Writing Your First Sweet.js Macro(jlongster.com)

    macro for {
      rule { {$x <- $y:expr;} {$z:expr} } => {
        $y.forEach(function($x) { $z });
      }
    
      rule { {$x <- $y:expr; $($a <- $b:expr) (;) ... } {$z:expr} } => {
        $y.forEach(function($x) {
          for { $($a <- $b;) ... } {
            $z
          }
        })
      }
    }
    for {
      i <- [1,2,3];
      j <- [3,2,1];
      k <- [5,5,5];
    } {
      console.log(i + j + k)
    }