public function testReduceReturnsLastOk()
{
$fn = function () {
(yield Result::ok("asd"));
(yield Result::ok("foo"));
(yield Result::ok("bar"));
};
$res = Result::reduce($fn());
$this->assertInstanceOf(Ok::class, $res);
$this->assertSame("bar", $res->unwrap());
}
<?php
use Result\Result as R;
require __DIR__ . "/vendor/autoload.php";
$divide = function ($a, $b) {
if ($b === 0 || $b === 0.0) {
return R::err("division_by_zero");
}
return R::ok($a / $b);
};
$calculateSomething = function ($a, $b, $c) use($divide) {
$errMapper = function ($err) {
return "calculation_error";
};
// $x now has a value of expression ($a / $b)
// meaning Result returned from divide was already unwrapped for you
$x = (yield $divide($a, $b));
// you can also remap errors if it's needed
$x = (yield $divide($x, $c)->remapErr($errMapper));
(yield R::ok($x + 42));
};
$res = R::reduce($calculateSomething(1, 2, 3));
var_dump($res);
$res = R::reduce($calculateSomething(1, 0, 1));
var_dump($res);
$res = R::reduce($calculateSomething(1, 2, 0));
var_dump($res);
// the error was remapped, now it will be "calculation_error"
