ra_ide: refactor readonly String -> &str

crates/ra_ide/src/display.rs

@@ -6,6 +6,8 @@ mod navigation_target;
 mod structure;
 mod short_label;
 
+use std::fmt::{Display, Write};
+
 use ra_syntax::{
     ast::{self, AstNode, AttrsOwner, NameOwner, TypeParamsOwner},
     SyntaxKind::{ATTR, COMMENT},
@@ -67,24 +69,27 @@ pub(crate) fn macro_label(node: &ast::MacroCall) -> String {
     format!("{}macro_rules! {}", vis, name)
 }
 
-pub(crate) fn rust_code_markup<CODE: AsRef<str>>(val: CODE) -> String {
-    rust_code_markup_with_doc::<_, &str>(val, None, None)
+pub(crate) fn rust_code_markup(code: &impl Display) -> String {
+    rust_code_markup_with_doc(code, None, None)
 }
 
-pub(crate) fn rust_code_markup_with_doc<CODE, DOC>(
-    val: CODE,
-    doc: Option<DOC>,
-    mod_path: Option<String>,
-) -> String
-where
-    CODE: AsRef<str>,
-    DOC: AsRef<str>,
-{
-    let mod_path =
-        mod_path.filter(|path| !path.is_empty()).map(|path| path + "\n").unwrap_or_default();
-    if let Some(doc) = doc {
-        format!("```rust\n{}{}\n```\n\n{}", mod_path, val.as_ref(), doc.as_ref())
-    } else {
-        format!("```rust\n{}{}\n```", mod_path, val.as_ref())
+pub(crate) fn rust_code_markup_with_doc(
+    code: &impl Display,
+    doc: Option<&str>,
+    mod_path: Option<&str>,
+) -> String {
+    let mut markup = "```rust\n".to_owned();
+
+    if let Some(mod_path) = mod_path {
+        if !mod_path.is_empty() {
+            write!(markup, "{}\n", mod_path).unwrap();
+        }
     }
+    write!(markup, "{}\n```", code).unwrap();
+
+    if let Some(doc) = doc {
+        write!(markup, "\n\n{}", doc).unwrap();
+    }
+
+    markup
 }

crates/ra_ide/src/hover.rs

@@ -67,10 +67,10 @@ fn hover_text(
     desc: Option<String>,
     mod_path: Option<String>,
 ) -> Option<String> {
-    match (desc, docs, mod_path) {
-        (Some(desc), docs, mod_path) => Some(rust_code_markup_with_doc(desc, docs, mod_path)),
-        (None, Some(docs), _) => Some(docs),
-        _ => None,
+    if let Some(desc) = desc {
+        Some(rust_code_markup_with_doc(&desc, docs.as_deref(), mod_path.as_deref()))
+    } else {
+        docs
     }
 }
 
@@ -106,7 +106,7 @@ fn determine_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
             .flatten()
             .join("::")
     });
-    mod_path
+    mod_path // FIXME: replace dashes with underscores in crate display name
 }
 
 fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<String> {
@@ -143,9 +143,7 @@ fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<Strin
             ModuleDef::TypeAlias(it) => from_def_source(db, it, mod_path),
             ModuleDef::BuiltinType(it) => Some(it.to_string()),
         },
-        Definition::Local(it) => {
-            Some(rust_code_markup(it.ty(db).display_truncated(db, None).to_string()))
-        }
+        Definition::Local(it) => Some(rust_code_markup(&it.ty(db).display_truncated(db, None))),
         Definition::TypeParam(_) | Definition::SelfType(_) => {
             // FIXME: Hover for generic param
             None
@@ -210,7 +208,7 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
         }
     }?;
 
-    res.extend(Some(rust_code_markup(ty.display_truncated(db, None).to_string())));
+    res.extend(Some(rust_code_markup(&ty.display_truncated(db, None))));
     let range = sema.original_range(&node).range;
     Some(RangeInfo::new(range, res))
 }