add rest package

errors.go

@@ -0,0 +1,30 @@
+package rest
+
+import "net/http"
+
+// Err is an empty error, representing any REST API Error.
+var Err = Error{}
+
+// ErrBadRequest represents HTTP 400 Bad Request.
+var ErrBadRequest = Error{
+	StatusCode: http.StatusBadRequest,
+	Message:    "Bad request",
+}
+
+// ErrInternalServerError represents HTTP 500 Internal Server Error.
+var ErrInternalServerError = Error{
+	StatusCode: http.StatusInternalServerError,
+	Message:    "Internal server error",
+}
+
+// ErrNotFound represents HTTP 404 Not Found.
+var ErrNotFound = Error{
+	StatusCode: http.StatusNotFound,
+	Message:    "Not found",
+}
+
+// ErrUnavailable represents HTTP 503 Service Unavailable.
+var ErrUnavailable = Error{
+	StatusCode: http.StatusServiceUnavailable,
+	Message:    "Service unavailable",
+}