PHP 8's (string) cast of a float formats with the precision ini (14
significant digits, %.14G), not the shortest round-trip form: 1/3 is
0.33333333333333, 1e14 is 1.0E+14 and 5e-324 is 4.9406564584125E-324.
phpFloatString, used for the string form of JSON floats in size, in, regex
and integer checks, printed up to 17 digits and switched to the exponent
form only from 1e15. TestPHPFloatStringMatchesPHPCast pins 27 values to
php -r output.
A 162-case truth table recorded from WinterCMS's validator (the vendored
winter/storm Factory, Laravel 9) found three divergences, all on arrays:
- in compared array elements loosely; Laravel uses array_diff, an exact
string comparison, so ["1.0"] is not in 1,2;
- not_in failed when any element was listed; Laravel's validateNotIn is
!validateIn, so an array passes unless every element is listed;
- not_in failed an array without the array rule; Laravel passes it.
validate_rules_test.go keeps the whole table (accepted, array keys,
boolean, numeric, integer, in/not_in, sizes by type, regex, dates and
comparisons, url, presence, nested and map wildcards, bail and order).
