ran into another type inference problem

src/syntax/pretty.rs

@@ -105,6 +105,11 @@ where
                 let comma_sepped_args = allocator.intersperse(args, CommaSep {});
                 call.append(comma_sepped_args.parens())
             }
+            Expression::Call(_, fun, args) => {
+                let args = args.iter().map(|x| x.pretty(allocator));
+                let comma_sepped_args = allocator.intersperse(args, CommaSep {});
+                fun.pretty(allocator).append(comma_sepped_args.parens())
+            }
             Expression::Block(_, stmts) => match stmts.split_last() {
                 None => allocator.text("()"),
                 Some((last, &[])) => last.pretty(allocator),
@@ -167,7 +172,7 @@ fn type_suffix(x: &Option<ConstantType>) -> &'static str {
 }
 
 #[derive(Clone, Copy)]
-struct CommaSep {}
+pub struct CommaSep {}
 
 impl<'a, D, A> Pretty<'a, D, A> for CommaSep
 where