I'm curious, how does it differ (or plan to differ) from Reason? It seems that the language implements a _subset_ of reasonml features with slightly different s

I'm curious, how does it differ (or plan to differ) from Reason? It seems that the language implements a _subset_ of reasonml features with slightly different syntax. The sources even contain some files from OCaml that are translated to Reason. Maybe the doc isn't complete or I miss something, what about the module system, type inference, polymorphic variants?..