rest - decorate functions so you can bind "rest" arguments with f.rest().

rest.js

// Decorate a function with a method that allows you to bind "rest" args
// (everything except the first argument).
// Usage:
//
//     const f = rest((a, b, c) => a + b + c)
//     const fbc = f.rest("b", "c")
//     fbc("a")
//     // "abc"
const rest = f => {
  f.rest = (...rest) => v => f(v, ...rest)
  return f
}