Add poc files

h_program-lang/errors_code.mli

@@ -0,0 +1,55 @@
+
+type error = {
+  typ: error_kind;
+  loc: Parse_info.token_location;
+  sev: severity;
+}
+ and severity = Fatal | Warning
+
+ and error_kind =
+ | Deadcode of entity
+ | UndefinedDefOfDecl of entity
+ | UnusedExport of entity * Common.filename
+ | UnusedVariable of string * Scope_code.scope
+
+ and entity = (string * Entity_code.entity_kind)
+
+
+(* @xxx to acknowledge or explain false positives *)
+type annotation =
+  | AtScheck of string
+
+(* to detect false positives (we use the Hashtbl.find_all property) *)
+type identifier_index = (string, Parse_info.token_location) Hashtbl.t
+
+
+val string_of_error: error -> string
+val string_of_error_kind: error_kind -> string
+
+
+val g_errors: error list ref
+(* !modify g_errors! *)
+val fatal: Parse_info.token_location -> error_kind -> unit
+val warning: Parse_info.token_location -> error_kind -> unit
+
+type rank =
+ | Never
+ | OnlyStrict
+ | Less
+ | Ok
+ | Important
+ | ReallyImportant
+
+val score_of_rank: 
+  rank -> int
+val rank_of_error:
+  error -> rank
+val score_of_error:
+  error -> int
+
+val annotation_at:
+  Parse_info.token_location -> annotation option
+
+(* have some approximations and Fps in graph_code_checker so filter them *)
+val adjust_errors:
+  error list -> error list