Skip to content

Commit

Permalink
refactor: add species
Browse files Browse the repository at this point in the history
  • Loading branch information
@crimx
crimx committed Jan 4, 2024
1 parent 3b0bc65 commit d368d99
Show file tree
Hide file tree
Showing 3 changed files with 56 additions and 58 deletions.
8 changes: 5 additions & 3 deletions src/option.ts
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
import type { UnwrapErr, UnwrapOk } from "./result";

import { Result } from "./result";
import { NONE, OPTION } from "./utils";
import { NONE, SPECIES, SPECIES_OPTION } from "./utils";

type Falsy = false | 0 | 0n | "" | null | undefined;
type Truthy<T> = Exclude<T, Falsy>;
Expand Down Expand Up @@ -72,7 +72,9 @@ export class Option<T = any> {
* @param maybeOption - A value that might be an `Option`
*/
public static isOption<T>(maybeOption: unknown): maybeOption is Option<T> {
return !!maybeOption && (maybeOption as Option<T>)[OPTION] === 1;
return (
!!maybeOption && (maybeOption as Option<T>)[SPECIES] === SPECIES_OPTION
);
}

/**
Expand All @@ -87,7 +89,7 @@ export class Option<T = any> {
: false;
}

private readonly [OPTION] = 1;
private readonly [SPECIES] = SPECIES_OPTION;

private readonly _value: T;

Expand Down
96 changes: 46 additions & 50 deletions src/result.ts
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
import type { UnwrapOption } from "./option";

import { Option } from "./option";
import { ERR, OK, RESULT } from "./utils";
import { SPECIES, SPECIES_RESULT } from "./utils";

export type UnwrapOk<T, Default = T> = T extends Result<infer U> ? U : Default;
export type UnwrapErr<E, Default = E> = E extends Result<infer _S, infer U>
Expand All @@ -21,15 +21,15 @@ export class Result<T = any, E = any> {
* @param value - A value of type `T`
* @returns Wrap a value into an `Result`.
*/
public static Ok = <T, E = any>(value: T): Result<T, E> =>
Object.freeze(new Result(value, ERR)) as Result<T, E>;
public static readonly Ok = <T, E = any>(value: T): Result<T, E> =>
Object.freeze(new Result<T, E>(value, true)) as Result<T, E>;

/**
* @param error - An error of type `E`
* @returns Wrap an error into an `Result`.
*/
public static Err = <E, T = any>(error: E): Result<T, E> =>
Object.freeze(new Result(OK, error)) as Result<T, E>;
public static readonly Err = <E, T = any>(error: E): Result<T, E> =>
Object.freeze(new Result<T, E>(error, false)) as Result<T, E>;

/**
* `Err` if the value is an `Error`.
Expand All @@ -51,7 +51,6 @@ export class Result<T = any, E = any> {
predicate: (source: T | E) => source is T,
thisArg?: any
): Result<T, E>;

/**
* `OK` if the value satisfies the predicate, otherwise `Err`
*
Expand Down Expand Up @@ -116,7 +115,9 @@ export class Result<T = any, E = any> {
public static isResult<T, E>(
maybeResult: unknown
): maybeResult is Result<T, E> {
return !!maybeResult && (maybeResult as Result<T>)[RESULT] === 1;
return (
!!maybeResult && (maybeResult as Result<T>)[SPECIES] === SPECIES_RESULT
);
}

/**
Expand All @@ -127,20 +128,18 @@ export class Result<T = any, E = any> {
*/
public static isSame(a: unknown, b: unknown): boolean {
return Result.isResult(a) && Result.isResult(b)
? a.isOk()
? Object.is(a._value, b._value)
: Object.is(a._error, b._error)
? Object.is(a._value, b._value)
: false;
}

private [RESULT] = 1;
private readonly [SPECIES] = SPECIES_RESULT;

private _value: T;
private _error: E;
private readonly _value: T | E;
private readonly _ok: boolean;

private constructor(value: T, error: E) {
private constructor(value: T | E, ok: boolean) {
this._value = value;
this._error = error;
this._ok = ok;
}

/**
Expand All @@ -149,39 +148,39 @@ export class Result<T = any, E = any> {
* The iterator yields one value if the result is `Ok`, otherwise none.
*/
*[Symbol.iterator]() {
if (this.isOk()) {
yield this._value;
if (this._ok) {
yield this._value as T;
}
}

/**
* @returns `true` if the `Result` is an `Ok`.
*/
public isOk(): boolean {
return this._value !== OK;
return this._ok;
}

/**
* @returns `true` if the `Result` is an `Err`.
*/
public isErr(): boolean {
return this._error !== ERR;
return !this._ok;
}

/**
* @returns `true` if the `Result` is an `Ok` and and the value inside of it matches a predicate.
* @param thisArg - If provided, it will be used as the this value for each invocation of predicate. If it is not provided, `undefined` is used instead.
*/
public isOkAnd(predicate: (value: T) => boolean, thisArg?: any): boolean {
return this.isOk() && predicate.call(thisArg, this._value);
return this._ok && predicate.call(thisArg, this._value as T);
}

/**
* @returns `true` if the `Result` is an `Err` and and the error inside of it matches a predicate.
* @param thisArg - If provided, it will be used as the this value for each invocation of predicate. If it is not provided, `undefined` is used instead.
*/
public isErrAnd(predicate: (error: E) => boolean, thisArg?: any): boolean {
return this.isErr() && predicate.call(thisArg, this._error);
return !this._ok && predicate.call(thisArg, this._value as E);
}

/**
Expand All @@ -192,14 +191,12 @@ export class Result<T = any, E = any> {
*/
public isSame(other: unknown): boolean {
return Result.isResult(other)
? this.isOk()
? Object.is(this._value, other._value)
: Object.is(this._error, other._error)
? Object.is(this._value, other._value)
: false;
}

public and<BT, BE = any>(resultB: Result<BT, BE>): Result<BT, E | BE> {
return this.isOk() ? resultB : (this as Err<E | BE>);
return this._ok ? resultB : (this as Err<E | BE>);
}

/**
Expand All @@ -212,8 +209,8 @@ export class Result<T = any, E = any> {
getResultB: (value: T) => Result<BT, BE>,
thisArg?: any
): Result<BT, BE | E> {
return this.isOk()
? getResultB.call(thisArg, this._value)
return this._ok
? getResultB.call(thisArg, this._value as T)
: (this as Err<BE | E>);
}

Expand All @@ -225,7 +222,7 @@ export class Result<T = any, E = any> {
* @param resultB - A `Result`
*/
public or<BT, BE = any>(resultB: Result<BT, BE>): Result<T | BT, E | BE> {
return this.isOk() ? this : resultB;
return this._ok ? this : resultB;
}

/**
Expand All @@ -238,15 +235,14 @@ export class Result<T = any, E = any> {
getResultB: () => Result<BT, BE>,
thisArg?: any
): Result<T | BT, E | BE> {
return this.isOk() ? this : getResultB.call(thisArg);
return this._ok ? this : getResultB.call(thisArg);
}

/**
* Converts from `Option<Option<T>>` to `Option<T>`
*/
public flatten(): Result<UnwrapOk<T>, E | UnwrapErr<E>> {
return this.isOk() &&
Result.isResult<UnwrapOk<T>, UnwrapErr<E>>(this._value)
return this._ok && Result.isResult<UnwrapOk<T>, UnwrapErr<E>>(this._value)
? this._value
: (this as Result<UnwrapOk<T>, E | UnwrapErr<E>>);
}
Expand All @@ -259,8 +255,8 @@ export class Result<T = any, E = any> {
* @returns `Err` if the `Result` is `Err`, otherwise returns `Ok(fn(value))`.
*/
public map<U>(fn: (value: T) => U, thisArg?: any): Result<U, E> {
return this.isOk()
? Result.Ok(fn.call(thisArg, this._value))
return this._ok
? Result.Ok(fn.call(thisArg, this._value as T))
: (this as Err<E>);
}

Expand All @@ -274,9 +270,9 @@ export class Result<T = any, E = any> {
* @returns `Ok` if the `Result` is `Ok`, otherwise returns `Err(fn(error))`.
*/
public mapErr<U>(fn: (error: E) => U, thisArg?: any): Result<T, U> {
return this.isErr()
? Result.Err(fn.call(thisArg, this._error))
: (this as Ok<T>);
return this._ok
? (this as Ok<T>)
: Result.Err(fn.call(thisArg, this._value as E));
}

/**
Expand All @@ -287,7 +283,7 @@ export class Result<T = any, E = any> {
* - `Ok(_)` will be mapped to `Some(Ok(_))`.
*/
public transpose(): Option<Result<UnwrapOption<T>, E>> {
return this.isOk()
return this._ok
? Option.isOption<UnwrapOption<T>>(this._value)
? this._value.map(Result.Ok)
: Option.Some(this)
Expand All @@ -298,14 +294,14 @@ export class Result<T = any, E = any> {
* Converts from `Result<T, E>` to `Option<T>` and discarding the error, if any.
*/
public ok(): Option<T> {
return this.isOk() ? Option.Some(this._value) : Option.None;
return this._ok ? Option.Some(this._value) : Option.None;
}

/**
* Converts from `Result<T, E>` to `Option<E>` and discarding the value, if any.
*/
public err(): Option<E> {
return this.isErr() ? Option.Some(this._error) : Option.None;
return this._ok ? Option.None : Option.Some(this._value);
}

/**
Expand All @@ -316,8 +312,8 @@ export class Result<T = any, E = any> {
* @param message - Optional Error message
*/
public unwrap(message = "called `Result.unwrap()` on an `Err`"): T {
if (this.isOk()) {
return this._value;
if (this._ok) {
return this._value as T;
}
throw new Error(message);
}
Expand All @@ -335,7 +331,7 @@ export class Result<T = any, E = any> {
*/
public unwrapOr<U>(defaultValue: U): T | U;
public unwrapOr(defaultValue?: T): T | undefined {
return this.isOk() ? this._value : defaultValue;
return this._ok ? (this._value as T) : defaultValue;
}

/**
Expand All @@ -344,7 +340,7 @@ export class Result<T = any, E = any> {
* @param thisArg - If provided, it will be used as the this value for each invocation of predicate. If it is not provided, `undefined` is used instead.
*/
public unwrapOrElse<U>(fn: () => U, thisArg?: any): T | U {
return this.isOk() ? this._value : fn.call(thisArg);
return this._ok ? (this._value as T) : fn.call(thisArg);
}

/**
Expand All @@ -357,10 +353,10 @@ export class Result<T = any, E = any> {
public unwrapErr(
message = "called `Result.unwrapErr()` on an `Ok` value"
): E {
if (this.isErr()) {
return this._error;
if (this._ok) {
throw new Error(message);
}
throw new Error(message);
return this._value as E;
}

/**
Expand All @@ -376,7 +372,7 @@ export class Result<T = any, E = any> {
*/
public unwrapErrOr<U>(defaultError: U): E | U;
public unwrapErrOr(defaultError?: E): E | undefined {
return this.isErr() ? this._error : defaultError;
return this._ok ? defaultError : (this._value as E);
}

/**
Expand All @@ -385,7 +381,7 @@ export class Result<T = any, E = any> {
* @param thisArg - If provided, it will be used as the this value for each invocation of predicate. If it is not provided, `undefined` is used instead.
*/
public unwrapErrOrElse<U>(fn: () => U, thisArg?: any): E | U {
return this.isErr() ? this._error : fn.call(thisArg);
return this._ok ? fn.call(thisArg) : (this._value as E);
}

/**
Expand All @@ -396,11 +392,11 @@ export class Result<T = any, E = any> {
* @returns The value returned by the provided function.
*/
public match<U>(Ok: (value: T) => U, Err: (error: E) => U): U {
return this.isOk() ? Ok(this._value) : Err(this._error);
return this._ok ? Ok(this._value as T) : Err(this._value as E);
}

public toString(): string {
return this.isOk() ? `Ok(${this._value})` : `Err(${this._error})`;
return `${this._ok ? "Ok" : "Err"}(${this._value})`;
}
}

Expand Down
10 changes: 5 additions & 5 deletions src/utils.ts
View file
Original file line number Diff line number Diff line change
@@ -1,9 +1,9 @@
/** A meaningless value */
export const NONE: any = /* @__PURE__ */ Symbol.for("$NONE$\u2009");
export const OK: any = /* @__PURE__ */ Symbol.for("$OK$\u2009");
export const ERR: any = /* @__PURE__ */ Symbol.for("$ERR$\u2009");
export const OPTION = /* @__PURE__ */ Symbol.for("$OPTION$\u2009");
export const RESULT = /* @__PURE__ */ Symbol.for("$RESULT$\u2009");
export const NONE = /* @__PURE__ */ Symbol.for("$NONE$\u2009");
export const SPECIES = /* @__PURE__ */ Symbol.for("$TSUR_SPECIES$\u2009");

export const SPECIES_OPTION = 1;
export const SPECIES_RESULT = 2;

export const positiveNumber = (index: number): boolean => index >= 0;

Expand Down

0 comments on commit d368d99

Please sign in to comment.