Using with Core causes 'The function applied to this argument has type ?sep:string -> string'

[gregberns]

I'm new to OCaml and started using pgocaml but ran into an issue immediately because I used Core in the same module.

It was suggested I open an issue to see the problem could be mitigated in the library.

The issue is when I added Core and pgocaml's PPX in the same module, the compile fails.

With this code:

open Core
open PGOCaml
let () =
  let dbh = PGOCaml.connect () in
  let insert name salary =
    [%pgsql dbh "insert into employees (name, salary) VALUES ($name, $salary)"]
  in
  ignore(insert "Chris" 1_000.0);

When compiled:

File "bin/main.ml", line 20, characters 6-11:
20 |     [%pgsql dbh "insert into employees (name, salary) VALUES ($name, $salary)"]
           ^^^^^
Error: The function applied to this argument has type ?sep:string -> string
This argument cannot be applied without label

I'm pretty sure the issue is around here uses the String.concat with Core is not compatible.

[gregberns]

Re-opening after editing/updating the initial issue.