Add const type inference

crates/ra_hir/src/code_model_impl/konst.rs

@@ -0,0 +1,26 @@
+use std::sync::Arc;
+
+use ra_syntax::ast::{NameOwner};
+
+use crate::{
+    Name, AsName, Const, ConstSignature,
+    type_ref::{TypeRef},
+    PersistentHirDatabase,
+};
+
+impl ConstSignature {
+    pub(crate) fn const_signature_query(
+        db: &impl PersistentHirDatabase,
+        konst: Const,
+    ) -> Arc<ConstSignature> {
+        let (_, node) = konst.source(db);
+
+        let name = node.name().map(|n| n.as_name()).unwrap_or_else(Name::missing);
+
+        let type_ref = TypeRef::from_ast_opt(node.type_ref());
+
+        let sig = ConstSignature { name, type_ref };
+
+        Arc::new(sig)
+    }
+}