Re: [Scheme-reports] strange language in spec of `and' and `or'

[Alex Shinn <alexshinn@x>]

On Thu, May 19, 2011 at 8:55 AM, Andy Wingo <wingo@x> wrote:
> Section 4.2.1, p. 11, in the spec of `and':
>
>  "The TEST expressions are evaluated from left to right, and the value
>  of the first expression that evaluates to a false value (see section
>  6.3.1) is returned.  Any remaining expressions are not evaluated.  If
>  all the expressions evaluate to true values, the value of the last
>  expression is returned..."
>
> Why these weasel words?  Is this to somehow permit implementations with
> more than one false value to return a false value from `and' which is
> not #f ?

Good point, that's possibly wording left over from
R4RS, where #f and '() were not necessarily distinct.

#f and '() could be distinct and yet there could be
other false values (as in Guile, no?), but I'm not
sure if we need to word the standard to accomodate
such extensions.

-- 
Alex

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