pub struct PatternError;

/// Error type returned by the matcher.
#[derive(Clone)]
pub enum MatchError {
    /// Returned if the pattern nests too deeply.
    StackOverflow,
    /// Returned if the pattern rejects the input.
    ValidationError,
    /// Returned if the pattern attempts an unsupported operation.
    ///
    /// In particular, if the PatternTypes doesn't support get or pairs for a
    /// given value, this error will be returned. It can be treated as a
    /// ValidationError, or as a bug in the pattern, at the user's discretion.
    UnsupportedOperation,
    /// Returned if an unspecified non-critical error occurred.
    Other
}