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Issue NOT-AND-NULL-RETURN-VALUE Writeup

Forum:          Public Review

Issue: NOT-AND-NULL-RETURN-VALUE

References: Margolin's public review comment #6

Pitman's public review comment #4

Category: CHANGE

Edit history: 12 Sept 1993, Version 1 by Loosemore

Status: Proposal X3J13-MARCH-1993 passed 6-2 at the March 1993 meeting

Problem description:

Due to an editing error, the semantics of NOT and NULL have been

changed to say that they return true/false rather than T/NIL. This

change was accidentally introduced; there was no foundation for it in

any X3J13 vote.

Proposal (NOT-AND-NULL-RETURN-VALUE:X3J13-MARCH-1993):

Restore the CLtL semantics.

Rationale:

This is what users expect. It supports idioms such as

(EQ (NOT (NOT X)) 'T)

and

(DEFUN BOOLEAN-EQUAL-P (X Y) (EQ (NOT X) (NOT Y)))

Current practice:

Unknown.

Cost to implementors:

Unknown.

Cost to users:

None.

Aesthetics:

Editorial impact:

Discussion:


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