make quicksort use a Pkg-Config.roc file

compiler/load/src/file.rs

@@ -525,6 +525,7 @@ struct ParsedModule<'a> {
 
 #[derive(Debug)]
 enum Msg<'a> {
+    Many(Vec<Msg<'a>>),
     Header(ModuleHeader<'a>),
     Parsed(ParsedModule<'a>),
     CanonicalizedAndConstrained {
@@ -1253,6 +1254,16 @@ fn update<'a>(
     use self::Msg::*;
 
     match msg {
+        Many(messages) => {
+            // enqueue all these message
+            for msg in messages {
+                msg_tx
+                    .send(msg)
+                    .map_err(|_| LoadingProblem::MsgChannelDied)?;
+            }
+
+            Ok(state)
+        }
         Header(header) => {
             log!("loaded header for {:?}", header.module_id);
             let home = header.module_id;
@@ -1868,16 +1879,34 @@ fn parse_header<'a>(
             ident_ids_by_module,
             module_timing,
         )),
-        Ok((ast::Module::App { header }, parse_state)) => Ok(send_header(
+        Ok((ast::Module::App { header }, parse_state)) => {
+            let mut pkg_config_dir = filename.clone();
+            pkg_config_dir.pop();
+
+            let (module_id, app_module_header_msg) = send_header(
                 header.name,
                 filename,
                 header.provides.into_bump_slice(),
                 header.imports.into_bump_slice(),
                 parse_state,
+                module_ids.clone(),
+                ident_ids_by_module.clone(),
+                module_timing,
+            );
+
+            let load_pkg_config_msg = load_pkg_config(
+                arena,
+                &pkg_config_dir,
                 module_ids,
                 ident_ids_by_module,
-            module_timing,
-        )),
+                mode,
+            )?;
+
+            Ok((
+                module_id,
+                Msg::Many(vec![app_module_header_msg, load_pkg_config_msg]),
+            ))
+        }
         Ok((ast::Module::Platform { header }, _parse_state)) => fabricate_effects_module(
             arena,
             module_ids,

examples/quicksort/platform/Pkg-Config.roc

@@ -2,4 +2,4 @@ platform roc/quicksort
     provides []
     requires {}
     imports []
-    effects {}
+    effects Effect {}