take(): Switch-case as an expression

example.js

/*
 * It takes an expression and a handler object
 * that consists of potential actual values of
 * the given expression.
 *
 * The function calls either the
 * matching method or the default defined in
 * handler object (if defined).
 */
function take(expression, handler) {
  return handler[expression]
    ? handler[expression]()
    : handler.default
      ? handler.default()
      : undefined
}

/* EXAMPLE USE */

// Some hardcoded value.
var foo = 'foo'

// A variable whose value is assigned randomly.
var bar = Math.random() >= .66
  ? ' bar'
  : Math.random() >= .5
    ? ' baz'
    : ''

// In effect, computedValue will be random.
var computedValue = foo + bar

/*
 * Take computedValue as an expression and
 * assign a value to lorem depending on the
 * computedValue.
 * Pretty much the same logic that goes into
 * a switch-case statement.
 */
var lorem = take(computedValue, {
  foo: () =>
    'it is foo',

  ['foo bar']: () =>
    'it is foo bar',

  default: () =>
    'none'
})

console.log('lorem:', lorem)