Hi
On 6/3/24 18:23, Derick Rethans wrote:
I would like to start an RFC discussion regarding rounding modes.
https://wiki.php.net/rfc/correctly_name_the_rounding_mode_and_make_it_an_enum
I think it would be really helpful to have a description (and examples)
for each of the rounding modes in the Enum
(https://wiki.php.net/rfc/correctly_name_the_rounding_mode_and_make_it_an_enum#proposal)
— that'd also be great for creating documentation later on.
The `RoundingMode` enum will not provide any new rounding modes, thus
the existing documentation of rounding modes applies. The corresponding
constant names have been mentioned.
Nevertheless I've just added a PHPDoc with a brief definition and
examples to each of the enum cases.
Please note: The definition is a little simplified to make it easier to
understand the differences on a conceptual level.
It assumes arbitrary precision (which floats do not provide) and it
assumes that rounding always rounds to integer values. In reality the
round() function supports a specified number of decimal digits, with
integer rounding being rounding to 0 decimal digits. An integer rounding
function can emulate rounding to a specific number of decimal digits by
multiplying the input value by 10**$digits, performing integer rounding,
and then dividing by 10**$digits (assuming arbitrary precision).
There's also a helpful table on Wikipedia:
https://en.wikipedia.org/wiki/Rounding#Comparison_of_approaches_for_rounding_to_an_integer
Hope this helps.
Best regards
Tim Düsterhus
