de.dante.extex.interpreter.primitives.macro
Class Expandafter

java.lang.Object
  de.dante.extex.interpreter.type.AbstractCode
      de.dante.extex.interpreter.primitives.macro.Expandafter

All Implemented Interfaces:

Code, ExpandableCode, Localizable, java.io.Serializable

public class Expandafter

extends AbstractCode

implements ExpandableCode

This class provides an implementation for the primitive \expandafter.

The Primitive \expandafter

The primitive \expandafter reverses the expansion of the following two tokens. For this purpose the next token following the invocation is read unexpanded and put aside. Then the next token is expanded in whatever way the token requires expansion. This may involve the reading and expansion of further tokens. When this expansion is finished then the saved token is put back into the input stream.

Any prefix argument is saved for the expansion of the following token.

Syntax

    ⟨expandafter⟩
     → \expandafter ⟨control sequence⟩ ...  

Examples

    \expandafter ab  

Version:

$Revision: 1.18 $

Author:

Gerd Neugebauer

See Also:

Serialized Form

serialVersionUID

protected static final long serialVersionUID

The constant serialVersionUID contains the id for serialization.

See Also:

Constant Field Values

Expandafter

public Expandafter(java.lang.String name)

Creates a new object.

Parameters:

name - the name for debugging

execute

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

Overrides:

execute in class AbstractCode

Throws:

InterpreterException

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)

expand

public void expand(Flags prefix,
                   Context context,
                   TokenSource source,
                   Typesetter typesetter)
            throws InterpreterException

Description copied from interface: ExpandableCode

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:

InterpreterException - in case of an error

See Also:

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