A PHP implementation of Rust's Result type with roughly the same API.
Version 3.x.x requires PHP 7.3+. Make sure you match the versions for this and the Option library if you use both.
composer require prewk/resultuse Prewk\Result;
use Prewk\Result\{Ok, Err};
function someApiCall(): Result {
// ...
if ($apiCallSuccesful) {
return new Ok($results);
} else {
return new Err($error);
}
}
function anotherApiCall(): Result {
// ...
if ($apiCallSuccesful) {
return new Ok($results);
} else {
return new Err($error);
}
}
// Fallback to value
$value = someApiCall()->unwrapOr(null);
// Fallback to result and throw an exception if both fail
$value = someApiCall()->orElse(function($err) {
return anotherApiCall();
})->unwrap();
// Throw custom exception on error
$value = someApiCall()->expect(new Exception("Oh noes!"));Optional global helper functions exist to simplify result object construction:
ok(); // new Prewk\Result\Ok(null);
ok($val); // new Prewk\Result\Ok($val);
err($e); // new Prewk\Result\Err($e);Add the following to your composer.json:
{
"autoload": {
"files": [
"vendor/prewk/result/helpers.php"
]
}
}If an Err containing an Exception is unwrapped, that Exception will be thrown. Otherwise a generic ResultException will be thrown.
If all results are Ok, give them to the contained callable value as arguments and put the callable's returned value in a new Ok. If any result is an Err, return the first Err.
$sum = function(int $foo, int $bar): int
{
return $foo + bar;
}
ok($sum)->apply(ok(100), ok(200), ok(300)); // Ok<600>
ok($sum)->apply(ok(100), ok(200), err(new Exception)); // Err<Exception>The with method will include the variadically added arguments in consecutive closures (map, andThen, etc). This is useful when chaining dependent ops.
ok($foo)->with($bar, $baz)
->map(function($foo, $bar, $baz) {
return $foo . $bar . $baz;
});Note that or and and will be evaluated immediately:
// This will call all three api calls regardless of successes/errors
$this
->apiCall()
->or(anotherApiCall())
->and(thirdApiCall());See andThen and orElse for lazy evaluation.
MIT & Apache 2.0