1 files changed, 69 insertions, 0 deletions

diff --git a/crates/vfs/src/loader.rs b/crates/vfs/src/loader.rs
new file mode 100644
index 000000000..5a0ca68f3
--- /dev/null
+++ b/crates/vfs/src/loader.rs
@@ -0,0 +1,69 @@
+//! Object safe interface for file watching and reading.
+use std::fmt;
+
+use paths::AbsPathBuf;
+
+pub enum Entry {
+    Files(Vec<AbsPathBuf>),
+    Directory { path: AbsPathBuf, globs: Vec<String> },
+}
+
+pub struct Config {
+    pub load: Vec<Entry>,
+    pub watch: Vec<usize>,
+}
+
+pub enum Message {
+    DidSwitchConfig { n_entries: usize },
+    DidLoadAllEntries,
+    Loaded { files: Vec<(AbsPathBuf, Option<Vec<u8>>)> },
+}
+
+pub type Sender = Box<dyn Fn(Message) + Send>;
+
+pub trait Handle: fmt::Debug {
+    fn spawn(sender: Sender) -> Self
+    where
+        Self: Sized;
+    fn set_config(&mut self, config: Config);
+    fn invalidate(&mut self, path: AbsPathBuf);
+    fn load_sync(&mut self, path: &AbsPathBuf) -> Option<Vec<u8>>;
+}
+
+impl Entry {
+    pub fn rs_files_recursively(base: AbsPathBuf) -> Entry {
+        Entry::Directory { path: base, globs: globs(&["*.rs"]) }
+    }
+    pub fn local_cargo_package(base: AbsPathBuf) -> Entry {
+        Entry::Directory { path: base, globs: globs(&["*.rs", "!/target/"]) }
+    }
+    pub fn cargo_package_dependency(base: AbsPathBuf) -> Entry {
+        Entry::Directory {
+            path: base,
+            globs: globs(&["*.rs", "!/tests/", "!/examples/", "!/benches/"]),
+        }
+    }
+}
+
+fn globs(globs: &[&str]) -> Vec<String> {
+    globs.iter().map(|it| it.to_string()).collect()
+}
+
+impl fmt::Debug for Message {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Message::Loaded { files } => {
+                f.debug_struct("Loaded").field("n_files", &files.len()).finish()
+            }
+            Message::DidSwitchConfig { n_entries } => {
+                f.debug_struct("DidSwitchConfig").field("n_entries", n_entries).finish()
+            }
+            Message::DidLoadAllEntries => f.debug_struct("DidLoadAllEntries").finish(),
+        }
+    }
+}
+
+#[test]
+fn handle_is_object_safe() {
+    fn _assert(_: &dyn Handle) {}
+}