Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:83150
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain developersdesk.com designates 204.228.229.4 as permitted sender)
Message-ID: <54E58F06.1040707@developersdesk.com>
Date: Thu, 19 Feb 2015 00:21:42 -0700
User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Thunderbird/31.4.0
MIME-Version: 1.0
To: internals@lists.php.net
References: <54E5456E.4020103@gmx.de> <54E54E1E.1010906@lerdorf.com>
In-Reply-To: <54E54E1E.1010906@lerdorf.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Subject: Re: [PHP-DEV] Digit separators for numeric literals
From: vchkpw@developersdesk.com (Rick Widmer)

On 2/18/2015 7:44 PM, Rasmus Lerdorf wrote:
> On 02/18/2015 06:07 PM, Christoph Becker wrote:
>> Hi internals!
>>
>> A while ago a question was asked on the php-general mailing list with
>> regard to digit seperators in numeric literals[1].
>>
>> IMHO it might be a useful enhancement to allow such digit separators for
>> numeric (integer and float) literals in PHP for better readability;
>> several other languages already support them (such as Java, Perl, Ruby,
>> C#, Eiffel and C++14).
>>
>> Before attempting to draft a respective RFC, I'd like to get some
>> feedback, whether this is generally considered to be useful, which
>> character would be preferred (most other languages seem to allow the
>> underscore, but an apostroph or maybe some other character might be
>> reasonable as well), and which restrictions should be applied (e.g.
>> arbitrary use of the separator, group thousands only, etc.)
>>
>> I'm looking forward to hear your opinion.  Thanks in advance.
>>
>> [1] <http://marc.info/?l=php-general&m=142143581810951&w=2>
>
> I think it will be difficult to find a separator character that doesn't
> make a mess of the grammar.
>
>    my_func(1,999,999) obviously doesn't work
>    my_func(1'999'999) as per C++14 clashes with our single-quoted strings
>    my_func(1_999_999) like in ADA might work
>
> but _999_ would need to work as well and _ is a valid char in a constant
> so you can have a constant named _999_.
>
>    - nope
>    # nope
>    @ nope
>    ~ nope
>    ! nope
>    % nope
>    ^ nope
>
> We went through this for the namespace char, and there simply isn't a
> typable single character left to use for something like this. _ is the
> closest but it would require some changes and BC breaks which I am not
> sure is worth for what appears to me to be a not-so critical feature.
>
> Now if we went into Unicode territory, we could do it. eg.
>
>    my_func(1 999 999) U+1680 (although it looks too much like a -)
>    my_func(1 999 999) U+205F (mathematical space)
>    my_func(1٬999٬999) U+066C (Arabic thousands separator)
>    my_func(1·999·999) U+00B7 (middle dot)
>
> The last one looks best to me, but we'd need a team of people working in
> shifts to answer the, "How do I type this?" question.
>
> -Rasmus

how about:

my_func( '1,000.04' );   //if you want to use separators there.


Rick.  Who is firmly in the camp that considers type juggling an 
essential feature of PHP.