core: Add a Uri variant for scratch buffers

helix-core/src/uri.rs

@@ -1,18 +1,44 @@
 use std::{
     fmt,
+    num::NonZeroUsize,
     path::{Path, PathBuf},
     sync::Arc,
 };
 
+// uses NonZeroUsize so Option<DocumentId> takes the same space
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub struct DocumentId(NonZeroUsize);
+
+impl DocumentId {
+    pub const MAX: Self = Self(unsafe { NonZeroUsize::new_unchecked(usize::MAX) });
+
+    pub fn next(&self) -> Self {
+        // Safety: adding 1 from 1 is fine, probably impossible to reach usize max
+        Self(unsafe { NonZeroUsize::new_unchecked(self.0.get() + 1) })
+    }
+}
+
+impl Default for DocumentId {
+    fn default() -> DocumentId {
+        // Safety: 1 is non-zero
+        DocumentId(unsafe { NonZeroUsize::new_unchecked(1) })
+    }
+}
+
+impl std::fmt::Display for DocumentId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
 /// A generic pointer to a file location.
 ///
-/// Currently this type only supports paths to local files.
+/// Cloning this type is cheap: the internal representation uses an Arc or data which is Copy.
-///
-/// Cloning this type is cheap: the internal representation uses an Arc.
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 #[non_exhaustive]
 pub enum Uri {
     File(Arc<Path>),
+    Scratch(DocumentId),
 }
 
 impl Uri {
@@ -21,12 +47,14 @@ impl Uri {
     pub fn to_url(&self) -> Result<url::Url, ()> {
         match self {
             Uri::File(path) => url::Url::from_file_path(path),
+            Uri::Scratch(_) => Err(()),
         }
     }
 
     pub fn as_path(&self) -> Option<&Path> {
         match self {
             Self::File(path) => Some(path),
+            Self::Scratch(_) => None,
         }
     }
 }
@@ -41,6 +69,7 @@ impl fmt::Display for Uri {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Self::File(path) => write!(f, "{}", path.display()),
+            Self::Scratch(id) => write!(f, "[scratch {id}]"),
         }
     }
 }

helix-term/src/commands/lsp.rs

@@ -335,9 +335,7 @@ pub fn symbol_picker(cx: &mut Context) {
             let request = language_server.document_symbols(doc.identifier()).unwrap();
             let offset_encoding = language_server.offset_encoding();
             let doc_id = doc.identifier();
-            let doc_uri = doc
+            let doc_uri = doc.uri();
-                .uri()
-                .expect("docs with active language servers must be backed by paths");
 
             async move {
                 let symbols = match request.await? {
@@ -555,12 +553,11 @@ pub fn workspace_symbol_picker(cx: &mut Context) {
 
 pub fn diagnostics_picker(cx: &mut Context) {
     let doc = doc!(cx.editor);
-    if let Some(uri) = doc.uri() {
+    let uri = doc.uri();
     let diagnostics = cx.editor.diagnostics.get(&uri).cloned().unwrap_or_default();
     let picker = diag_picker(cx, [(uri, diagnostics)], DiagnosticsFormat::HideSourcePath);
     cx.push_layer(Box::new(overlaid(picker)));
 }
-}
 
 pub fn workspace_diagnostics_picker(cx: &mut Context) {
     // TODO not yet filtered by LanguageServerFeature, need to do something similar as Document::shown_diagnostics here for all open documents

helix-view/src/document.rs

@@ -1905,8 +1905,11 @@ impl Document {
         Url::from_file_path(self.path()?).ok()
     }
 
-    pub fn uri(&self) -> Option<helix_core::Uri> {
+    pub fn uri(&self) -> helix_core::Uri {
-        Some(self.path()?.clone().into())
+        self.path
+            .clone()
+            .map(|path| path.into())
+            .unwrap_or(helix_core::Uri::Scratch(self.id))
     }
 
     #[inline]

helix-view/src/editor.rs

@@ -29,7 +29,6 @@ use std::{
     collections::{BTreeMap, HashMap, HashSet},
     fs,
     io::{self, stdin},
-    num::NonZeroUsize,
     path::{Path, PathBuf},
     pin::Pin,
     sync::Arc,
@@ -1711,9 +1710,7 @@ impl Editor {
     /// Generate an id for a new document and register it.
     fn new_document(&mut self, mut doc: Document) -> DocumentId {
         let id = self.next_document_id;
-        // Safety: adding 1 from 1 is fine, probably impossible to reach usize max
+        self.next_document_id = self.next_document_id.next();
-        self.next_document_id =
-            DocumentId(unsafe { NonZeroUsize::new_unchecked(self.next_document_id.0.get() + 1) });
         doc.id = id;
         self.documents.insert(id, doc);
 
@@ -2031,9 +2028,8 @@ impl Editor {
     ) -> impl Iterator<Item = helix_core::Diagnostic> + 'a {
         let text = document.text().clone();
         let language_config = document.language.clone();
-        document
+        diagnostics
-            .uri()
+            .get(&document.uri())
-            .and_then(|uri| diagnostics.get(&uri))
             .map(|diags| {
                 diags.iter().filter_map(move |(diagnostic, provider)| {
                     let server_id = provider.language_server_id()?;

helix-view/src/handlers/diagnostics.rs

@@ -1,5 +1,4 @@
 use std::cell::Cell;
-use std::num::NonZeroUsize;
 use std::sync::atomic::{self, AtomicUsize};
 use std::sync::Arc;
 use std::time::Duration;
@@ -86,7 +85,7 @@ impl DiagnosticsHandler {
             active_generation,
             generation: Cell::new(0),
             events,
-            last_doc: Cell::new(DocumentId(NonZeroUsize::new(usize::MAX).unwrap())),
+            last_doc: Cell::new(DocumentId::MAX),
             last_cursor_line: Cell::new(usize::MAX),
             active: true,
         }

helix-view/src/handlers/lsp.rs

@@ -289,10 +289,7 @@ impl Editor {
         version: Option<i32>,
         mut diagnostics: Vec<lsp::Diagnostic>,
     ) {
-        let doc = self
+        let doc = self.documents.values_mut().find(|doc| doc.uri() == uri);
-            .documents
-            .values_mut()
-            .find(|doc| doc.uri().is_some_and(|u| u == uri));
 
         if let Some((version, doc)) = version.zip(doc.as_ref()) {
             if version != doc.version() {

helix-view/src/lib.rs

@@ -20,25 +20,6 @@ pub mod theme;
 pub mod tree;
 pub mod view;
 
-use std::num::NonZeroUsize;
-
-// uses NonZeroUsize so Option<DocumentId> use a byte rather than two
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
-pub struct DocumentId(NonZeroUsize);
-
-impl Default for DocumentId {
-    fn default() -> DocumentId {
-        // Safety: 1 is non-zero
-        DocumentId(unsafe { NonZeroUsize::new_unchecked(1) })
-    }
-}
-
-impl std::fmt::Display for DocumentId {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.write_fmt(format_args!("{}", self.0))
-    }
-}
-
 slotmap::new_key_type! {
     pub struct ViewId;
 }
@@ -78,5 +59,6 @@ pub use action::Action;
 pub use document::Document;
 pub use editor::Editor;
 use helix_core::char_idx_at_visual_offset;
+pub use helix_core::uri::DocumentId;
 pub use theme::Theme;
 pub use view::View;