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*To*: srfi-67@xxxxxxxxxxxxxxxxx*Subject*: Re: transitivity does not imply type-checking*From*: Jens Axel Søgaard <jensaxel@xxxxxxxxxxxx>*Date*: Sun, 20 Nov 2005 14:32:22 +0100*Delivered-to*: srfi-67@xxxxxxxxxxxxxxxxx*In-reply-to*: <lyveynxyyr.fsf@xxxxxxxxxxxxxxxx>*References*: <lyhda8zy4e.fsf@xxxxxxxxxxxxxxxx> <437F6A1F.60304@xxxxxxxxxxxx> <lyzmnzy81c.fsf@xxxxxxxxxxxxxxxx> <43804A11.6050505@xxxxxxxxxxxx> <lyveynxyyr.fsf@xxxxxxxxxxxxxxxx>*User-agent*: Mozilla Thunderbird 1.0.2 (Windows/20050317)

Matthias Radestock wrote:

Jens Axel Søgaard <jensaxel@xxxxxxxxxxxx> writes:I was just saying *if* you make that interpretation, you need to type check all arguments.

Apologies for harping on about this, but my initial post contained a counter-example: an implementation of = that meets the criteria of your interpretation, yet does not type-check all args.

Sorry - I misread your post - I thought the example was meant to show, that type checking wasn't neccessary in R5RS. Your example was: (define (= x y . rest) (and (number? x) (number? y) (prim= x y) (or (null? rest) (apply my= y rest)))) Hmm - just returning #f, in error situations does indeed make it transitive. It does lead to strange behaviour. Even though (< 1 'a) => #f (> 1 'a) => #f we get that (= 1 'a) => #f . I'd prefer as many errors to be signaled as possible, but I guess that's a matter of taste. What's your view? > That is fine by me, but it is not the rationale given by the srfi > document, which instead claims that type-checking of all args is > implied > by the R5RS requirement for transitivity. The point of this thread was > to ascertain whether the latter is actually the case. It isn't. Yes - the wording could have been better. -- Jens Axel Søgaard

**Follow-Ups**:**Re: transitivity does not imply type-checking***From:*Matthias Radestock

**References**:**transitivity does not imply type-checking***From:*Matthias Radestock

**Re: transitivity does not imply type-checking***From:*Jens Axel Søgaard

**Re: transitivity does not imply type-checking***From:*Matthias Radestock

**Re: transitivity does not imply type-checking***From:*Jens Axel Søgaard

**Re: transitivity does not imply type-checking***From:*Matthias Radestock

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