Re: LCL type specifications

To: ymtan@larch.lcs.mit.edu, larch-interest@src.dec.com
Subject: Re: LCL type specifications
From: Patrice Chalin <chalin@cs.concordia.ca>
Date: Thu, 14 Jul 94 18:43:53 -0400
Cc: chalin@cs.concordia.ca
Delivery-Date: Thu, 14 Jul 94 15:52:18 -0700
In-Reply-To: Your message of "Wed, 13 Jul 94 16:48:43 EDT." <9407132048.AA11108@larch.lcs.mit.edu>

> An LCL spec type is local to a specification module.  It is useful if
> you don't want clients of the module to have access to it.  Spec types
> need not be implemented.  

It seems to me that there is a possibility of misinterpretation in Yang Meng's
statement

        `Spec types need not be implemented.'
                    ^^^^^^^^

(Yang Meng can correct me if I'm wrong :-).  Spec types MUST NOT be
implemented in the sense that they must not be exported by the module.  A
module can only export non spec constants, types, or functions that are
explicitly mentioned in the interface specification (at least as far as I
understand the intended semantics of LCL).

On the other hand, of course, spec types can be implemented and used privately
in any implementation of an interface specification.

Patrice

Follow-Up(s):

LCL type specifications

From: ymtan@larch.lcs.mit.edu (Yang Meng Tan)

Reference(s):

LCL type specifications

From: ymtan@larch.lcs.mit.edu (Yang Meng Tan)