Working example

src/project/loading/file_loader.rs

@@ -0,0 +1,34 @@
+use std::fs::read_to_string;
+use std::path::PathBuf;
+
+use super::{Loaded, Loader, LoadingError};
+
+pub fn file_loader(proj: PathBuf) -> impl Loader + 'static {
+  move |path: &[&str]| {
+    let dirpath = proj.join(path.join("/"));
+    if dirpath.is_dir() || dirpath.is_symlink() {
+      return Ok(Loaded::Namespace(
+        dirpath.read_dir()?
+          .filter_map(|entr| {
+            let ent = entr.ok()?;
+            let typ = ent.file_type().ok()?;
+            let path = ent.path();
+            if typ.is_dir() || typ.is_symlink() {
+              Some(ent.file_name().to_string_lossy().into_owned())
+            } else if typ.is_file() && path.extension()? == "orc" {
+              Some(path.file_stem()?.to_string_lossy().into_owned())
+            } else { None }
+          })
+          .collect()
+      ))
+    }
+    let orcfile = dirpath.with_extension("orc");
+    if orcfile.is_file() {
+      read_to_string(orcfile).map(Loaded::Module).map_err(LoadingError::from)
+    } else {
+      let pathstr = dirpath.to_string_lossy().into_owned();
+      Err(if dirpath.exists() { LoadingError::UnknownNode(pathstr) }
+      else { LoadingError::Missing(pathstr) })
+    }
+  }
+}