Add DeclarationDescriptor and ReferenceDescriptor

Fixes #142
Fixes #146

Author: kjeremy

crates/ra_analysis/src/descriptors/mod.rs

@@ -1,8 +1,11 @@
 pub(crate) mod module;
 
+use ra_editor::resolve_local_name;
+
 use ra_syntax::{
     ast::{self, AstNode, NameOwner},
     text_utils::is_subrange,
+    TextRange
 };
 
 #[derive(Debug, Clone)]
@@ -61,3 +64,49 @@ impl FnDescriptor {
         res
     }
 }
+
+#[derive(Debug)]
+pub struct ReferenceDescriptor {
+    pub range: TextRange,
+    pub name: String
+}
+
+#[derive(Debug)]
+pub struct DeclarationDescriptor<'a> {
+    pat: ast::BindPat<'a>,
+    pub range: TextRange
+}
+
+impl<'a> DeclarationDescriptor<'a> {
+    pub fn new(pat: ast::BindPat) -> DeclarationDescriptor {
+        let range = pat.syntax().range();
+
+        DeclarationDescriptor {
+            pat,
+            range
+        }
+    }
+
+    pub fn find_all_refs(&self) -> Vec<ReferenceDescriptor> {
+        let name = match self.pat.name() {
+            Some(name) => name,
+            None => return Default::default()
+        };
+
+        let fn_def = match name.syntax().ancestors().find_map(ast::FnDef::cast) {
+            Some(def) => def,
+            None => return Default::default()
+        };
+
+        let refs : Vec<_> = fn_def.syntax().descendants()
+            .filter_map(ast::NameRef::cast)
+            .filter(|name_ref| resolve_local_name(*name_ref) == Some((name.text(), name.syntax().range())))
+            .map(|name_ref| ReferenceDescriptor {
+                name: name_ref.syntax().text().to_string(),
+                range : name_ref.syntax().range(),
+            })
+            .collect();
+
+        refs
+    }
+}

crates/ra_analysis/src/imp.rs

@@ -17,7 +17,7 @@ use rustc_hash::FxHashSet;
 
 use crate::{
     descriptors::module::{ModuleTree, Problem},
-    descriptors::{FnDescriptor},
+    descriptors::{DeclarationDescriptor, FnDescriptor},
     roots::{ReadonlySourceRoot, SourceRoot, WritableSourceRoot},
     CrateGraph, CrateId, Diagnostic, FileId, FileResolver, FileSystemEdit, Position,
     Query, SourceChange, SourceFileEdit, Cancelable,
@@ -258,6 +258,17 @@ impl AnalysisImpl {
 
         let mut ret = vec![];
 
+        if let Some(binding) = find_node_at_offset::<ast::BindPat>(syntax, offset) {
+            let decl = DeclarationDescriptor::new(binding);
+
+            ret.push((file_id, decl.range));
+
+            ret.extend(decl.find_all_refs().into_iter()
+                .map(|ref_desc| (file_id, ref_desc.range )));
+
+            return ret;
+        }
+
         // Find the symbol we are looking for
         if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(syntax, offset) {
 

crates/ra_analysis/tests/tests.rs

@@ -264,3 +264,14 @@ fn test_find_all_refs_for_param_inside() {
     let refs = get_all_refs(code);
     assert_eq!(refs.len(), 2);
 }
+
+#[test]
+fn test_find_all_refs_for_fn_param() {
+    let code = r#"
+    fn foo(i<|> : u32) -> u32 {
+        i
+    }"#;
+
+    let refs = get_all_refs(code);
+    assert_eq!(refs.len(), 2);
+}