Semi optional deriving arguments using ppxlib

Community
1

I’m trying to use ppxlib (actually, ppx_type_conv which now is a part of ppxlib) and my goal is to specify plugin arguments as I want. More precisely, ppxlib currently supports arguments like
[@@deriving plugin_name ~flag1 ~flag2 ...] where presence of labeled argument translates to true and absence to false.

Another way to declare arguments is to replace bool type by expression type, i.e. [@@deriving plugin_name ~arg1:e1 ~arg2:e2 ...] where the user obliged to specify expression for the labeled argument.

I want to specify plugin arguments that have type expression option and make specifying expressions optional. Can you help me to do it?

[ANN] ppxlib - Jane Street ppx infrastructure now on github
2

Sure. If you look at the implementation of Ppxlib.Deriving.Args.arg, you just need to set the detault field.

BTW, i just saw your post by chance, I think it is best to post such questions on the project directly