1 files changed, 14 insertions, 22 deletions

diff --git a/crates/ra_proc_macro_srv/src/lib.rs b/crates/ra_proc_macro_srv/src/lib.rs
index c62b0ed89..7faf36834 100644
--- a/crates/ra_proc_macro_srv/src/lib.rs
+++ b/crates/ra_proc_macro_srv/src/lib.rs
@@ -3,10 +3,10 @@
 //! This library is able to call compiled Rust custom derive dynamic libraries on arbitrary code.
 //! The general idea here is based on https://github.com/fedochet/rust-proc-macro-expander.
 //!
-//! But we change some several design for fitting RA needs:
+//! But we adapt it to better fit RA needs:
 //!
-//! * We use `ra_tt` for proc-macro `TokenStream` server, it is easy to manipute and interact with
-//!   RA then proc-macro2 token stream.
+//! * We use `ra_tt` for proc-macro `TokenStream` server, it is easy to manipulate and interact with
+//!   RA than `proc-macro2` token stream.
 //! * By **copying** the whole rustc `lib_proc_macro` code, we are able to build this with `stable`
 //!   rustc rather than `unstable`. (Although in gerenal ABI compatibility is still an issue)
 
@@ -21,36 +21,28 @@ mod dylib;
 
 use proc_macro::bridge::client::TokenStream;
 use ra_proc_macro::{ExpansionResult, ExpansionTask, ListMacrosResult, ListMacrosTask};
+use std::path::Path;
 
 pub(crate) fn expand_task(task: &ExpansionTask) -> Result<ExpansionResult, String> {
-    let expander = dylib::Expander::new(&task.lib)
-        .expect(&format!("Cannot expand with provided libraries: ${:?}", &task.lib));
+    let expander = create_expander(&task.lib);
 
     match expander.expand(&task.macro_name, &task.macro_body, task.attributes.as_ref()) {
         Ok(expansion) => Ok(ExpansionResult { expansion }),
         Err(msg) => {
-            let reason = format!(
-                "Cannot perform expansion for {}: error {:?}!",
-                &task.macro_name,
-                msg.as_str()
-            );
-            Err(reason)
+            Err(format!("Cannot perform expansion for {}: error {:?}", &task.macro_name, msg))
         }
     }
 }
 
-pub(crate) fn list_macros(task: &ListMacrosTask) -> Result<ListMacrosResult, String> {
-    let expander = dylib::Expander::new(&task.lib)
-        .expect(&format!("Cannot expand with provided libraries: ${:?}", &task.lib));
+pub(crate) fn list_macros(task: &ListMacrosTask) -> ListMacrosResult {
+    let expander = create_expander(&task.lib);
 
-    match expander.list_macros() {
-        Ok(macros) => Ok(ListMacrosResult { macros }),
-        Err(msg) => {
-            let reason =
-                format!("Cannot perform expansion for {:?}: error {:?}!", &task.lib, msg.as_str());
-            Err(reason)
-        }
-    }
+    ListMacrosResult { macros: expander.list_macros() }
+}
+
+fn create_expander(lib: &Path) -> dylib::Expander {
+    dylib::Expander::new(lib)
+        .unwrap_or_else(|err| panic!("Cannot create expander for {:?}: {:?}", lib, err))
 }
 
 pub mod cli;