsname  

This is usually illegal since \TeX is defined in plain to contain some non-expandable primitives.

Version:

$Revision: 4770 $

Author:

Gerd Neugebauer

See Also:

Serialized Form

Field Summary

protected static long

serialVersionUID The constant serialVersionUID contains the id for serialization.

Constructor Summary

Csname(CodeToken token)
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.
void	expand(Flags prefix, Context context, TokenSource source, Typesetter typesetter) This method takes the first token and expands it.
static java.lang.String	scanToEndCsname(Context context, TokenSource source, Typesetter typesetter, Localizer loc) Expand tokens and collect the result until \endcsname is found.

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

Csname

public Csname(CodeToken token)

Creates a new object.

Parameters:

token - the initial token for the primitive

Method Detail

scanToEndCsname

public static java.lang.String scanToEndCsname(Context context,
                                               TokenSource source,
                                               Typesetter typesetter,
                                               Localizer loc)
                                        throws HelpingException,
                                               ConfigurationException,
                                               TypesetterException

Expand tokens and collect the result until \endcsname is found. In fact the termination condition is that a Token is found which is assigned to Endcsname.

Parameters:

context - the interpreter context

source - the source for new tokens

typesetter - the typesetter

loc - the localizer

Returns:

the Tokens found while scanning the input tokens

Throws:

HelpingException - in case of an error

TypesetterException - in case of an error in the typesetter

ConfigurationException - in case of an configuration error

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:

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

expand

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

This method takes the first token and expands it. The result is placed on the stack. This means that expandable code does one step of expansion and puts the result on the stack. To expand a token it might be necessary to consume further tokens.

Specified by:

expand in interface ExpandableCode

Parameters:

prefix - the prefix flags controlling the expansion

context - the interpreter context

source - the token source

typesetter - the typesetter

Throws:

HelpingException - in case of an error

ConfigurationException - in case of an configuration error

TypesetterException - in case of an error in the typesetter

See Also:

ExpandableCode.expand( org.extex.interpreter.Flags, org.extex.interpreter.context.Context, org.extex.interpreter.TokenSource, org.extex.typesetter.Typesetter)