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Re: Equality predicates, signed zeroes, R5RS and R6RS
From: |
Mike Gran |
Subject: |
Re: Equality predicates, signed zeroes, R5RS and R6RS |
Date: |
Mon, 31 Jan 2011 15:13:10 -0800 (PST) |
> From:Mark H Weaver <address@hidden>
> To:Mike Gran <address@hidden>
> Cc:"address@hidden" <address@hidden>
> Sent:Monday, January 31, 2011 2:42 PM
> Subject:Re: Equality predicates, signed zeroes, R5RS and R6RS
>
> Mike Gran <address@hidden> writes:
> > As an aside, as of a couple of months ago, it was possible to create
> > the following seven versions of zero in Guile using the default reader.
> >
> > 0, ±0.0, ±0.0±0.0i
>
> Really? I don't understand how this could have happened. mem2complex
> uses scm_make_rectangular to create complex numbers, and
> scm_make_rectangular calls scm_c_make_rectangular, which creates a real
> if the imaginary part is zero.
Sorry, I was completely wrong with that. I was looking at the output for
few different Schemes, and I got confused.
As you say, Guile 2.0 only gets you, 0 and ±0.0.
Sorry for the noise.
-Mike