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Re: [Scheme-reports] (angle -0.0-0.0i) should be -pi, but R7RS-draft-6 prohibits this

Mark H Weaver scripsit:

> There is widespread agreement in the relevant floating point standards
> (C99, C11, ISO/IEC 10967, and probably IEEE 754 although I haven't
> purchased a copy) that (angle -0.0-0.0i) = (atan -0.0 -0.0) = -pi, but
> the definition of 'angle' on page 36 of R7RS-draft-6 (section 6.2.6)
> asserts that -pi<  (angle z)<= pi for all complex 'z'.  I suggest that
> this be changed to -pi<= (angle z)<= pi.
> Another problem along the same lines: earlier on page 36, R7RS-draft-6 
> asserts that the value of "log z is defined to be the one whose 
> imaginary part lies in the range from -pi (exclusive) to pi 
> (inclusive)", and then proceeds to define the inverse trigonometric 
> functions in terms of log.  That should be changed to '-pi (inclusive)'.

These changes were adopted by the WG under no-objection procedure.

You know, you haven't stopped talking           John Cowan
since I came here. You must have been           http://www.ccil.org/~cowan
vaccinated with a phonograph needle.            cowan@x
        --Rufus T. Firefly

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