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From: nhr@eng.cam.ac.uk (Neil Russell)
Newsgroups: comp.lang.eiffel
Subject: Re: Storing C pointers in Eiffel code
Message-ID: <18527@rasp.eng.cam.ac.uk>
Date: 11 Dec 90 22:10:15 GMT
References: <1039@tetrauk.UUCP> <1990Dec5.171420.22935@bony1.uucp> <1047@tetrauk.UUCP>
Sender: nhr@eng.cam.ac.uk
Organization: Cambridge University Engineering Department, UK
Lines: 17

How about using a builtin type ADDRESS (a al Modula-2).  In modula-2
the type ADDRESS is compatible with any pointer type (analogously
class type in Eiffel), and in addition to assignment, arithmetic may be
performed on values of type ADDRESS permitting the construction of
memory managers.  This latter feature may not be suitable/relevant
in the Eiffel context, where memory management (garbage collection) is
hidden from the Eiffel programmer.  Portability considerations aside,
the attraction of having a specific type (as opposed to integer or
`bits N') is clarity.

A not totally unrelated defficiency of Eiffel is the inability to
define formal enumeration types -- entities representing enumerations
of UNIQUE values must be delared as anonymous integers which makes code
a lot less clear, and of course error prone.

Neil.
E-mail: nhr@uk.ac.cam.eng