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Re: CLOS vs. subtypes of FLOAT
- To: Masinter.pa@Xerox.COM
- Subject: Re: CLOS vs. subtypes of FLOAT
- From: Pavel.pa@Xerox.COM
- Date: Thu, 21 May 87 12:20:50 PDT
- Cc: Common-Lisp-Object-System@SAIL.Stanford.Edu
- In-reply-to: "Masinter's message of 21 May 87 12:07 PDT"
Date: 21 May 87 12:07 PDT
You omitted the possibility where all the classes
exist in all implementations, but that some of the
classes might be empty (have no instances) in some
In putting together the proposals, I had two (unfortunately unstated) design criteria:
1) Discrimination on the subtypes of FLOAT should be allowed
2) Discriminations that cannot work in a given implementation
(due to collapsing together some of the subtypes) should signal
an error so that the user doesn't lose quietly.
Proposal NONE loses on the first criterion and your proposal violates the second.