Move docs to dedicated module

crates/ra_hir/src/docs.rs

@@ -1,6 +1,6 @@
 use ra_syntax::ast;
 
-use crate::HirDatabase;
+use crate::{HirDatabase, Module, StructField, Struct, Enum, EnumVariant, Static, Const, Function, Union};
 
 /// Holds documentation
 #[derive(Debug, Clone)]
@@ -29,3 +29,72 @@ pub trait Docs {
 pub(crate) fn docs_from_ast(node: &impl ast::DocCommentsOwner) -> Option<Documentation> {
     node.doc_comment_text().map(|it| Documentation::new(&it))
 }
+
+impl Docs for Module {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        self.declaration_source(db).and_then(|it| docs_from_ast(&*it.1))
+    }
+}
+
+impl Docs for StructField {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        match self.source(db).1 {
+            FieldSource::Named(named) => docs_from_ast(&*named),
+            FieldSource::Pos(..) => return None,
+        }
+    }
+}
+
+impl Docs for Struct {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for Union {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for Enum {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for EnumVariant {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for Function {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for Const {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for Static {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for Trait {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}
+
+impl Docs for TypeAlias {
+    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
+        docs_from_ast(&*self.source(db).1)
+    }
+}