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Date: Thu, 22 Jan 2015 23:39:30 +0000
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References: <53F8A1FF-C809-4DDF-9C6F-6916C3E4F044@ajf.me> <CAF+90c_kkD0xb_1=W=1bt00LfbXaN+JAn=kd7=MGmiFu_dTWXg@mail.gmail.com> <3251D635-D97C-4738-B537-935A6CC21E19@ajf.me> <54C17E2B.80708@garfieldtech.com>
To: Larry Garfield <larry@garfieldtech.com>
Subject: Re: [PHP-DEV] [RFC] Combined Comparison (Spaceship) Operator
From: ajf@ajf.me (Andrea Faulds)

Hi Larry,

> On 22 Jan 2015, at 22:48, Larry Garfield <larry@garfieldtech.com> =
wrote:
>=20
> This looks potentially quite useful, especially for multi-stage =
comparisons as you note.  Mainly it would mean I don't have to remember =
which direction is positive or negative, as I can never get that right =
without looking it up. :-)

Glad you like it. I, too, sometimes have trouble remembering what =
direction it goes in.

> The examples say nothing about mixing types, though.  Eg, what would =
these return:
>=20
> return 0 <=3D> "0"
>=20
> return "" <=3D> 0
>=20
> return 1 <=3D> [1, 2, 3]
>=20
> Ignoring object property names and going by the order of the property =
definition seems like asking for trouble, too.
>=20
> There may be easy logical answers to the above given PHP's existing =
type juggling, but they should be called out explicitly in both the RFC =
and in any subsequent documentation.

The behaviour would be the same as the current <, <=3D, =3D=3D, >=3D and =
> operators. If > currently returns TRUE, then it is 1, if =3D=3D =
currently returns TRUE, then it is 0, and if < currently returns TRUE, =
then it is -1. Despite all the ridiculousness of our existing comparison =
rules, apparently <, =3D=3D and > returning TRUE are mutually exclusive, =
thank goodness.=20

I don=E2=80=99t really want to cover this behaviour in the RFC, because =
explaining it in full is a considerable effort and the rules it uses are =
not new, they are the ones PHP already uses. The behaviour for arrays is =
perhaps a little odd, but that is our existing behaviour, and I=E2=80=99d =
rather not introduce inconsistency by making <=3D> use different rules =
to the other operators.

I agree, however, that documentation for this feature should mention the =
behaviour, possibly just linking to our existing documentation on type =
juggling.

Thanks.

--
Andrea Faulds
http://ajf.me/