more precise preg_match types

[staabm]

Feature request

while implementing the first iteration of preg_match array-shape inference, I got a few ideas on how the type inference could be improved.

leaving it here as a feature request, so its not forgotten

https://phpstan.org/r/1e3506dd-78dc-4bbe-9c9e-2a5a2928fcfc

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[ondrejmirtes]

First thing we should is to cover preg_match_all and maybe others as well.

[phpstan-bot]

@staabm After the latest push in 1.12.x, PHPStan now reports different result with your code snippet:

@@ @@
-10: Expected type array{string, '£'|'€'}, actual: array<string>
-13: Expected type array{string, numeric-string}, actual: array<string>
-16: Expected type array{string, non-empty-string}, actual: array<string>
-19: Expected type array{string, non-empty-string}, actual: array<string>
-22: Expected type array{string, non-falsey-string}, actual: array<string>
+10: Expected type array{string, '£'|'€'}, actual: array{string, non-empty-string}
+22: Expected type array{string, non-falsey-string}, actual: array{string, non-empty-string}

Full report

Line	Error
10	`Expected type array{string, '£'
22	Expected type array{string, non-falsey-string}, actual: array{string, non-empty-string}

[phpstan-bot]

@staabm After the latest push in 1.12.x, PHPStan now reports different result with your code snippet:

@@ @@
-10: Expected type array{string, '£'|'€'}, actual: array<string>
-13: Expected type array{string, numeric-string}, actual: array<string>
-16: Expected type array{string, non-empty-string}, actual: array<string>
-19: Expected type array{string, non-empty-string}, actual: array<string>
-22: Expected type array{string, non-falsey-string}, actual: array<string>
+10: Expected type array{string, '£'|'€'}, actual: array{string, non-empty-string}
+22: Expected type array{string, non-falsey-string}, actual: array{string, non-falsy-string}

Full report

Line	Error
10	`Expected type array{string, '£'
22	Expected type array{string, non-falsey-string}, actual: array{string, non-falsy-string}