Lucifier129

type Result<T> = { ok: true; value: T } | { ok: false; error: string };
const Ok = <T>(value: T): Result<T> => ({ ok: true, value });
const Fail = (error: string): Result<any> => ({ ok: false, error });

class Accessor<S, T> {
  constructor(
    public readonly get: (s: S) => Result<T>,
    public readonly set: (t: T, s: S) => Result<S>
  ) { }

Lucifier129

type Result<T> = { ok: true; value: T } | { ok: false; error: string };
const Ok = <T>(value: T): Result<T> => ({ ok: true, value });
const Fail = (error: string): Result<any> => ({ ok: false, error });

class Accessor<S, T> {
  constructor(
    public readonly get: (s: S) => Result<T>,
    public readonly set: (t: T, s: S) => Result<S>
  ) { }

Lucifier129

type PrimitiveData = string | number | boolean | null

type ListData = LensData[]

type ObjectData = {
  [key: string]: LensData
}

type LensData = PrimitiveData | ListData | ObjectData

Lucifier129

function pipe<A, B>(a: A, f: (a: A) => B): B;
function pipe<A, B, C>(a: A, f: (a: A) => B, g: (b: B) => C): C;
function pipe<A, B, C, D>(
  a: A,
  f: (a: A) => B,
  g: (b: B) => C,
  h: (c: C) => D
): D;
function pipe<A, B, C, D, E>(
  a: A,

Lucifier129

function pipe<A, B>(a: A, f: (a: A) => B): B;
function pipe<A, B, C>(a: A, f: (a: A) => B, g: (b: B) => C): C;
function pipe<A, B, C, D>(
	a: A,
	f: (a: A) => B,
	g: (b: B) => C,
	h: (c: C) => D
): D;
function pipe<A, B, C, D, E>(
	a: A,

Lucifier129

use std::collections::HashMap;
extern crate peg;

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
struct Variable(String);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
enum Value {
  Integer(i32),
  Variable(Variable),

Lucifier129

// library
type Handler<T, R> = [new (...args: any) => T, (input: T) => R];

type HandlerPattern<T extends Handler<any, any>> = T extends Handler<
  infer Pattern,
  any
>
  ? Pattern
  : unknown;

Lucifier129

type Prettier<T> = {
  [key in keyof T]: T[key];
}

type Tagged<Tag extends string> = {
  tag: Tag;
};

type Field<Key extends string, Value> = {
  [key in Key]: Value;

Lucifier129

domain TodoInputDomain {
  state TodoInput = ''

  command updateTodoInput(newTodoInput: string) {
    return TodoInput.new(newTodoInput)
  }
}

type Todo = {

Lucifier129

// type utils
type UnionToIntersection<T> = (T extends any ? (x: T) => any : never) extends (
  x: infer R
) => any
  ? R
  : never;

type UnionOf<T extends object> = T[keyof T];

type IntersectionOf<T extends object> = UnionToIntersection<UnionOf<T>>;