smear

smears (or spreads) a single array parameter across a function's arguments.

Note: if you're using an es6 runtime or compiler (such as babel), check out destructuring of parameters. It's a faster and prettier approach to the problem smear solves.

Smear turns a function that would normally take comma-separated parameters and turns it into one that takes a single parameter -- an array. Technically it unspreads the function.

This is particularly useful with promises, which must resolve to a single value (much like a synchronous return value). Some Promise implementations will add a .spread() function to the Promise prototype, but this is a non-standard interface and is incompatible with native promises.

Example

Turns this:

Promise.resolve([1, 2, 3]).then(function (args) {
  var one = args[0];
  var two = args[1];
  var three = args[2];
})

into this:

Promise.resolve([1, 2, 3]).then(spread(function (one, two, three) {
  console.log('much better!');
}));

API

function smear(fn)

fn - a function accepting a comma-separated list of parameters.

Smear returns a new function that accepts a single parameter of an array, and spreads it out to fn.