q49706368-Propsal.ts

type SchemaEntry<A, B extends keyof A> =

  | Validator<A[B]>

  | ((obj: Id<A>) => Validator<A[B]>);

type Schema<A extends object> = { [k in keyof A]: SchemaEntry<A, k> };

class Result<T> {}

export class Validator<A> {

  constructor(

    private _validate: (

      obj: A,

      schema: A extends object ? Schema<A> : undefined

    ) => Result<A>

  ) {}

}


function validator<A extends object>(
  v:(object: A, schema: Schema<A>) => Result<A>
) :Validator<A>
function validator<A>(
  v:(object: A) => Result<A>
) :Validator<A>
function validator<A>(
  v:(object: A, schema: any) => Result<A>
) {

  return new Validator<A>(v);

}


const object = <A extends object>(schema: Schema<A>) => {

  return validator<A>((o, s) => {

    // option 1

    for (const k in <Schema<A>>s) {

      if (s.hasOwnProperty(k)) {

        const v = s[k]; // ok

      }

    }



    // option 2

    for (const [k, v] of Object.entries(s)) {

      // v has expected type

    }
    return  null as any as Result<A>;
  });

}