I answered this on twitter: https://twitter.com/left_pad/status/936721918840983554 https://twitter.com/left_pad/status/936721918840983554 And added this option

I answered this on twitter: https://twitter.com/left_pad/status/936721918840983554 https://twitter.com/left_pad/status/936721918840983554 And added this option + optimization for v7 https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-for-of#assumearray https://github.com/babel/babel/tree/master/packages/babel-pl... so can look forward to that now =D.