A useful JS function for running maps on objects; similar to Ruby's Symbol#to_proc &:foo syntax, but more powerful.

ƒ.js

function ƒ(name){
  let v,params=Array.prototype.slice.call(arguments,1);
  return o=>(typeof (v=o[name])==='function' ? v.apply(o,params) : v);
}

a = ["foo", "barmitzvah"]
a.map(ƒ('length'))      // [3, 10]
a.map(ƒ('toUpperCase')) // ["FOO", "BARMITZVAH"]
a.map(ƒ('slice',1))     // ["oo", "armitzvah"]