fix clippy

src/machine/mod.rs

@@ -125,7 +125,7 @@ mod libraries {
     }
 
     pub(crate) fn get(name: &str) -> Option<&'static str> {
-        LIBRARIES.with(|libs| libs.get(name).map(|&lib| lib))
+        LIBRARIES.with(|libs| libs.get(name).copied())
     }
 
     #[cfg(test)]

src/machine/parsed_results.rs

@@ -38,7 +38,7 @@ pub fn write_prolog_value_as_json<W: Write>(
                 )
             } else {
                 //return valid json string
-                writer.write_str(&s)
+                writer.write_str(s)
             }
         }
         Value::List(l) => {