Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:112476
To: internals@lists.php.net
References: <d1c4689e-9120-4e90-837c-a1b3eac63cd6@www.fastmail.com>
 <DA260CE1-8523-4737-A5CE-052160846E79@newclarity.net>
Message-ID: <1150805a-44b0-af7e-d54b-6082fd23a63e@gmail.com>
Date: Wed, 9 Dec 2020 19:06:29 +0000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.5.1
MIME-Version: 1.0
In-Reply-To: <DA260CE1-8523-4737-A5CE-052160846E79@newclarity.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-GB
Subject: Re: [PHP-DEV] [RFC] Enumerations
From: rowan.collins@gmail.com (Rowan Tommins)

On 09/12/2020 18:47, Mike Schinkel wrote:
> 1. Will enum methods be idempotent?
>
> If not, shouldn't they be?


Can you clarify what you mean here? The only meaningful question I can 
think of is "can they change the object's state?" That's mostly answered 
in the RFC, most notably by specifying that enums may not have instance 
properties, to avoid them having any state to change.

Unless I'm missing something, trying to define "idempotence" or "pure 
functions" any more strictly than that would surely be a massive project 
in itself - for a start, you'd need a whitelist of all built-in 
operations which were side-effect free (i.e. no file writes, 
configuration changes, output, etc, etc).

Regards,

-- 
Rowan Tommins (né Collins)
[IMSoP]