2 files changed, 31 insertions, 11 deletions

diff --git a/crates/ra_ide/src/display/function_signature.rs b/crates/ra_ide/src/display/function_signature.rs
index db3907fe6..9572debd8 100644
--- a/crates/ra_ide/src/display/function_signature.rs
+++ b/crates/ra_ide/src/display/function_signature.rs
@@ -1,5 +1,7 @@
 //! FIXME: write short doc here
 
+// FIXME: this modules relies on strings and AST way too much, and it should be
+// rewritten (matklad 2020-05-07)
 use std::{
     convert::From,
     fmt::{self, Display},
@@ -82,8 +84,8 @@ impl FunctionSignature {
             let ty = field.signature_ty(db);
             let raw_param = format!("{}", ty.display(db));
 
-            if let Some(param_type) = raw_param.split(':').nth(1) {
-                parameter_types.push(param_type[1..].to_string());
+            if let Some(param_type) = raw_param.split(':').nth(1).and_then(|it| it.get(1..)) {
+                parameter_types.push(param_type.to_string());
             } else {
                 // useful when you have tuple struct
                 parameter_types.push(raw_param.clone());
@@ -127,8 +129,8 @@ impl FunctionSignature {
         for field in variant.fields(db).into_iter() {
             let ty = field.signature_ty(db);
             let raw_param = format!("{}", ty.display(db));
-            if let Some(param_type) = raw_param.split(':').nth(1) {
-                parameter_types.push(param_type[1..].to_string());
+            if let Some(param_type) = raw_param.split(':').nth(1).and_then(|it| it.get(1..)) {
+                parameter_types.push(param_type.to_string());
             } else {
                 // The unwrap_or_else is useful when you have tuple
                 parameter_types.push(raw_param);
@@ -195,14 +197,23 @@ impl From<&'_ ast::FnDef> for FunctionSignature {
                     let raw_param = self_param.syntax().text().to_string();
 
                     res_types.push(
-                        raw_param.split(':').nth(1).unwrap_or_else(|| " Self")[1..].to_string(),
+                        raw_param
+                            .split(':')
+                            .nth(1)
+                            .and_then(|it| it.get(1..))
+                            .unwrap_or_else(|| "Self")
+                            .to_string(),
                     );
                     res.push(raw_param);
                 }
 
                 res.extend(param_list.params().map(|param| param.syntax().text().to_string()));
                 res_types.extend(param_list.params().map(|param| {
-                    param.syntax().text().to_string().split(':').nth(1).unwrap()[1..].to_string()
+                    let param_text = param.syntax().text().to_string();
+                    match param_text.split(':').nth(1).and_then(|it| it.get(1..)) {
+                        Some(it) => it.to_string(),
+                        None => param_text,
+                    }
                 }));
             }
             (has_self_param, res, res_types)
diff --git a/crates/ra_ide/src/display/navigation_target.rs b/crates/ra_ide/src/display/navigation_target.rs
index 914a8b471..5da28edd2 100644
--- a/crates/ra_ide/src/display/navigation_target.rs
+++ b/crates/ra_ide/src/display/navigation_target.rs
@@ -11,7 +11,7 @@ use ra_syntax::{
     TextRange,
 };
 
-use crate::FileSymbol;
+use crate::{FileRange, FileSymbol};
 
 use super::short_label::ShortLabel;
 
@@ -22,10 +22,11 @@ use super::short_label::ShortLabel;
 /// code, like a function or a struct, but this is not strictly required.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct NavigationTarget {
+    // FIXME: use FileRange?
     file_id: FileId,
+    full_range: TextRange,
     name: SmolStr,
     kind: SyntaxKind,
-    full_range: TextRange,
     focus_range: Option<TextRange>,
     container_name: Option<SmolStr>,
     description: Option<String>,
@@ -63,6 +64,10 @@ impl NavigationTarget {
         self.file_id
     }
 
+    pub fn file_range(&self) -> FileRange {
+        FileRange { file_id: self.file_id, range: self.full_range }
+    }
+
     pub fn full_range(&self) -> TextRange {
         self.full_range
     }
@@ -376,16 +381,20 @@ impl ToNav for hir::Local {
 impl ToNav for hir::TypeParam {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
-        let range = match src.value {
+        let full_range = match &src.value {
             Either::Left(it) => it.syntax().text_range(),
             Either::Right(it) => it.syntax().text_range(),
         };
+        let focus_range = match &src.value {
+            Either::Left(_) => None,
+            Either::Right(it) => it.name().map(|it| it.syntax().text_range()),
+        };
         NavigationTarget {
             file_id: src.file_id.original_file(db),
             name: self.name(db).to_string().into(),
             kind: TYPE_PARAM,
-            full_range: range,
-            focus_range: None,
+            full_range,
+            focus_range,
             container_name: None,
             description: None,
             docs: None,