Index all assigned variables

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 ## 2024-10
 
+- Objects assigned at top level are now indexed, in addition to assigned functions. When a name is assigned multiple times, we now only index the first occurrence. This allows you to jump to the first "declaration" of the variable. In the future we'll improve this mechanism so that you can jump to the most recent assignment.
+
+  We also index `method(generic, class) <-` assignment to help with S7 development. This might be replaced by a "Find implementations" mechanism in the future.
+
 - Results from completions have been improved with extra details.
   Package functions now display the package name (posit-dev/positron#5225)
   and namespace completions now display `::` to hint at what is being

crates/ark/src/lsp/completions/completion_item.rs

@@ -273,6 +273,14 @@ pub(super) unsafe fn completion_item_from_object(
     Ok(item)
 }
 
+pub(super) fn completion_item_from_variable(name: &str) -> anyhow::Result<CompletionItem> {
+    let mut item = completion_item(String::from(name), CompletionData::Object {
+        name: String::from(name),
+    })?;
+    item.kind = Some(CompletionItemKind::VALUE);
+    Ok(item)
+}
+
 pub(super) unsafe fn completion_item_from_promise(
     name: &str,
     object: SEXP,

crates/ark/src/lsp/completions/sources/composite/call.rs

@@ -271,6 +271,7 @@ fn completions_from_workspace_arguments(
             // Not a function
             return Ok(None);
         },
+        indexer::IndexEntryData::Variable { .. } => return Ok(None),
     }
 
     // Only 1 call worth of arguments are added to the completion set.

crates/ark/src/lsp/completions/sources/composite/workspace.rs

@@ -14,6 +14,7 @@ use tower_lsp::lsp_types::MarkupContent;
 use tower_lsp::lsp_types::MarkupKind;
 
 use crate::lsp::completions::completion_item::completion_item_from_function;
+use crate::lsp::completions::completion_item::completion_item_from_variable;
 use crate::lsp::completions::sources::utils::filter_out_dot_prefixes;
 use crate::lsp::document_context::DocumentContext;
 use crate::lsp::indexer;
@@ -97,6 +98,16 @@ pub(super) fn completions_from_workspace(
             },
 
             indexer::IndexEntryData::Section { level: _, title: _ } => {},
+            indexer::IndexEntryData::Variable { name } => {
+                let completion = match completion_item_from_variable(name) {
+                    Ok(item) => item,
+                    Err(err) => {
+                        log::error!("{err:?}");
+                        return;
+                    },
+                };
+                completions.push(completion);
+            },
         }
     });
 

crates/ark/src/lsp/indexer.rs

@@ -32,6 +32,9 @@ use crate::treesitter::NodeTypeExt;
 
 #[derive(Clone, Debug)]
 pub enum IndexEntryData {
+    Variable {
+        name: String,
+    },
     Function {
         name: String,
         arguments: Vec<String>,
@@ -117,7 +120,13 @@ fn insert(path: &Path, entry: IndexEntry) -> anyhow::Result<()> {
     let path = str_from_path(path)?;
 
     let index = index.entry(path.to_string()).or_default();
-    index.insert(entry.key.clone(), entry);
+
+    // Retain the first occurrence in the index. In the future we'll track every occurrences and
+    // their scopes but for now we only track the first definition of an object (in a way, its
+    // declaration).
+    if !index.contains_key(&entry.key) {
+        index.insert(entry.key.clone(), entry);
+    }
 
     Ok(())
 }
@@ -205,6 +214,11 @@ fn index_node(path: &Path, contents: &Rope, node: &Node) -> anyhow::Result<Optio
         return Ok(Some(entry));
     }
 
+    // Should be after function indexing as this is a more general case
+    if let Ok(Some(entry)) = index_variable(path, contents, node) {
+        return Ok(Some(entry));
+    }
+
     if let Ok(Some(entry)) = index_comment(path, contents, node) {
         return Ok(Some(entry));
     }
@@ -262,6 +276,40 @@ fn index_function(
     }))
 }
 
+fn index_variable(
+    _path: &Path,
+    contents: &Rope,
+    node: &Node,
+) -> anyhow::Result<Option<IndexEntry>> {
+    if !matches!(
+        node.node_type(),
+        NodeType::BinaryOperator(BinaryOperatorType::LeftAssignment) |
+            NodeType::BinaryOperator(BinaryOperatorType::EqualsAssignment)
+    ) {
+        return Ok(None);
+    }
+
+    let Some(lhs) = node.child_by_field_name("lhs") else {
+        return Ok(None);
+    };
+
+    let lhs_text = contents.node_slice(&lhs)?.to_string();
+
+    // Super hacky but let's wait until the typed API to do better
+    if !lhs_text.starts_with("method(") && !lhs.is_identifier_or_string() {
+        return Ok(None);
+    }
+
+    let start = convert_point_to_position(contents, lhs.start_position());
+    let end = convert_point_to_position(contents, lhs.end_position());
+
+    Ok(Some(IndexEntry {
+        key: lhs_text.clone(),
+        range: Range { start, end },
+        data: IndexEntryData::Variable { name: lhs_text },
+    }))
+}
+
 fn index_comment(_path: &Path, contents: &Rope, node: &Node) -> anyhow::Result<Option<IndexEntry>> {
     // check for comment
     node.is_comment().into_result()?;

crates/ark/src/lsp/symbols.rs

@@ -95,6 +95,19 @@ pub fn symbols(params: &WorkspaceSymbolParams) -> anyhow::Result<Vec<SymbolInfor
                     container_name: None,
                 });
             },
+            IndexEntryData::Variable { name } => {
+                info.push(SymbolInformation {
+                    name: name.clone(),
+                    kind: SymbolKind::VARIABLE,
+                    location: Location {
+                        uri: Url::from_file_path(path).unwrap(),
+                        range: entry.range,
+                    },
+                    tags: None,
+                    deprecated: None,
+                    container_name: None,
+                });
+            },
         };
     });