On Mon, Mar 31, 2025, at 5:03 PM, Niels Dossche wrote: > Hi internals! > > I'm excited to share what I've been working on! > I had an epiphany. I realized what we truly need to revolutionize PHP: > a new operator. > > Hear me out. > We live in an imperfect world, and we often approximate data, but > neither `==` nor `===` are ideal comparison operators to deal with > these kinds of data. > > Introducing: the "approximately equal" (or "approx-equal") operator > `~=` (to immitate the maths symbol ≃). > This combines the power of type coercion with approximating equality. > Who cares if things are actually equal, close enough amirite? > > First of all, if `$a == $b` holds, then `$a ~= $b` obviously. > The true power lies where the data is not exactly the same, but "close > enough"! > > Here are some examples: > > We all had situations where we wanted to compare two floating point > numbers and it turns out that due to the non-exact representation, > seemingly-equal numbers don't match! Gone are those days because the > `~=` operator nicely rounds the numbers for you before comparing them. > This also means that the "Fundamental Theorem of Engineering" now holds! > i.e. 2.7 ~= 3 and 3.14 ~= 3. Of course also 2.7 ~= 3.14. But this is > false obviously: 2 ~= 1. > > Ever had trouble with users mistyping something? Say no more! > "This is a tpyo" ~= "This is a typo". It's typo-resistant! > However, if the strings are too different, then they're not > approx-equal. > For example: "vanilla" ~= "strawberry" gives false. > How does this work? > * The strings are equal if their levenshtein ratio is <= 50%, so it's > adaptive to the length. > * If the ratio is > 50%, then the shortest string comes first in the > comparison, such that if we ever get a `~<` operator, then "vanilla" ~< > "strawberry". > > There is of course a PoC implementation available at: > https://github.com/php/php-src/pull/18214 > You can see more examples on GitHub in the tests, here is a copy: > ```php > // Number compares > var_dump(2 ~= 1); // false > var_dump(1.4 ~= 1); // true > var_dump(-1.4 ~= -1); // true > var_dump(-1.5 ~= -1.8); // true > var_dump(random_int(1, 1) ~= 1.1); // true > > // Array compares (just compares the lengths) > var_dump([1, 2, 3] ~= [2, 3, 4]); // true > var_dump([1, 2, 3] ~= [2, 3, 4, 5]); // false > > // String / string compares > var_dump("This is a tpyo" ~= "This is a typo"); // true > var_dump("something" ~= "different"); // false > var_dump("Wtf bro" ~= "Wtf sis"); // true > > // String / different type compares > var_dump(-1.5 ~= "-1.a"); // true > var_dump(-1.5 ~= "-1.aaaaaaa"); // false > var_dump(NULL ~= "blablabla"); // false > ``` > > Note that this does not support all possible Opcache optimizations > _yet_, nor does it support the JIT yet. > However, there are no real blockers to add support for that. > > I look forward to hearing you! > > Have a nice first day of the month ;) > Kind regards > Niels
Naturally, the degree of closeness for strings or for floats should be controlled by an ini setting. Maximum flexibility! --Larry Garfield
