package org.aopalliance.reflect;

An abstract program unit.
Any structural unit of a base program (class, member,
...). Units exclude the code.
When referencing a program unit, the client can retrieve unit locators using getLocator() or more specific methods. This locators shall be used conjointly whith an Instrumentor implementation in order to perform aspetual transformations of the program (e.g. type merging, parameters adding,...). 
Program units also supports metadatas, i.e. the ability to add
extra information on the base program so that the client can
extends its meaning very easily.
See Also:
Instrumentor
UnitLocator
Class
Method
Field/**
 * An abstract program unit.
 *
 * <p>Any structural unit of a base program (class, member,
 * ...). Units exclude the code.
 *
 * <p>When referencing a program unit, the client can retrieve unit
 * locators using {@link #getLocator()} or more specific methods. This
 * locators shall be used conjointly whith an {@link
 * org.aopalliance.instrument.Instrumentor} implementation in order to
 * perform aspetual transformations of the program (e.g. type merging,
 * parameters adding,...).
 *
 * <p>Program units also supports metadatas, i.e. the ability to add
 * extra information on the base program so that the client can
 * extends its meaning very easily.
 *
 * @see org.aopalliance.instrument.Instrumentor
 * @see UnitLocator
 * @see Class
 * @see Method
 * @see Field */

public interface ProgramUnit {

   
Returns the locator that corresponds to this unit.
/**
    * Returns the locator that corresponds to this unit.
    */
   UnitLocator getLocator();

   
Returns the metadata that is associated to this unit from its
key. /**
    * Returns the metadata that is associated to this unit from its
    * key. */
   Metadata getMetadata(Object key);

   
Returns all the metadatas that are associated to the current
unit. /**
    * Returns all the metadatas that are associated to the current
    * unit. */
   Metadata[] getMetadatas();
   
   
Associates a metadata to the current unit.
If a metadata already exists with the same key, then its
value is replaced by the newly given one. /**
    * Associates a metadata to the current unit.
    *
    * <p>If a metadata already exists with the same key, then its
    * value is replaced by the newly given one. */
   void addMetadata(Metadata metadata);

   
Removes a metadata from its key.
If none metadata having the given key exists, then this method
has no effect. /**
    * Removes a metadata from its key.
    *
    * <p>If none metadata having the given key exists, then this method
    * has no effect. */
   void removeMetadata(Object key);
}