see https://forum.rescript-lang.org/t/regexp-result-t-inconsistency/5326 https://github.com/rescript-association/rescript-core/blob/0b4bd00f518430f41bdfc8703b48191b458b4ded/src/Core__RegExp.res#L4 `Js.String2.match_` [here](https://github.com/rescript-lang/rescript-compiler/blob/master/jscomp/others/js_string2.res#L442) is typed as returning `option<array<option<t>>>`