block statement

[bounceme]

shouldn't be too difficult

[bounceme]

So this works fine, it's just really slow right now and i have no idea why. also this is what this pr changes:

{
  var i = 0,
    l = 5
}
// vs (as if it were an object)
{
  var i = 0,
  l = 5
}

[bounceme]

so there is a slight decrease in performance with this pr however this uses the same algorithm from https://github.com/sweet-js/sweet.js/wiki/design#give-lookbehind-to-the-reader which the acorn parser also uses. it actually is basically the same as what i had originally but with support for labeled block statements and plain block statements.

My results with https://github.com/sanctuary-js/sanctuary-def/blob/master/index.js

block : 10.327 seconds
dev : 8.689 seconds

[bounceme]

will probably merge this tomorrow evening after some more testing