RE: [Caml-list] Defining a family of functors

["David Allsopp" <dra-news@metastack.com>]

> > On the other hand, it was pointed to me that Alain already wrote a
> > compiler patch implementing first-class modules.
> 
> That's right.

I have two questions - the first of which will probably demonstrate my lack of skill with the OCaml module system.

1. Does first-class modules, as with first-class functions mean that you can pass them around in code? For example, I have a web-app where all of the stuff which has to access databases is put into a single module with a known signature DB. I then have two modules MSSQLDriver and PGSQLDriver which implement the database functions for two different back-ends and have in DB.ml

module DB = MSSQLDriver
include DB

So when I build for Postgres, I just change the module statement and recompile. Would first class modules allow me to read the back-end configuration from a config file and write something like:

module DB = if Config.driver = `MSSQL then MSSQLDriver else PGSQLDriver

Or is it about something totally different? :o)

2. Is this patch intended for a future version of OCaml or just for research purposes?


David