Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:123043
Feedback-ID: id5114917:Fastmail
User-Agent: Cyrus-JMAP/3.11.0-alpha0-368-gc733b1d8df-fm-20240402.001-gc733b1d8
Precedence: bulk
MIME-Version: 1.0
Message-ID: <b41a5f80-5663-439b-942a-1d362116fe6e@app.fastmail.com>
In-Reply-To: 
 <CAL0xaBHW8wdPu4qsnoXwzmensO5Yj=0HQS0VLknFcSonYcci=g@mail.gmail.com>
References: <40553F28-2EC2-475A-BD8E-1D6517AA2A51@rwec.co.uk>
 <2B518F62-B774-45C9-82A2-EF6653AAE34E@sakiot.com>
 <A703D145-1A10-4C7E-9E0C-1F0BEF94CF99@rwec.co.uk>
 <F36A5C9B-7F3E-4EB7-A254-2ADB47AB6AE0@sakiot.com>
 <CAL0xaBEQdWX735rE-EoxEr=44VTX5ud=XOvxn_g1Y28V2fugFg@mail.gmail.com>
 <57c268e9be57edad86155c461b0fd181@gliadin.co.uk>
 <CAL0xaBHW8wdPu4qsnoXwzmensO5Yj=0HQS0VLknFcSonYcci=g@mail.gmail.com>
Date: Mon, 08 Apr 2024 14:38:55 +0100
To: internals@lists.php.net
Subject: Re: [PHP-DEV] Native decimal scalar support and object types in BcMath - do we
 want both?
Content-Type: multipart/alternative;
 boundary=a9238298cfc54d15a24a2441758ea4a5
From: imsop.php@rwec.co.uk ("Rowan Tommins [IMSoP]")

--a9238298cfc54d15a24a2441758ea4a5
Content-Type: text/plain

On Mon, 8 Apr 2024, at 13:42, Arvids Godjuks wrote:
> The ini setting I was considering would function similarly to what it does for floats right now - I assume it changes the exponent, thereby increasing their precision but reducing the integer range they can cover.

If you're thinking of the "precision" setting, it doesn't do anything nearly that clever; it's purely about how many decimal digits should be *displayed* when converting a binary float value to a decimal string. In recent versions og PHP, it has a "-1" setting that automatically does the right thing in most cases. https://www.php.net/manual/en/ini.core.php#ini.precision

The other way around - parsing a string to a float, including when compiling source code - has a lot of different compile-time options, presumably to optimise on different platforms; but no user options at all: https://github.com/php/php-src/blob/master/Zend/zend_strtod.c

Regards,
-- 
Rowan Tommins
[IMSoP]
--a9238298cfc54d15a24a2441758ea4a5
Content-Type: text/html
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE html><html><head><title></title><style type=3D"text/css">p.Mso=
Normal,p.MsoNoSpacing{margin:0}</style></head><body><div>On Mon, 8 Apr 2=
024, at 13:42, Arvids Godjuks wrote:<br></div><blockquote type=3D"cite" =
id=3D"qt" style=3D""><div dir=3D"ltr"><div dir=3D"ltr">The ini setting I=
 was considering would function similarly to what it does for floats rig=
ht now - I assume it changes the exponent, thereby increasing their prec=
ision but reducing the integer range they can cover.<br></div></div></bl=
ockquote><div><br></div><div>If you're thinking of the "precision" setti=
ng, it doesn't do anything nearly that clever; it's purely about how man=
y decimal digits should be *displayed* when converting a binary float va=
lue to a decimal string. In recent versions og PHP, it has a "-1" settin=
g that automatically does the right thing in most cases. <a href=3D"http=
s://www.php.net/manual/en/ini.core.php#ini.precision">https://www.php.ne=
t/manual/en/ini.core.php#ini.precision</a><br></div><div><br></div><div>=
The other way around - parsing a string to a float, including when compi=
ling source code - has a lot of different compile-time options, presumab=
ly to optimise on different platforms; but no user options at all: <a hr=
ef=3D"https://github.com/php/php-src/blob/master/Zend/zend_strtod.c">htt=
ps://github.com/php/php-src/blob/master/Zend/zend_strtod.c</a><br></div>=
<div><br></div><div>Regards,<br></div><div>-- <br>Rowan Tommins</div><di=
v>[IMSoP]<br></div></body></html>
--a9238298cfc54d15a24a2441758ea4a5--