Minimal F# to Java compiler

open Microsoft.FSharp.Quotations.DerivedPatterns

let rec toJava = function
   | Int32 x -> sprintf "%d" x
   | SpecificCall <@@ (+) @@> (None, _, [lhs;rhs]) -> sprintf "(%s+%s)" (toJava lhs) (toJava rhs)
   | _ -> failwith "Not supported"

let toClass expr =
    sprintf """
public class Generated {
   public static void main(String []args){
      System.out.println(%s);
   }
}""" (toJava expr)

toClass <@ 1 + 1 @>