withingFuncton

symbolMap.js

const run = Symbol('run');
const map = Symbol('map');
const ask = Symbol('ask');
const of = Symbol('of');
const flatmap = Symbol('flatmap');

Function[of] = function(x) { return _ => x; };

Function.prototype[flatmap] = function(f) {
    return s => f(this(s))(s);
};
Function.prototype[run] = function (env) {
  return this(env);
};
Function.prototype[map] = function (f) {
  return x => f(this(x));
};
Function[ask] = () => x => x;

const append: any = (str: string) =>
  Reader(R.identity)
    .map((env: any) => R.concat(str, env));

Reader.ask().map((env: string) => R.concat(str, env));
  Reader((env: string) => R.concat(str, env));
Reader(R.identity)
    .map((env: any) => R.concat(str, env));