Package Exports
- derive-rust
Readme
derive-rust
Rust-like utils for JavaScript. Start using match pattern, enums with generics and other features similarly to the Rust programming language.
Option<T>
const a: Option<string> = Some("hello");
const b: Option<string> = None();
const c = None<string>();
Result<T, E>
const fooOk: Result<{result: boolean}, {}> = Ok({result: true});
const fooErr: Result<{result: boolean}, {}> = Err({});
Match
You can use match function with primitive and object data. Primitive and Objects implemented by Sized<T> can be used for "refutable" pattern
const s1 = match(Some("bar"), (v) => [ // v = Some("bar")
[Some("baz"), () => "baz"],
[None<string>(), () => "none"]
], (v, s) => ""); // v = Some("bar"), s = "bar"
console.log(s1) // ""
const s2 = match(Some("bar"), (v) => [
[Some("baz"), Some("bar"), () => "baz or bar"], // arm with more than one value
[None<string>(), () => "none"]
], (_, s) => s);
console.log(s2) // "baz or bar"
const s3 = match(Some("bar"), (v) => [
(bar) => [Some("baz"), Some(bar), () => "baz or " + bar], // pattern is used by wrapping in functions
[None<string>(), () => "none"]
], (_, s) => s);
console.log(s3) // "baz or bar"
const val = match(9, () => [
[3, () => Some(3)],
[0, () => None()],
v => [v, () => Some(v + 1)] // pattern sample with primitives
], () => None())
console.log(val.unwrap()) // 10
Don't compare functions
cmp(() => {}, () => {}) // 0. Zero means ignoring truthy/falsy case
// So
const o1 = {
a: 1,
barFn() {}
}
const o2 = {
a: 1,
fooFn() {}
}
cmp(o1, o2) // 1 - means true
eq(o1, o2) // true. It's just wrapper to cmp(o1, o2) === 1
// But their types are different
partialEq(o1, o2) // false. As it's generic wrapper to eqType()
My approach of creating enums with generics
class MyEnum<T = string> implements Sized<T> {
$ref: [T] = [MyEnum.name] as [T];
variant: [string | T] = [""]; // must be public for cmp() function
#variant(value: T | Function | string): MyEnum<T> {
setNoncallableRef(this, value) as MyEnum<T> // or this.$ref[0] = value;
this.variant = [fn.name]; // this value additionally guarantees that the object is unique
Object.freeze(this);
return this;
}
Foo() {
return this.variant(this.Foo);
}
Bar() {
return this.variant("baz");
}
}
const result = match(new MyEnum().Bar(), () => [
(v) => [new MyEnum().Foo(), () => v],
(v) => [new MyEnum().Bar(), () => v]
], () => "");
console.log(result) // "Bar"
Other features
type Self<S, T = void> = (self: S) => T;
// Create instances similarly to Rust
constructor(impl: (self: Class) => TypeYouWant) { impl(this) }
// or
constructor(self: Self<Class, TypeYouWant>) { self(this) } // the same
// Ranges
// 1..10
range(1, 10) // [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
// 1..=10
rangeInc(1, 10) // [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
// 'v'..='x'
rangeCharsInc('v', 'x', "stuvwxyz") // [ 'v', 'w', 'x' ]
// It works in the opposite way
range(5, -5) // [ 5, 4, 3, 2, 1, 0, -1, -2, -3, -4 ]
rangeInc(5, -5) // [ 5, 4, 3, 2, 1, 0, -1, -2, -3, -4, -5 ]
// For reveresed result with strings you need to use rangeCharsRev() and rangeCharsRevInc() though
rangeCharsRev('b', 'f', "abcdefghI") // [ 'f', 'e', 'd', 'c' ]
// Channels
function syncChannel<T>(): [SyncSender<T>, SyncReceiver<T>];
const [tx,rx] = syncChannel();
tx.send(1) // returns Result<{}, SenderError> to check if valid value has been sent
tx.send(2)
rx.recv() // returns Option<T>. In this case Some(1)
// Async channel
function channel<T>(): [Sender<T>, Receiver<T>];
const [tx, rx] = channel() // Saves the order of Promises resolving them through Result
tx.send(async () => {}) // void
rx.recv() // Promise<Result<T, ReceiverError<E>>>
Declarations
class Option<T> implements Sized<T> {
#private;
$ref: [T];
$option: [string, T];
some(value: T): Option<T>;
none(): Option<T>;
unwrap(): T;
expect(message: string): T;
unwrapOr(value: T): T;
isNone(): boolean;
isSome(): boolean;
intoResult<E>(error: E): Result<T, E>;
static from<T>(value: T): Option<T>;
static None<T = unknown>(): Option<T>;
static Some<T>(value: T): Option<T>;
}
class Result<T, E> implements Sized<T | E> {
#private;
$ref: [T | E];
$result: [string, T | E];
ok(value: T): Result<T, E>;
err(value: E): Result<T, E>;
isOk(): boolean;
isErr(): boolean;
expect(message: string): T;
unwrap(): T;
unwrapOr(value: T): T;
unwrapErr(): E;
intoOption(): Option<T>;
static from<T, E>(value: T | E): Result<T, E>;
static Ok<T, E>(value: T): Result<T, E>;
static Err<E, T>(value: E): Result<T, E>;
}
match<V, T>(value: V, matchArms: (value: V) => Array<MatchArm<V, T> | MatchArmFn<V, T>>, defaultMatchArm: (value: V, p: Extract<V>) => T): T;
ifLet<V>(p: (p: Extract<V>) => V, value: V, ifExpr: (v: Extract<V>) => void, elseExpr?: (v: Extract<V>) => void): void;
interface Sized<T = null> {
readonly $ref: [T];
}
type Self<S, T = void> = (self: S) => T;
function eqType(lhs: any, rhs: any): boolean;
function cmp<T>(lhs: T, rhs: T): 1 | -1 | 0;
function orderKeys(keys: string[], targetKeys: string[]): string[];
function partialEq<T>(lhs: T, rhs: T): boolean;
function eq<T>(lhs: T, rhs: T): boolean;
function ref<T, R>(self: Sized<R>, fn: (r: R) => T): T;
function panic(reason: string): never;
function ex<T, V>(fn: (value: V) => T, value?: V): T; // any expression just like (function(value) {})(value) . Parameter not required
function dex<I, O, V>(input: (value: V) => I, output: (value: ReturnType<typeof input>) => O, value?: V): O; // double expression
function getRef<T>(s: Sized<T>): T;
function setNoncallableRef<T>(self: Sized<T>, value: T): Sized<T>;
function setRef<T>(self: Sized<T>, value: T): Sized<T>;
function range(start: number, end: number): number[];
function rangeInc(start: number, end: number): number[];
function rangeChars(start: string, end: string, str: string): string[];
function rangeCharsInc(start: string, end: string, str: string): string[];
function rangeCharsRev(start: string, end: string, str: string): string[];
function rangeCharsRevInc(start: string, end: string, str: string): string[];
function clone<T>(value: T): T;
function syncChannel<T>(): [SyncSender<T>, SyncReceiver<T>];
function channel<T>(): [Sender<T>, Receiver<T>];