improve attachment struct names and use attachment type constants

attachment_detail_struct.go

@@ -1,22 +1,24 @@
 package berr
 
-type detail struct {
+const AttachmentDetailType = "detail"
+
+type detailAttachment struct {
 	key   string
 	value any
 }
 
-func (d detail) Key() string {
+func (d detailAttachment) Key() string {
 	return d.key
 }
 
-func (d detail) Value() any {
+func (d detailAttachment) Value() any {
 	return d.value
 }
 
-func (d detail) Type() string {
-	return "berr_detail"
+func (d detailAttachment) Type() string {
+	return AttachmentDetailType
 }
 
-func (d detail) Sensitive() bool {
+func (d detailAttachment) Sensitive() bool {
 	return false
 }

attachment_error_struct.go

@@ -1,22 +1,24 @@
 package berr
 
-type errorDetail struct {
+const AttachmentErrorType = "error"
+
+type errorAttachment struct {
 	key   string
 	value error
 }
 
-func (d errorDetail) Key() string {
+func (d errorAttachment) Key() string {
 	return d.key
 }
 
-func (d errorDetail) Value() any {
+func (d errorAttachment) Value() any {
 	return d.value
 }
 
-func (d errorDetail) Type() string {
-	return "berr_error_detail"
+func (d errorAttachment) Type() string {
+	return AttachmentErrorType
 }
 
-func (d errorDetail) Sensitive() bool {
+func (d errorAttachment) Sensitive() bool {
 	return true
 }

attachment_metadata_struct.go

@@ -1,22 +1,24 @@
 package berr
 
-type metadataDetail struct {
+const AttachmentMetadataType = "metadata"
+
+type metadataAttachment struct {
 	key   string
 	value any
 }
 
-func (d metadataDetail) Key() string {
+func (d metadataAttachment) Key() string {
 	return d.key
 }
 
-func (d metadataDetail) Value() any {
+func (d metadataAttachment) Value() any {
 	return d.value
 }
 
-func (d metadataDetail) Type() string {
+func (d metadataAttachment) Type() string {
 	return "berr_metadata_detail"
 }
 
-func (d metadataDetail) Sensitive() bool {
+func (d metadataAttachment) Sensitive() bool {
 	return true
 }

error_struct.go

@@ -11,9 +11,9 @@ func newBerr(errorType ErrorType, errorMessage string, attachments ...Attachment
 	var next error
 
 	for _, d := range attachments {
-		if d.Type() == "berr_error_detail" && next == nil {
+		if d.Type() == AttachmentErrorType && next == nil {
 			next, _ = d.Value().(error)
-		} else if d.Type() == "berr_error_detail" {
+		} else if d.Type() == AttachmentErrorType {
 			next = fmt.Errorf("%s: %w", next, d.Value().(error))
 		} else if d.Type() == "berr_metadata_detail" {
 			errorMetadata[d.Key()] = d.Value()

functions.go

@@ -43,23 +43,23 @@ func Timeout(message string, attachments ...Attachment) Error {
 }
 
 func Detail(key string, value any) Attachment {
-	return detail{key: key, value: value}
+	return detailAttachment{key: key, value: value}
 }
 
 func D(key string, value any) Attachment {
 	return Detail(key, value)
 }
 
 func Metadata(key string, value any) Attachment {
-	return metadataDetail{key: key, value: value}
+	return metadataAttachment{key: key, value: value}
 }
 
 func M(key string, value any) Attachment {
 	return Metadata(key, value)
 }
 
 func Err(value error) Attachment {
-	return errorDetail{key: "error", value: value}
+	return errorAttachment{key: "error", value: value}
 }
 
 func E(value error) Attachment {