1 files changed, 92 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/display/short_label.rs b/crates/ra_ide_api/src/display/short_label.rs
new file mode 100644
index 000000000..6acb2ab92
--- /dev/null
+++ b/crates/ra_ide_api/src/display/short_label.rs
@@ -0,0 +1,92 @@
+use ra_syntax::{
+    ast::{self, NameOwner, VisibilityOwner, TypeAscriptionOwner, AstNode},
+};
+
+pub(crate) trait ShortLabel {
+    fn short_label(&self) -> Option<String>;
+}
+
+impl ShortLabel for ast::FnDef {
+    fn short_label(&self) -> Option<String> {
+        Some(crate::display::function_label(self))
+    }
+}
+
+impl ShortLabel for ast::StructDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "struct ")
+    }
+}
+
+impl ShortLabel for ast::EnumDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "enum ")
+    }
+}
+
+impl ShortLabel for ast::TraitDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "trait ")
+    }
+}
+
+impl ShortLabel for ast::Module {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "mod ")
+    }
+}
+
+impl ShortLabel for ast::TypeAliasDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "type ")
+    }
+}
+
+impl ShortLabel for ast::ConstDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_ascribed_node(self, "const ")
+    }
+}
+
+impl ShortLabel for ast::StaticDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_ascribed_node(self, "static ")
+    }
+}
+
+impl ShortLabel for ast::NamedFieldDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_ascribed_node(self, "")
+    }
+}
+
+impl ShortLabel for ast::EnumVariant {
+    fn short_label(&self) -> Option<String> {
+        Some(self.name()?.text().to_string())
+    }
+}
+
+fn short_label_from_ascribed_node<T>(node: &T, prefix: &str) -> Option<String>
+where
+    T: NameOwner + VisibilityOwner + TypeAscriptionOwner,
+{
+    let mut string = short_label_from_node(node, prefix)?;
+
+    if let Some(type_ref) = node.ascribed_type() {
+        string.push_str(": ");
+        type_ref.syntax().text().push_to(&mut string);
+    }
+
+    Some(string)
+}
+
+fn short_label_from_node<T>(node: &T, label: &str) -> Option<String>
+where
+    T: NameOwner + VisibilityOwner,
+{
+    let mut string =
+        node.visibility().map(|v| format!("{} ", v.syntax().text())).unwrap_or_default();
+    string.push_str(label);
+    string.push_str(node.name()?.text().as_str());
+    Some(string)
+}