oops; meant to include Pharo in the discussion ---------- Forwarded message ---------- From: Eliot Miranda <eliot.miranda@gmail.com> Date: Wed, Aug 6, 2014 at 12:42 PM Subject: Re: [squeak-dev] Float parsed as a Fraction bug To: The general-purpose Squeak developers list < squeak-dev@lists.squeakfoundation.org> Hi Levente, On Wed, Aug 6, 2014 at 11:43 AM, Levente Uzonyi <leves@elte.hu> wrote:
On Wed, 6 Aug 2014, Eliot Miranda wrote:
Hi All,
Squeak trunk also suffers from the Float parsed as a Fraction bug:
1e-8 class Fraction 1.0e8 class Float
I'm not entirely sure about it being a bug. I've checked Squeak 3.8 (pre-SqNumberParser), and it also parsed that literal as a Fraction. If I want a Float, I can be explicit and use 1.0e-8.
IMO it very much *is* a bug. Smalltalk-80 has never supported Fraction literals. They're always written as division expressions. Fraction answers false to isLiteral. Just because it worked that way doesn't mean it was right. I suspect no one noticed. Allowing Fraction literals feels like a big change to me. I made a modified version of Fraction >> #printOn:base: which outputs the
literal format if possible. The change "fixes" the debugger (note that itw was way less broken in Squeak than in Pharo anyway). The only drawback I found is that some fractions become a bit more "complex" when printed, e.g. 3/4 => 75e-2
OK, but is this the right fix? What does everybody think? Keep the language unchanged or add Fraction literals and add another incompatibility with other dialects? If Fractions are literals - what is the semantics of 1/0 (easy, it is not a literal, but needs to be stated)? - what is [1/0.1] on: ZeroDivide do: [:ex| #error] ? Is it 10.0 or #error, i.e. is 1/0.1 10.0 or 1 / 0 followed by the Integer 1?
Levente
-- eek! Eliot
-- best, Eliot
-- best, Eliot