Ur/Web's [0] pretty obscure but also does this. As does Opa [1]. [0] http://impredicative.com/ur/ http://impredicative.com/ur/ [1] http://opalang.org/ http://

Ur/Web's [0] pretty obscure but also does this. As does Opa [1]. [0] http://impredicative.com/ur/ http://impredicative.com/ur/ [1] http://opalang.org/ http://opalang.org/