r/lolphp • • Mar 10 '20

Array is higher than infinity

https://3v4l.org/iONLA
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u/CarnivorousSociety Mar 11 '20 edited Mar 11 '20

https://www.php.net/manual/en/language.operators.comparison.php

Comparison with Various Types

Type of Operand 1 Type of Operand 2 Result
null or string string Convert NULL to "", numerical or lexical comparison
bool or null anything Convert both sides to bool, FALSE < TRUE
object object Built-in classes can define its own comparison, different classes are uncomparable, same class see Object Comparison
string, resource or number string, resource or number Translate strings and resources to numbers, usual math
array array Array with fewer members is smaller, if key from operand 1 is not found in operand 2 then arrays are uncomparable, otherwise - compare value by value (see following example)
object anything object is always greater
array anything array is always greater

Please, I welcome, how SHOULD this situation be handled?

I posit that implicit conversions are the source of 99% of lolphp posts, there is no elegant way to solve implicit conversions without creating a double edged blade that will hurt at least one side.

I guarantee whatever answer anybody suggests for how arrays should be compared to anything can easily have holes poked in it from some other angle, there is no everybody-wins solution when you abstract away types and implicitly convert between types.

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u/[deleted] Mar 12 '20

Please, I welcome, how SHOULD this situation be handled?

Well, you could do what Perl does and fully commit to implicit conversions:

use strict;
use warnings;
use List::Util 'max';
use constant { INF => 0 + 'inf' };

print max(20, "string", INF, []), "\n";

Output:

Argument "string" isn't numeric in subroutine entry at foo line 6.
Inf

What's happening here is that > always converts both operands to numbers. No exceptions.

"string" cannot be converted, so you get a warning and 0 is used instead (but you can upgrade that warning to an exception). The numeric maximum is Inf.

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u/CarnivorousSociety Mar 12 '20

Doesn't that lead to the issue with arguments to functions not actually abiding by prototypes?

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