New Server & Manipulation refactor

Co-authored-by: Estevan Castilho <tevo@riajuu.net>

1 files changed, 34 insertions, 0 deletions

diff --git a/lib/error.ml b/lib/error.ml
new file mode 100644
index 0000000..edaa85b
--- /dev/null
+++ b/lib/error.ml
@@ -0,0 +1,34 @@
+
+(** Error types for manipulation operations *)
+type t =
+  | RelationNotFound of string
+  | RelationAlreadyExists of string
+  | TupleNotFound of Conventions.Hash.t
+  | DuplicateTuple of Conventions.Hash.t
+  | ConstraintViolation of string
+  | StorageError of string
+  | UnrecognizedSublanguage of string
+  | MalformedExpression of Sexplib.Sexp.t
+  (* TODO: think of a better way to manage and serialize sublanguage errors *)
+  | SublanguageError of Sexplib.Sexp.t
+  | Conflict of { old_db : Management.Database.t; new_db : Management.Database.t}
+  | SyntaxError of string
+
+let sexp_of_error e =
+  let open Sexplib.Sexp in
+  let error e ps = List (Atom e :: ps) in
+  let (<+>) key value = List [Atom key; value] in
+  match e with
+  (* TODO: think of a subset of common attributes that every error should have (message, etc)? *)
+  | RelationNotFound s          -> error "relation-not-found"       ["relation"   <+> (Atom s)]
+  | RelationAlreadyExists s     -> error "relation-already-exists"  ["relation"   <+> (Atom s)]
+  | TupleNotFound h             -> error "tuple-not-found"          ["hash"       <+> (Atom h)]
+  | DuplicateTuple h            -> error "duplicate-tuple"          ["hash"       <+> (Atom h)]
+  | ConstraintViolation s       -> error "constraint-violation"     ["message"    <+> (Atom s)]
+  | StorageError s              -> error "storage-error"            ["message"    <+> (Atom s)]
+  | UnrecognizedSublanguage s   -> error "unrecognized-sublanguage" ["tag"        <+> (Atom s)]
+  | MalformedExpression s       -> error "malformed-expression"     ["expression" <+> s]
+  | SublanguageError s          -> error "sublanguage-error"        ["error"      <+> s]
+  | SyntaxError s               -> error "syntax-error"             ["message"    <+> (Atom s)]
+  | Conflict { old_db; new_db } -> error "conflict"                 ["old-hash"   <+> (Atom old_db.hash);
+                                                                     "new-hash"   <+> (Atom new_db.hash)]