Working example

src/project/loading/map_loader.rs

@@ -0,0 +1,16 @@
+use std::collections::HashMap;
+
+use super::{Loader, LoadingError, Loaded};
+
+pub fn map_loader<'a, T: Loader + 'a>(mut map: HashMap<&'a str, T>) -> impl Loader + 'a {
+  move |path: &[&str]| {
+    let (key, subpath) = if let Some(sf) = path.split_first() {sf}
+    else {return Ok(Loaded::Module(map.keys().cloned().collect()))};
+    let sub = if let Some(sub) = map.get_mut(key.to_string().as_str()) {sub}
+    else {return Err(
+      if subpath.len() == 0 {LoadingError::UnknownNode(path.join("::"))}
+      else {LoadingError::Missing(path.join("::"))}
+    )};
+    sub.load(subpath)
+  }
+}