type ParserError<T extends string> = { error: true } & T;
type EatWhitespace<State extends string> = string extends State
  ? ParserError<"EatWhitespace got generic string type">
  : State extends ` ${infer State}` | `\n${infer State}`
  ? EatWhitespace<State>
  : State;
type AddKeyValue<
  Memo extends Record<string, any>,
  Key extends string,
  Value extends any,
> = Memo & { [K in Key]: Value };
type ParseJsonObject<
  State extends string,
  Memo extends Record<string, any> = {},
> = string extends State
  ? ParserError<"ParseJsonObject got generic string type">
  : EatWhitespace<State> extends `}${infer State}`
  ? [Memo, State]
  : EatWhitespace<State> extends `"${infer Key}"${infer State}`
  ? EatWhitespace<State> extends `:${infer State}`
    ? ParseJsonValue<State> extends [infer Value, `${infer State}`]
      ? EatWhitespace<State> extends `,${infer State}`
        ? ParseJsonObject<State, AddKeyValue<Memo, Key, Value>>
        : EatWhitespace<State> extends `}${infer State}`
        ? [AddKeyValue<Memo, Key, Value>, State]
        : ParserError<`ParseJsonObject received unexpected token: ${State}`>
      : ParserError<`ParseJsonValue returned unexpected value for: ${State}`>
    : ParserError<`ParseJsonObject received unexpected token: ${State}`>
  : ParserError<`ParseJsonObject received unexpected token: ${State}`>;
type ParseJsonArray<
  State extends string,
  Memo extends any[] = [],
> = string extends State
  ? ParserError<"ParseJsonArray got generic string type">
  : EatWhitespace<State> extends `]${infer State}`
  ? [Memo, State]
  : ParseJsonValue<State> extends [infer Value, `${infer State}`]
  ? EatWhitespace<State> extends `,${infer State}`
    ? ParseJsonArray<EatWhitespace<State>, [...Memo, Value]>
    : EatWhitespace<State> extends `]${infer State}`
    ? [[...Memo, Value], State]
    : ParserError<`ParseJsonArray received unexpected token: ${State}`>
  : ParserError<`ParseJsonValue returned unexpected value for: ${State}`>;
type ParseJsonValue<State extends string> = string extends State
  ? ParserError<"ParseJsonValue got generic string type">
  : EatWhitespace<State> extends `null${infer State}`
  ? [null, State]
  : EatWhitespace<State> extends `true${infer State}`
  ? [true, State]
  : EatWhitespace<State> extends `false${infer State}`
  ? [false, State]
  : EatWhitespace<State> extends `"${infer Value}"${infer State}`
  ? [Value, State]
  : EatWhitespace<State> extends `[${infer State}`
  ? ParseJsonArray<State>
  : EatWhitespace<State> extends `{${infer State}`
  ? ParseJsonObject<State>
  : ParserError<`ParseJsonValue received unexpected token: ${State}`>;
export type ParseJson<T extends string> = ParseJsonValue<T> extends infer Result
  ? Result extends [infer Value, string]
    ? Value
    : Result extends ParserError<any>
    ? Result
    : ParserError<"ParseJsonValue returned unexpected Result">
  : ParserError<"ParseJsonValue returned uninferrable Result">;

type Person =
  ParseJson<'{ "name": "Jamie Kyle", "twitter": "https://twitter.com/buildsghost" }'>;
// {
//   "name": "Jamie Kyle",
// } & {
//   "twitter": "https://twitter.com/buildsghost"
// }

export default class Foo {
  person: Person;
  pooop: Poop;
}
export const person: Person = {
  name: "Jamie Kyle",
  twitter: "https://twitter.com/buildsghost",
};