Slight refactor of REPL code

In preparation for multi-line REPL input

schala-repl/src/repl/mod.rs

@@ -33,7 +33,7 @@ impl Repl {
       languages,
       current_language_index,
       interpreter_directive_sigil: ':',
-      line_reader
+      line_reader,
     }
   }
 
@@ -90,16 +90,7 @@ impl Repl {
         },
         Ok(ReadResult::Eof) => break,
         Ok(ReadResult::Signal(_)) => break,
-        Ok(ReadResult::Input(ref input)) => {
-          self.line_reader.add_history_unique(input.to_string());
-          let output = match input.chars().nth(0) {
-            Some(ch) if ch == self.interpreter_directive_sigil => self.handle_interpreter_directive(input),
-            _ => Some(self.input_handler(input)),
-          };
-          if let Some(o) = output {
-            println!("=> {}", o);
-          }
-        }
+        Ok(ReadResult::Input(input)) => self.input_loop(input),
       }
     }
     self.line_reader.save_history(HISTORY_SAVE_FILE).unwrap_or(());
@@ -107,6 +98,23 @@ impl Repl {
     println!("Exiting...");
   }
 
+  fn input_loop(&mut self, input: String) {
+    if input == "" {
+      return;
+    }
+
+    if input.chars().nth(0).unwrap() == self.interpreter_directive_sigil {
+      if let Some(output) = self.handle_interpreter_directive(&input) {
+        println!("{}", output);
+      }
+      return;
+    } 
+
+    let output = self.input_handler(&input);
+    self.line_reader.add_history_unique(input.clone());
+    println!("=> {}", output);
+  }
+
   fn input_handler(&mut self, input: &str) -> String {
     let ref mut language = self.languages[self.current_language_index];
     let interpreter_output = language.execute_pipeline(input, &self.options);