Make MultipartParserError Public

Sources/MultipartKit/MultipartParserError.swift

@@ -1,7 +1,25 @@
 /// Technical parsing error, such as malformed data or invalid characters.
 /// This is mainly used by ``MultipartParser``.
-package enum MultipartParserError: Swift.Error, Equatable {
-    case invalidBoundary
-    case invalidHeader(reason: String)
-    case invalidBody(reason: String)
+public struct MultipartParserError: Swift.Error, Equatable {
+
+    enum Base: Equatable {
+        case invalidBoundary
+        case invalidHeader(reason: String)
+        case invalidBody(reason: String)
+    }
+
+    let base: Base
+
+    private init(base: Base) {
+        self.base = base
+    }
+
+    public static let invalidBoundary = MultipartParserError(base: .invalidBoundary)
+
+    public static func invalidHeader(reason: String) -> MultipartParserError {
+        return MultipartParserError(base: .invalidHeader(reason: reason))
+    }
+    public static func invalidBody(reason: String) -> MultipartParserError {
+        return MultipartParserError(base: .invalidBody(reason: reason))    
+    }
 }