| 1: | <?php |
| 2: | |
| 3: | declare(strict_types=1); |
| 4: | |
| 5: | /** |
| 6: | * This file is part of the Nexus framework. |
| 7: | * |
| 8: | * (c) John Paul E. Balandan, CPA <paulbalandan@gmail.com> |
| 9: | * |
| 10: | * For the full copyright and license information, please view |
| 11: | * the LICENSE file that was distributed with this source code. |
| 12: | */ |
| 13: | |
| 14: | namespace Nexus\Result; |
| 15: | |
| 16: | /** |
| 17: | * A PHP implementation of Rust's Result enum. |
| 18: | * |
| 19: | * `Result<T, E>` is the type used for returning and propagating errors. It is |
| 20: | * an enum with the variants, `Ok(T)`, representing success and containing a |
| 21: | * value, and `Err(E)`, representing error and containing an error value. |
| 22: | * |
| 23: | * @template T |
| 24: | * @template E |
| 25: | * |
| 26: | * @see https://doc.rust-lang.org/std/result/enum.Result.html |
| 27: | */ |
| 28: | interface Result |
| 29: | { |
| 30: | /** |
| 31: | * Returns `true` if the result is `Ok`. |
| 32: | * |
| 33: | * @phpstan-assert-if-true Ok<T> $this |
| 34: | * @phpstan-assert-if-false Err<E> $this |
| 35: | */ |
| 36: | public function isOk(): bool; |
| 37: | |
| 38: | /** |
| 39: | * Returns `true` if the result is `Ok` and the value inside of it matches a predicate. |
| 40: | * |
| 41: | * @param (\Closure(T): bool) $predicate |
| 42: | */ |
| 43: | public function isOkAnd(\Closure $predicate): bool; |
| 44: | |
| 45: | /** |
| 46: | * Returns `true` if the result is `Err`. |
| 47: | * |
| 48: | * @phpstan-assert-if-true Err<E> $this |
| 49: | * @phpstan-assert-if-false Ok<T> $this |
| 50: | */ |
| 51: | public function isErr(): bool; |
| 52: | |
| 53: | /** |
| 54: | * Returns `true` if the result is `Err` and the value inside of it matches a predicate. |
| 55: | * |
| 56: | * @param (\Closure(E): bool) $predicate |
| 57: | */ |
| 58: | public function isErrAnd(\Closure $predicate): bool; |
| 59: | |
| 60: | /** |
| 61: | * Maps a `Result<T, E>` to `Result<U, E>` by applying a function to a |
| 62: | * contained `Ok` value, leaving an `Err` value untouched. |
| 63: | * |
| 64: | * @template U |
| 65: | * |
| 66: | * @param (\Closure(T): U) $predicate |
| 67: | * |
| 68: | * @return self<U, E> |
| 69: | */ |
| 70: | public function map(\Closure $predicate): self; |
| 71: | |
| 72: | /** |
| 73: | * Returns the provided default (if `Err`), or applies a function to the contained value |
| 74: | * (if `Ok`). |
| 75: | * |
| 76: | * Arguments passed to `Result::mapOr()` are eagerly evaluated; if you are passing the result |
| 77: | * of a method call, it is recommended to use `Result::mapOrElse()`, which is lazily |
| 78: | * evaluated. |
| 79: | * |
| 80: | * @template U |
| 81: | * |
| 82: | * @param U $default |
| 83: | * @param (\Closure(T): U) $predicate |
| 84: | * |
| 85: | * @return U |
| 86: | */ |
| 87: | public function mapOr(mixed $default, \Closure $predicate): mixed; |
| 88: | |
| 89: | /** |
| 90: | * Maps a `Result<T, E>` to `U` by applying fallback function `$default` to a contained |
| 91: | * `Err` value, or function `$predicate` to a contained `Ok` value. |
| 92: | * |
| 93: | * This method can be used to unpack a successful result while handling an error. |
| 94: | * |
| 95: | * @template U |
| 96: | * |
| 97: | * @param (\Closure(E): U) $default |
| 98: | * @param (\Closure(T): U) $predicate |
| 99: | * |
| 100: | * @return U |
| 101: | */ |
| 102: | public function mapOrElse(\Closure $default, \Closure $predicate): mixed; |
| 103: | |
| 104: | /** |
| 105: | * Maps a `Result<T, E>` to `Result<T, F>` by applying a function to a contained |
| 106: | * `Err` value, leaving an `Ok` value untouched. |
| 107: | * |
| 108: | * This method can be used to pass through a successful result while handling an error. |
| 109: | * |
| 110: | * @template F |
| 111: | * |
| 112: | * @param (\Closure(E): F) $predicate |
| 113: | * |
| 114: | * @return self<T, F> |
| 115: | */ |
| 116: | public function mapErr(\Closure $predicate): self; |
| 117: | |
| 118: | /** |
| 119: | * Returns the contained `Ok` value. |
| 120: | * |
| 121: | * Because this method may throw, its use is generally discouraged. Instead, prefer to |
| 122: | * use pattern matching and handle the `Err` case explicitly, or call `Result::unwrapOr()`, |
| 123: | * or `Result::unwrapOrElse()`. |
| 124: | * |
| 125: | * @return T |
| 126: | * |
| 127: | * @throws UnwrappedResultException if result is `Err` |
| 128: | */ |
| 129: | public function unwrap(): mixed; |
| 130: | |
| 131: | /** |
| 132: | * Returns the contained `Ok` value or a provided `$default`. |
| 133: | * |
| 134: | * Arguments passed to `Result::unwrapOr()` are eagerly evaluated; if you are passing |
| 135: | * the result of a method call, it is recommended to use `Result::unwrapOrElse()`, |
| 136: | * which is lazily evaluated. |
| 137: | * |
| 138: | * @template U |
| 139: | * |
| 140: | * @param U $default |
| 141: | * |
| 142: | * @return T|U |
| 143: | */ |
| 144: | public function unwrapOr(mixed $default): mixed; |
| 145: | |
| 146: | /** |
| 147: | * Returns the contained `Ok` value or computes it from a closure. |
| 148: | * |
| 149: | * @template U |
| 150: | * |
| 151: | * @param (\Closure(E): U) $op |
| 152: | * |
| 153: | * @return T|U |
| 154: | */ |
| 155: | public function unwrapOrElse(\Closure $op): mixed; |
| 156: | |
| 157: | /** |
| 158: | * Returns the contained `Err` value. |
| 159: | * |
| 160: | * Throws if the value is an `Ok`, with a custom exception message |
| 161: | * provided by the `Ok`’s value. |
| 162: | * |
| 163: | * @return E |
| 164: | * |
| 165: | * @throws UnwrappedResultException if result is `Ok` |
| 166: | */ |
| 167: | public function unwrapErr(): mixed; |
| 168: | |
| 169: | /** |
| 170: | * Returns `$res` if the result is `Ok`, otherwise returns the `Err` value of self. |
| 171: | * |
| 172: | * Arguments passed to `Result::and()` are eagerly evaluated; if you are passing the |
| 173: | * result of a method call, it is recommended to use `Result::andThen()`, which is |
| 174: | * lazily evaluated. |
| 175: | * |
| 176: | * @template U |
| 177: | * |
| 178: | * @param self<U, E> $res |
| 179: | * |
| 180: | * @return self<U, E> |
| 181: | */ |
| 182: | public function and(self $res): self; |
| 183: | |
| 184: | /** |
| 185: | * Calls `$op` if the result is `Ok`, otherwise returns the `Err` value of self. |
| 186: | * |
| 187: | * This method can be used for control flow based on `Result` values. Often used to chain |
| 188: | * fallible operations that may return `Err`. |
| 189: | * |
| 190: | * @template U |
| 191: | * |
| 192: | * @param (\Closure(T): self<U, E>) $op |
| 193: | * |
| 194: | * @return self<U, E> |
| 195: | */ |
| 196: | public function andThen(\Closure $op): self; |
| 197: | |
| 198: | /** |
| 199: | * Returns `$res` if the result is `Err`, otherwise returns the `Ok` value of self. |
| 200: | * |
| 201: | * Arguments passed to `Result::or()` are eagerly evaluated; if you are passing the |
| 202: | * result of a method call, it is recommended to use `Result::orElse()`, which is |
| 203: | * lazily evaluated. |
| 204: | * |
| 205: | * @template F |
| 206: | * |
| 207: | * @param self<T, F> $res |
| 208: | * |
| 209: | * @return self<T, F> |
| 210: | */ |
| 211: | public function or(self $res): self; |
| 212: | |
| 213: | /** |
| 214: | * Calls `$op` if the result is `Err`, otherwise returns the `Ok` value of self. |
| 215: | * |
| 216: | * This method can be used for control flow based on result values. |
| 217: | * |
| 218: | * @template F |
| 219: | * |
| 220: | * @param (\Closure(E): self<T, F>) $op |
| 221: | * |
| 222: | * @return self<T, F> |
| 223: | */ |
| 224: | public function orElse(\Closure $op): self; |
| 225: | } |
| 226: |