feat: single expression functions #17677
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This feature was proposed and declined a few years ago. Enough time has passed to propose it again, but it would be beneficial to read the corresponding threads and understand the objections. https://wiki.php.net/rfc/short-functions |
| // function buz(): int = 456; // TODO: must be the same as return 456; | ||
| // echo buz() . PHP_EOL; | ||
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| function compare(int $what, int $with): string = switch(true) { |
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I'm actually kind of shocked that a switch works here, since I thought it was all statements. I would expect match() to be much more commonly used here.
Checking switch() is fine, but please include a match() test as well, as that seems the more common use case.
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It doesn't really work. If this were a match, the value would fail to be returned, and we'd just return null. This only works because of the explicit return statements in the switch.
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Request: Give this file a better name than "2" to say what it's testing that is different from the other file, and update the test description accordingly.
| zend_ast_get_str($3), $6, NULL, $11, $8, NULL); CG(extra_fn_flags) = $9; } | ||
| backup_fn_flags function_body backup_fn_flags | ||
| { $$ = zend_ast_create_decl(ZEND_AST_FUNC_DECL, $2 | $11, $1, $4, | ||
| zend_ast_get_str($3), $6, NULL, $10, $8, NULL); CG(extra_fn_flags) = $9; } |
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This does not look correct. function foo() = 'bar'; will result in the equivalent of function foo() { 'bar'; return null; }, which doesn't have the desired effect.
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Is there a reason to develop the feature further without RFC success? |
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Generally speaking, at least some voters want to see a working implementation before they vote. Sometimes implementation details do matter (weird side effects, performance, etc.). It doesn't have the be the absolute perfectly polished PR, but at least something that works and is close to the final form. Also, I wouldn't call the limited discussion on the list so far "without success." If anything it's more positive than I got when proposing my version originally. :-) (You're welcome to borrow liberally from the code and tests there if you'd like.) |
I'd like to introduce single expression function declarations, as long as Kotlin has: https://kotlinlang.org/docs/functions.html#single-expression-functions
Example: https://pl.kotl.in/u_4w9vJmj
SEF supports expressions, but seems like statements are also supported in some limited way.
E.g.
fun statement2() = a = 2cause error.I'd support statements in PHP as well, cause there are no difference between returning
NULLor a result of expression.I'd ask for help how to implement short functions always return expression result. I think I need to create a new ast node like short declaration does and implement logic, or it's better to reuse short declaration logic?
RFC: https://wiki.php.net/rfc/single-expression-functions