Use UppercaseIdent over PlatformRigids

compiler/fmt/src/annotation.rs

@@ -4,6 +4,7 @@ use crate::{
     Buf,
 };
 use roc_parse::ast::{AliasHeader, AssignedField, Expr, Tag, TypeAnnotation};
+use roc_parse::ident::UppercaseIdent;
 use roc_region::all::Loc;
 
 /// Does an AST node need parens around it?
@@ -107,6 +108,22 @@ where
     }
 }
 
+impl<'a> Formattable for UppercaseIdent<'a> {
+    fn is_multiline(&self) -> bool {
+        false
+    }
+
+    fn format_with_options<'buf>(
+        &self,
+        buf: &mut Buf<'buf>,
+        _parens: Parens,
+        _newlines: Newlines,
+        _indent: u16,
+    ) {
+        buf.push_str((*self).into())
+    }
+}
+
 impl<'a> Formattable for TypeAnnotation<'a> {
     fn is_multiline(&self) -> bool {
         use roc_parse::ast::TypeAnnotation::*;