compile basic function calls

lib/compile/bcc.ml

@@ -33,6 +33,19 @@ let compile modl =
         emit (SLT (sp + 1, sp, ele));
         emit (GET (sp + 1, sp));
         Reg sp
+    | Ast.Call (Var name, args) -> (
+        match Env.find name env with
+        | exception Not_found -> Fmt.failwith "unbound: %S" name
+        | { self; elem } ->
+            List.iteri
+              (fun i arg ->
+                let sp = sp + i + 1 in
+                emit_mov sp (compile_exp env sp arg))
+              args;
+            let idx = Code.cst (Value.of_elem elem) in
+            emit_mov sp idx;
+            emit (CLL (self, sp, List.length args));
+            Reg sp)
     | Ast.Binop (op, lhs, rhs) ->
         let lhs = compile_exp env sp lhs in
         emit_mov sp lhs;