partial_application.js

let tee = (a) => {console.log(String(a)); return a}

// our applicator
let $_ = (n) => {
  let args = new Array(n);
  for (let i = 1; i <= n; i++) {
    args[i-1] = `$${i}`
  }
  return (raw, ...values) =>
    Function(...args.concat(tee('return ' + raw.reduce(
      (src,str,i) => {
        return src + values[i-1] + str
      }
    ).trim())));
}

let just_a_sec = $_(1)`
  setTimeout($1, 1000)
`

just_a_sec((_)=>
  alert('ok')
)