Hover for associated items in patterns

[rust.git] / crates / ra_ide_api / src / goto_definition.rs

diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index 6fa430754780f0f89b10b4d269f62f669034d04b..286ade0a48e1ccaa9db9946dea25cb18631b440e 100644 (file)
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -5,7 +5,7 @@
     SyntaxNode,
 };
 use test_utils::tested_by;
-use hir::Resolution;
+use hir::{Pat, Resolution};
 
 use crate::{FilePosition, NavigationTarget, db::RootDatabase, RangeInfo};
 
@@ -47,17 +47,18 @@ pub(crate) fn reference_definition(
     name_ref: &ast::NameRef,
 ) -> ReferenceResult {
     use self::ReferenceResult::*;
-    if let Some(function) =
-        hir::source_binder::function_from_child_node(db, file_id, name_ref.syntax())
-    {
+
+    let function = hir::source_binder::function_from_child_node(db, file_id, name_ref.syntax());
+
+    if let Some(function) = function {
         // Check if it is a method
         if let Some(method_call) = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast) {
             tested_by!(goto_definition_works_for_methods);
             let infer_result = function.infer(db);
-            let syntax_mapping = function.body_syntax_mapping(db);
+            let source_map = function.body_source_map(db);
             let expr = ast::Expr::cast(method_call.syntax()).unwrap();
             if let Some(func) =
-                syntax_mapping.node_expr(expr).and_then(|it| infer_result.method_resolution(it))
+                source_map.node_expr(expr).and_then(|it| infer_result.method_resolution(it))
             {
                 return Exact(NavigationTarget::from_function(db, func));
             };
@@ -66,10 +67,10 @@ pub(crate) fn reference_definition(
         if let Some(field_expr) = name_ref.syntax().parent().and_then(ast::FieldExpr::cast) {
             tested_by!(goto_definition_works_for_fields);
             let infer_result = function.infer(db);
-            let syntax_mapping = function.body_syntax_mapping(db);
+            let source_map = function.body_source_map(db);
             let expr = ast::Expr::cast(field_expr.syntax()).unwrap();
             if let Some(field) =
-                syntax_mapping.node_expr(expr).and_then(|it| infer_result.field_resolution(it))
+                source_map.node_expr(expr).and_then(|it| infer_result.field_resolution(it))
             {
                 return Exact(NavigationTarget::from_field(db, field));
             };
@@ -80,11 +81,11 @@ pub(crate) fn reference_definition(
             tested_by!(goto_definition_works_for_named_fields);
 
             let infer_result = function.infer(db);
-            let syntax_mapping = function.body_syntax_mapping(db);
+            let source_map = function.body_source_map(db);
 
             let struct_lit = field_expr.syntax().ancestors().find_map(ast::StructLit::cast);
 
-            if let Some(expr) = struct_lit.and_then(|lit| syntax_mapping.node_expr(lit.into())) {
+            if let Some(expr) = struct_lit.and_then(|lit| source_map.node_expr(lit.into())) {
                 let ty = infer_result[expr].clone();
                 if let hir::Ty::Adt { def_id, .. } = ty {
                     if let hir::AdtDef::Struct(s) = def_id {
@@ -99,6 +100,7 @@ pub(crate) fn reference_definition(
             }
         }
     }
+
     // Try name resolution
     let resolver = hir::source_binder::resolver_for_node(db, file_id, name_ref.syntax());
     if let Some(path) =
@@ -109,9 +111,8 @@ pub(crate) fn reference_definition(
             Some(Resolution::Def(def)) => return Exact(NavigationTarget::from_def(db, def)),
             Some(Resolution::LocalBinding(pat)) => {
                 let body = resolver.body().expect("no body for local binding");
-                let syntax_mapping = body.syntax_mapping(db);
-                let ptr =
-                    syntax_mapping.pat_syntax(pat).expect("pattern not found in syntax mapping");
+                let source_map = body.owner().body_source_map(db);
+                let ptr = source_map.pat_syntax(pat).expect("pattern not found in syntax mapping");
                 let name =
                     path.as_ident().cloned().expect("local binding from a multi-segment path");
                 let nav = NavigationTarget::from_scope_entry(file_id, name, ptr);
@@ -123,9 +124,52 @@ pub(crate) fn reference_definition(
             Some(Resolution::SelfType(_impl_block)) => {
                 // TODO: go to the implemented type
             }
-            None => {}
+            None => {
+                // If we failed to resolve then check associated items
+                if let Some(function) = function {
+                    // Resolve associated item for path expressions
+                    if let Some(path_expr) =
+                        name_ref.syntax().ancestors().find_map(ast::PathExpr::cast)
+                    {
+                        let infer_result = function.infer(db);
+                        let source_map = function.body_source_map(db);
+
+                        if let Some(expr) = ast::Expr::cast(path_expr.syntax()) {
+                            if let Some(res) = source_map
+                                .node_expr(expr)
+                                .and_then(|it| infer_result.assoc_resolutions_for_expr(it.into()))
+                            {
+                                return Exact(NavigationTarget::from_impl_item(db, res));
+                            }
+                        }
+                    }
+
+                    // Resolve associated item for path patterns
+                    if let Some(path_pat) =
+                        name_ref.syntax().ancestors().find_map(ast::PathPat::cast)
+                    {
+                        let infer_result = function.infer(db);
+
+                        if let Some(p) = path_pat.path().and_then(hir::Path::from_ast) {
+                            if let Some(pat_id) =
+                                function.body(db).pats().find_map(|(pat_id, pat)| match pat {
+                                    Pat::Path(ref path) if *path == p => Some(pat_id),
+                                    _ => None,
+                                })
+                            {
+                                if let Some(res) =
+                                    infer_result.assoc_resolutions_for_pat(pat_id.into())
+                                {
+                                    return Exact(NavigationTarget::from_impl_item(db, res));
+                                }
+                            }
+                        }
+                    }
+                }
+            }
         }
     }
+
     // If that fails try the index based approach.
     let navs = crate::symbol_index::index_resolve(db, name_ref)
         .into_iter()