Coffeescript like `do` expression

do.macro.sjs

/*

Immediately invoke a block with scopped variables

```
do (foo = 'bar') {
  ...
}
```

The block can be optionally named

*/

let do = macro {
	rule { () => $body:expr } => {
		(function () { return $body }())
	}
	rule { ($($symbol:ident = $value:expr) (,) ...) => $body:expr } => {
		(function ($symbol (,) ...) { return $body }($value (,) ...))
	}
	rule { () $body } => {
		(function () $body ())
	}
	rule { $name:ident () $body } => {
		(function $name() $body ())
	}
	rule { ($($symbol:ident = $value:expr) (,) ...) $body } => {
		(function ($symbol (,) ...) $body ($value (,) ...))
	}
	rule { $name:ident ($($symbol:ident = $value:expr) (,) ...) $body } => {
		(function $name($symbol (,) ...) $body ($value (,) ...))
	}
	rule { $body } => { do $body }
}

export do;