es6 template string function to expand CoffeeScript object notation to JS objects - run with io.js

cson-test.js

var coffee = require("coffee-script")

var x = cson`
  a: 1
  b: 2
`
console.log(x)
// prints: { a: 1, b: 2 }

console.log(cson`
  a: ${x.b}
  b: ${x.a}
`)
// prints: { a: 2, b: 1 }

console.log(cson`[
  1
  2
]`)
// prints: [ 1, 2 ]

console.log(cson`
  a: 1
  b:
    c:
      d: 4
`)
// prints: { a: 1, b: { c: { d: 4 } } }

console.log(cson`
  x: ${JSON.stringify(x)}
`)
// prints: { x: { a: 1, b: 2 } }


//------------------------------------------------------------------------------
function cson(lits) {
  var subs = [].slice.call(arguments, 1)

  var source = []

  for (var i=0; i<subs.length; i++) {
    source.push(lits[i])
    source.push(subs[i])
  }

  source.push(lits[lits.length-1])

  var result
  var source = source.join("")
  var ePrefix = `error compiling '${JSON.stringify(source)}'`

  try {
    result = coffee.compile(source, {bare: true})
  }
  catch (e) {
    throw new Error(`${ePrefix}: error compiling CoffeeScript: '${JSON.stringify(source)}': ${e.message}`)
  }

  try {
    result = eval(result)
  }
  catch (e) {
    throw new Error(`${ePrefix}: error evaluating: '${JSON.stringify(result)}': ${e.message}`)
  }

  return result
}

This is more of an experiment to see what "simpler" JSON object literals might look like. CoffeeScript and eval are overkill, but easy to play with. I should try using my sloppy json parser instead