src/prepend_prefix.rs in faster_path-0.3.7 vs src/prepend_prefix.rs in faster_path-0.3.8

@@ -1,18 +1,19 @@
+use std::borrow::Cow;
 use dirname::dirname;
-use basename::basename;
-use std::path::MAIN_SEPARATOR as SEP;
+use path_parsing::{SEP, contains_sep};
+use std::path::MAIN_SEPARATOR;
 
-pub fn prepend_prefix(prefix: &str, relpath: &str) -> String {
-  let mut prefix: String = prefix.to_string();
+pub fn prepend_prefix<'a>(prefix: &'a str, relpath: &str) -> Cow<'a, str> {
   if relpath.is_empty() {
-    dirname(&prefix).to_string()
-  } else if prefix.contains(&SEP.to_string()[..]) {
-    prefix = dirname(&prefix).to_string();
-    if basename(&format!("{}{}", &prefix, "a"), "") != "a" {
-      prefix = format!("{}{}", prefix, &SEP);
+    dirname(prefix).into()
+  } else if contains_sep(prefix.as_bytes()) {
+    let prefix_dirname = dirname(prefix);
+    match prefix_dirname.as_bytes().last() {
+      None => relpath.to_string().into(),
+      Some(&SEP) => format!("{}{}", prefix_dirname, relpath).into(),
+      _ => format!("{}{}{}", prefix_dirname, MAIN_SEPARATOR, relpath).into()
     }
-    format!("{}{}", prefix, relpath)
   } else {
-    format!("{}{}", prefix, relpath)
+    format!("{}{}", prefix, relpath).into()
   }
 }