Add parameterised methods safely to prototypes etc.

metho.js

function add(target, f, outerSyntax=false){
  return f.length ?
    outerSyntax ?
      addProperty(target, f)
    :
      addWithParams(target, f)
  :
    addSimple(target, f)
}

function addProperty(target, f) {
  const s = Symbol()
  target[s] = f
  return s
}

function addWithParams(target, f) {
  return(function(...args) {
    const s = Symbol()
    Object.defineProperty(target, s, {
      get: function() {
        delete target[s]
        return f.apply(this, args)
      }
    })
    return s
  })
}

function addSimple(target, f) {
  const s = Symbol()
  Object.defineProperty(target, s, {get: f})
  return s
}


to = add(Number.prototype, function(toNumber) {
  return this + '--' + toNumber
})

to2 = add(Number.prototype, function(toNumber) {
  return this + '--' + toNumber
}, true)

half = add(Number.prototype, function() { return this/2 })
triple = add(Number.prototype, function() { return this*3 })
hex = add(Number.prototype, function() { return this.toString(16) })
bin = add(Number.prototype, function() { return this.toString(2) })

upper = add(String.prototype, function() { return this.toUpperCase() })
reverse = add(String.prototype, function() { return [...this].reverse().join('')})


console.log(14[to(16)])
console.log(14[to2](16))

console.log('Jonathan'[reverse][upper])


// may well need the ability to add descriptions for these Symbols that are flying around