Use a common trait (TryFrom)

diff --git a/src/day17.rs b/src/day17.rs
index c64ed0e..f120506 100644 (file)
--- a/src/day17.rs
+++ b/src/day17.rs
@@ -1,17 +1,20 @@
 use super::intcode;\r
 use std::collections::HashSet;\r
+use std::convert::TryFrom;\r
 \r
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]\r
 enum Direction { Up, Left, Down, Right }\r
 \r
-impl Direction {\r
-    fn from_char(c: char) -> Option<Self> {\r
+impl TryFrom<char> for Direction {\r
+    type Error = ();\r
+\r
+    fn try_from(c: char) -> Result<Self, ()> {\r
         match c {\r
-            '^' => Some(Direction::Up),\r
-            '<' => Some(Direction::Left),\r
-            'v' => Some(Direction::Down),\r
-            '>' => Some(Direction::Right),\r
-             _  => None\r
+            '^' => Ok(Direction::Up),\r
+            '<' => Ok(Direction::Left),\r
+            'v' => Ok(Direction::Down),\r
+            '>' => Ok(Direction::Right),\r
+             _  => Err(())\r
         }\r
     }\r
 }\r
@@ -66,7 +69,7 @@ impl RobotTrackingSystem {
                 current_x = 0;\r
             } else {\r
                 let c = (*c as u8) as char;\r
-                if let Some(dir) =  Direction::from_char(c) {\r
+                if let Ok(dir) =  Direction::try_from(c) {\r
                     self.start_position = (current_x, self.board.len() as i32);\r
                     self.start_dir = dir\r
                 }\r