PUMA
Istituto di Scienza e Tecnologie dell'Informazione     
Fantechi A., Mazzanti F. The draft formal definition of ADA. Modelling implementation dependent aspects. Internal note IEI-B4-74, 1986.
 
 
Abstract
(English)
The abstract semantics of an Ada program has to deal with several aspects of the language which are explicitly specified to be dependent on or defined by the implementation. In some cases, these aspects are actually related to some abstract properties of the supporting implementation which should be put in evidence by a formal definition. In some other cases, the aspects which are specified to be implementation dependent or implementation defined represent in effect an interaction with the external world in which the Ada program is merged; in this case, the formal definition of the language, explicit1y modelling its interaction with the external world, does not appear to be dependent on the implementation. In this case, it is the behaviour of the external system which might be partially undefined and potentially dependent on a particular implementation. In some other cases, the aspects which are specified to be implementation dependent do not affect the abstract semantics of the language, as they are related for example to the concrete implementation of some abstract data type completely specified in the RM. In the following, all these cases are further analyzed, illustrating how I/O, the predefined types, the predefined attributes, and other so-called implementation dependent aspects are modelled with respect to the above subdivision. The following is to be considered as a general rationale for the modeling of Ada implementation dependent aspects, which takes in account the full Ada definition.
Subject ADA language


Icona documento 1) Download Document PDF


Icona documento Open access Icona documento Restricted Icona documento Private

 


Per ulteriori informazioni, contattare: Librarian http://puma.isti.cnr.it

Valid HTML 4.0 Transitional