One attempt to make arrow functions from es6

es6-arrows.sjs

macro => {
	rule infix { ( $arg:ident (,) ... ) | { $body ... $last:expr } } => {
		(function x( $arg (,) ... ) {
			$( $body) ...
			return $last
		}).bind(this);
	}
	rule infix { ( $arg:ident (,) ... ) | $last:expr } => {
		(function x( $arg (,) ... ) {
			return $last
		}).bind(this);
	}
	rule infix { () | { $body ... $last:expr } } => {
		(function x( ) { 
			$body ...;
			return $last
		}).bind(this);
	}
	rule infix { $x | { $body ... $last:expr } } => {
		(function x($x) { 
			$body ...;
			return $last
		}).bind(this);
	}
	rule infix { $x | $last:expr } => {
		(function x($x) { 
			return $last
		}).bind(this);
	}
}

The semicolons error on something like [1, 2, 3].map(x => x+1);