improve names

src/main.rs

@@ -58,7 +58,7 @@ mod rover {
 mod driver {
     use super::rover;
 
-    fn perform_insn(command: &str, rover: &rover::Rover) -> rover::Rover {
+    fn perform_command(command: &str, rover: &rover::Rover) -> rover::Rover {
 	match command {
 	    "f" => rover::forward(&rover),
 	    "b" => rover::backward(&rover),
@@ -68,12 +68,12 @@ mod driver {
 	}
     }
 
-    pub fn execute(rover: &rover::Rover, instructions: &str) -> rover::Rover {
-	if instructions.is_empty() {
+    pub fn execute(rover: &rover::Rover, commands: &str) -> rover::Rover {
+	if commands.is_empty() {
 	    rover.clone()
 	} else {
-	    let (first, rest) = instructions.split_at(1);
-	    execute(&perform_insn(first, rover), rest)
+	    let (now, later) = commands.split_at(1);
+	    execute(&perform_command(now, rover), later)
 	}
     }
 }