Added PatterErrorKind enum + thiserror dependency

Author: Dym03

Cargo.toml

@@ -15,3 +15,6 @@ rust-version = "1.63.0"
 [dev-dependencies]
 tempfile = "3"
 doc-comment = "0.3"
+
+[dependencies]
+thiserror = "2.0.17"

src/lib.rs

@@ -500,14 +500,23 @@ pub struct PatternError {
     /// The approximate character index of where the error occurred.
     pub pos: usize,
 
-    /// A message describing the error.
-    pub msg: &'static str,
+    /// Specific kind of pattern error.
+    pub msg: PatternErrorKind,
 }
 
-impl Error for PatternError {
-    fn description(&self) -> &str {
-        self.msg
-    }
+/// Define kinds of Error that can happen during parsing Pattern
+#[derive(Debug, PartialEq, Eq, Clone, Copy, thiserror::Error)]
+#[non_exhaustive]
+pub enum PatternErrorKind {
+    /// Wildcard should be only `*` or `**`
+    #[error("wildcards are either regular `*` or recursive `**`")]
+    InvalidWildcards,
+    /// Recursive wildcard should be in `**/` | `a/**/b` | `a/**` structure
+    #[error("recursive wildcards must form a single path component")]
+    InvalidRecursiveWildcards,
+    /// Range pattern should be enclosed by `[]`
+    #[error("invalid range pattern")]
+    InvalidRange
 }
 
 impl fmt::Display for PatternError {
@@ -597,11 +606,6 @@ enum MatchResult {
     EntirePatternDoesntMatch,
 }
 
-const ERROR_WILDCARDS: &str = "wildcards are either regular `*` or recursive `**`";
-const ERROR_RECURSIVE_WILDCARDS: &str = "recursive wildcards must form a single path \
-                                         component";
-const ERROR_INVALID_RANGE: &str = "invalid range pattern";
-
 impl Pattern {
     /// This function compiles Unix shell style patterns.
     ///
@@ -635,7 +639,7 @@ impl Pattern {
                         Ordering::Greater => {
                             return Err(PatternError {
                                 pos: old + 2,
-                                msg: ERROR_WILDCARDS,
+                                msg: PatternErrorKind::InvalidWildcards,
                             })
                         }
                         Ordering::Equal => {
@@ -655,14 +659,14 @@ impl Pattern {
                                 } else {
                                     return Err(PatternError {
                                         pos: i,
-                                        msg: ERROR_RECURSIVE_WILDCARDS,
+                                        msg: PatternErrorKind::InvalidRecursiveWildcards,
                                     });
                                 }
                             // `**` begins with non-separator
                             } else {
                                 return Err(PatternError {
                                     pos: old - 1,
-                                    msg: ERROR_RECURSIVE_WILDCARDS,
+                                    msg: PatternErrorKind::InvalidRecursiveWildcards,
                                 });
                             };
 
@@ -712,7 +716,7 @@ impl Pattern {
                     // if we get here then this is not a valid range pattern
                     return Err(PatternError {
                         pos: i,
-                        msg: ERROR_INVALID_RANGE,
+                        msg: PatternErrorKind::InvalidRange,
                     });
                 }
                 c => {