refactor: rewrite error messages

src/error.rs

@@ -14,35 +14,33 @@ pub enum ParseLevelError {
     /// There is no map data.
     #[error("no map data")]
     NoMap,
-    /// There is an error when parsing the map.
+    /// An error occurred while parsing the map.
     #[error(transparent)]
     ParseMapError(#[from] ParseMapError),
 }
 
 /// An error which can be returned when parsing a map.
 #[derive(Error, Clone, Eq, PartialEq, Debug)]
 pub enum ParseMapError {
-    /// There are no players. There should be only one player.
+    /// There is no player. There should be exactly one player.
     #[error("no player")]
     NoPlayer,
-    /// There are multiple players. There should only be one player.
+    /// There are multiple players. There should be exactly one player.
     #[error("more than one player")]
     MoreThanOnePlayer,
-    /// The number of boxes and targets are inconsistent. They should be
-    /// consistent.
+    /// The number of boxes and goals do not match. They should be equal.
     #[error("mismatch between number of boxes and goals")]
     BoxGoalMismatch,
-    /// There are no boxes or goals. There should be at least one box and one
-    /// goal.
+    /// There are no boxes or goals. There should be at least one box and one goal.
     #[error("no box or goal")]
     NoBoxOrGoal,
     /// Contains non-XSB format character.
     #[error("invalid character: `{0}`")]
     InvalidCharacter(char),
-    /// RLE decoding error occurred.
+    /// An error occurred during RLE decoding.
     #[error(transparent)]
     DecodeRleError(#[from] DecodeRleError),
-    /// Actions are invalid and cannot be used to build and create levels.
+    /// Actions are invalid and cannot be used to create level.
     #[error("invalid actions")]
     InvalidActions,
 }
@@ -58,9 +56,9 @@ pub enum ParseActionError {
 /// An error which can be returned when encoding RLE.
 #[derive(Error, Clone, Eq, PartialEq, Debug)]
 pub enum EncodeRleError {
-    /// Unencodable characters encountered, such as numbers.
-    #[error("invalid character: `{0}`")]
-    InvalidCharacter(char),
+    /// Encountered an unencodable numeric character.
+    #[error("numeric character encountered: `{0}`")]
+    NumericCharacter(char),
 }
 
 /// An error which can be returned when decoding RLE.
@@ -88,10 +86,10 @@ pub enum ActionError {
     /// Push in the specified direction is blocked.
     #[error("push in the specified direction is blocked")]
     PushBlocked,
-    /// No actions.
+    /// No actions available.
     #[error("no actions")]
     NoActions,
-    /// No undone actions.
+    /// No undone actions available.
     #[error("no undone actions")]
     NoUndoneActions,
 }

src/run_length.rs

@@ -23,7 +23,7 @@ pub fn rle_encode(str: &str) -> Result<String, EncodeRleError> {
     let mut count = 0;
     while let Some(char) = chars.next() {
         if char.is_numeric() {
-            return Err(EncodeRleError::InvalidCharacter(char));
+            return Err(EncodeRleError::NumericCharacter(char));
         }
         count += 1;
         if chars.peek() != Some(&char) {

tests/run_length.rs

@@ -14,7 +14,7 @@ fn test_rle_encode_single_char() {
 fn test_rle_encode_invalid_char() {
     assert_eq!(
         rle_encode("aa2bb").unwrap_err(),
-        EncodeRleError::InvalidCharacter('2')
+        EncodeRleError::NumericCharacter('2')
     );
 }