/maybe

Option & Result types for PHP

Primary LanguagePHPMIT LicenseMIT

Maybe: Option & Result for PHP

Help yourself by not returning null, false, -1 or throwing exception for everything by using Option & Result instead.

Using those makes it harder to make mistake, make it easy to do common operations on unknown returned values and can help static analysis tool detect incorrect logic in PHP code.

Installation

composer req texthtml/maybe

Documentation

Read the documentation full API description, detailed explainations and usages.

Usage

Option

TH\Maybe\Option is a type that represents an optional value: every Option is either Some and contains a value, or None, and does not.

/**
 * @param Option<float>
 */
function divide(float $numerator, float $denominator): Option {
    return match ($denomintor) {
        0.0 => Option\none(),
        _ => Option\some($numerator / $denominator)
    };
}

// The return value of the function is an option
$result = divide(2.0, 3.0);

// Pattern match to retrieve the value
if ($result instanceof Option\Some) {
    // The division was valid
    echo "Result: {$option->unwrap()}");
} else {
    // The division was invalid
    echo "Cannot divide by 0";
}

Result

TH\Maybe\Result is a type that represents either success (Ok), containing the result of an operation or failure (Err), containing the reason of the failure.

/**
 * @param Result<int,string>
 */
function parse_version(string $header): Result {
    return match ($header[0] ?? null) {
        null => Result\err("invalid header length"),
        "1" => Result\ok(1),
        "2" => Result\ok(2),
        default => Result\err("invalid version"),
    };
}

$version = parse_version("1.x");
if ($version instanceof Result\Ok) {
    echo "working with version: {$version->unwrap()}";
} else {
    echo "error parsing header: {$version->unwrapErr()}";
}
// @prints working with version: 1