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Subject: Re: [PHP-DEV] Change default serialize precision from 100 to 17
From: nicolas.grekas+php@gmail.com (Nicolas Grekas)

> ini_set('precision', 17);

After some testings, here is what I get :

<?php

ini_set('precision', 14);
echo 0.1; // 0.1
echo 0.2; // 0.2
echo 0.3; // 0.3

ini_set('precision', 17);
echo 0.2; // 0.10000000000000001
echo 0.2; // 0.20000000000000001
echo 0.3; // 0.29999999999999999

?>

The default precision of 14 (or 12) must have been chosen to address
this overlong string representation of many simple floats ?
While I agree with you that any data loss must be forbidden, couldn't
this also break existing code ?
Would it be possible to "displays a value based on the shortest
decimal fraction that rounds correctly back to the true binary value",
like python 2.7 and 3.1 do ?
(http://docs.python.org/tutorial/floatingpoint.html)

Just my 2cts :)

Nicolas