rfc:integer-rounding

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rfc:integer-rounding [2024/03/09 06:54] – wording maberfc:integer-rounding [2024/04/02 07:07] (current) – Declined mabe
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   * Date: 2023-09-26   * Date: 2023-09-26
   * Author: Marc Bennewitz, php@mabe.berlin   * Author: Marc Bennewitz, php@mabe.berlin
-  * Status: Under Discussion+  * Status: Declined
   * First Published at: https://wiki.php.net/RFC/integer-rounding   * First Published at: https://wiki.php.net/RFC/integer-rounding
  
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 Except ''number_format'' all of these functions take a ''float|int'', do a cast to ''float'', process on floating point number only and finally return a '' float''. Except ''number_format'' all of these functions take a ''float|int'', do a cast to ''float'', process on floating point number only and finally return a '' float''.
  
-As a result of ''round'', ''ceil'' and ''floor'' you get a floating point number rounded to your needs.+As a result of ''round'', ''ceil'' and ''floor'' the resulting value will be a floating point number rounded to your needs.
  
 In most cases this is sufficient but in cases of handling integer values above 2^53 you start to end up with unexpected results due to floating point arithmetic and precision loss. In most cases this is sufficient but in cases of handling integer values above 2^53 you start to end up with unexpected results due to floating point arithmetic and precision loss.
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 ===== Proposal ===== ===== Proposal =====
  
-This RFC proposes to perform rounding on given int and return the resulting int if possible by default. +This RFC proposes to perform rounding on given int and return a rounded int value if possible by default. 
-In case of integer under-/overflow the value will be casted to a float (double) and rounded based on the floating point number as it's done currently.+In case of integer under-/overflow the value will be cast to a float (double) and rounded based on the floating point number as it's done currently.
  
 For ''ceil'', ''floor'' and ''round'' with ''precision >= 0'' this means a given int gets returned as is. For ''ceil'', ''floor'' and ''round'' with ''precision >= 0'' this means a given int gets returned as is.
 +----
 +Rounding a given float will perform rounding on floating point number directly and return float as it's done currently.
 +There will be no implicit cast to int because floats (double) can represent a much wider range of numbers than int (32 or 64 bit).
  
 +Floating point numbers on the other hand gets imprecise on representing numbers > 2^53 but passing a float to be rounded such imprecision must be known in first place already.
 +----
 An additional argument will be introduced ''bool force_float''. An additional argument will be introduced ''bool force_float''.
 In PHP 8.next this will default to ''force_float=true'' to keep current behavior but the new behavior can already be used by passing ''force_float=false''. In PHP 8.next this will default to ''force_float=true'' to keep current behavior but the new behavior can already be used by passing ''force_float=false''.
-In PHP 9.0 the default will change to ''force_float=true'' to get the new behavior by default but the previous behavior can be forced with ''force_float=true''.+In PHP 9.0 the default will change to ''force_float=false'' to get the new behavior by default but the previous behavior can be forced with ''force_float=true''.
  
  
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 The ''int''-type is compatible to ''float'', returning an int instead of a float will still be a number accepted for type-hints of ''int'', ''float'', ''int|float'' or ''mixed'' with strict_types enabled. The ''int''-type is compatible to ''float'', returning an int instead of a float will still be a number accepted for type-hints of ''int'', ''float'', ''int|float'' or ''mixed'' with strict_types enabled.
  
-As a result PHP will behave more precise on rounding integer values.+As a result PHP will behave more precisely on rounding integer values.
  
  
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 var_dump(round(987654321098765432, precision: -3)); var_dump(round(987654321098765432, precision: -3));
 var_dump(round(987654321098765432, precision: -4)); // integer overflow var_dump(round(987654321098765432, precision: -4)); // integer overflow
 +var_dump(round(10000000000000055296)); // input is float
 var_dump(takeFloat(round(987654321098765432, precision: -3))); var_dump(takeFloat(round(987654321098765432, precision: -3)));
 var_dump(returnFloat(round(987654321098765432, precision: -3))); var_dump(returnFloat(round(987654321098765432, precision: -3)));
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 var_dump(round(987654321098765432, precision: -3, force_float=true)); var_dump(round(987654321098765432, precision: -3, force_float=true));
 var_dump(round(987654321098765432, precision: -4, force_float=true)); // integer overflow var_dump(round(987654321098765432, precision: -4, force_float=true)); // integer overflow
 +var_dump(round(10000000000000055296, force_float=true)); // input is float
 var_dump(takeFloat(round(987654321098765432, precision: -3, force_float=true))); var_dump(takeFloat(round(987654321098765432, precision: -3, force_float=true)));
 var_dump(returnFloat(round(987654321098765432, precision: -3, force_float=true))); var_dump(returnFloat(round(987654321098765432, precision: -3, force_float=true)));
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 var_dump(round(987654321098765432, precision: -3, force_float=false)); var_dump(round(987654321098765432, precision: -3, force_float=false));
 var_dump(round(987654321098765432, precision: -4, force_float=false)); // integer overflow var_dump(round(987654321098765432, precision: -4, force_float=false)); // integer overflow
 +var_dump(round(10000000000000055296, force_float=false)); // input is float
 var_dump(takeFloat(round(987654321098765432, precision: -3, force_float=false))); var_dump(takeFloat(round(987654321098765432, precision: -3, force_float=false)));
 var_dump(returnFloat(round(987654321098765432, precision: -3, force_float=false))); var_dump(returnFloat(round(987654321098765432, precision: -3, force_float=false)));
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 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.8765432109877E+17) float(9.8765432109877E+17)
 +float(1.0000000000000055E+19)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
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 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.8765432109877E+17) float(9.8765432109877E+17)
 +float(1.0000000000000055E+19)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
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 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.8765432109877E+17) float(9.8765432109877E+17)
 +float(1.0000000000000055E+19)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
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 int(987654321098765000) int(987654321098765000)
 float(9.8765432109877E+17) float(9.8765432109877E+17)
 +float(1.0000000000000055E+19)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
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 int(987654321098765000) int(987654321098765000)
 float(9.8765432109877E+17) float(9.8765432109877E+17)
 +float(1.0000000000000055E+19)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
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 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.8765432109877E+17) float(9.8765432109877E+17)
 +float(1.0000000000000055E+19)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
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 int(987654321098765000) int(987654321098765000)
 float(9.8765432109877E+17) float(9.8765432109877E+17)
 +float(1.0000000000000055E+19)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
 float(9.87654321098766E+17) float(9.87654321098766E+17)
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 ===== Unaffected PHP Functionality ===== ===== Unaffected PHP Functionality =====
-Rounding floating point numbers will not be effected in any way.+Rounding floating point numbers will not be affected in any way.
  
 ===== Future Scope ===== ===== Future Scope =====
-After PHP 9 it can be considered to deprecate and remove the `force_float` argument again but due to very long future this is not part of this RFC.+After PHP 9 it can be considered to deprecate and remove the ''force_float'' argument again but due to very long future this is not part of this RFC.
  
  
-===== Proposed Voting Choices ===== +===== Proposed Voting Choices =====  
-One primary vote (requires 2/3 majority): Round on int and return int? +As per the voting RFC a yes/no vote with a 2/3 majority is needed for this proposal to be accepted. 
 +Voting started on 2024-03-17 and will end on 2024-04-02 00:00 GMT. 
 +<doodle title="Rounding Integers as int" auth="Marc Bennewitz" voteType="single" closed="false" closeon="2024-04-02T00:00:00Z"> 
 +   * Yes 
 +   * No 
 +</doodle>
  
 ===== Patches and Tests ===== ===== Patches and Tests =====
rfc/integer-rounding.1709967294.txt.gz · Last modified: 2024/03/09 06:54 by mabe

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