import { inspect } from "node:util";
import { assignFn } from "../generics/generics.js";

function inspectDynamic(_depth, options, inspect) {
  return `${inspect(this.i, options)} :: ${inspect(this.t, options)}`;
}

export const newDynamic = i => t => ({
  i, t,
  [inspect.custom]: inspectDynamic,
});

export const getInst = lnk => lnk.i;
export const getType = lnk => lnk.t;

export const apply = input => fun => {
  const inputType = getType(input)
  const funType = getType(fun);
  const outputType = assignFn(funType, inputType);

  const inputValue = getInst(input);
  const funValue = getInst(fun);
  const outputValue = funValue(inputValue);

  return newDynamic(outputValue, outputType);
};