Better error messages in parser

diff --git a/ocaml/parser.ml b/ocaml/parser.ml
index 6bcb70d909fd0b6117292aa2cdcb3b9a7d88da0f..34b62ba99aa3808b3f14c5084731350f1026ef80 100644 (file)
--- a/ocaml/parser.ml
+++ b/ocaml/parser.ml
@@ -18,7 +18,7 @@ let mk_var' (bound, free) x =
 ;;\r
 \r
 let mk_app' = function\r
-  | [] ->  raise (ParsingError "bug")\r
+  | [] ->  assert false\r
   | t :: ts -> List.fold_left mk_app t ts\r
 ;;\r
 \r
@@ -73,12 +73,12 @@ let rec read_smt vars =
       | Some varname, cs ->\r
       let vars' = (varname::bound, free) in\r
       (match strip_spaces cs with\r
-        | [] -> raise (ParsingError "manca dopo variabile lambda")\r
+        | [] -> raise (ParsingError "Lambda expression incomplete")\r
         | c::cs -> (if c = '.' then (match read_smt vars' cs with\r
-          | None, _, _ -> raise (ParsingError "manca corpo lambda")\r
+          | None, _, _ -> raise (ParsingError "Lambda body expected")\r
           | Some [x], y, (_, free) -> Some [mk_lam x], y, (bound, free)\r
-          | Some _, _, _ -> raise (ParsingError "???")\r
-          ) else raise (ParsingError "manca . nel lambda")\r
+          | Some _, _, _ -> assert false\r
+          ) else raise (ParsingError "Expected `.` after variable in lambda")\r
         ))\r
       | _, _ -> assert false\r
  ) in let rec aux vars cs =\r
@@ -96,7 +96,7 @@ let rec read_smt vars =
           | None, cs, vars -> Some [tm], cs, vars\r
           | Some ts, cs, vars -> Some (tm :: ts), cs, vars\r
         )\r
-      | Some _ -> raise (ParsingError "bug")\r
+      | Some _ -> assert false\r
       | None -> None, x, vars\r
   in fun cs -> match aux vars cs with\r
     | None, cs, vars -> None, cs, vars\r
@@ -108,20 +108,20 @@ and read_pars vars = function
     let cs = strip_spaces cs in\r
     match cs with\r
       | [] -> None, [], vars\r
-      | c::cs -> if c = ')' then tm, cs, vars else raise (ParsingError ") mancante")\r
-    ) else raise (ParsingError "???")\r
+      | c::cs -> if c = ')' then tm, cs, vars else raise (ParsingError "Missing `)`")\r
+    ) else assert false\r
 ;;\r
 \r
 let parse x =\r
   match read_smt ([],[]) (explode x) with\r
   | Some [y], [], _ -> y\r
-  | _, _, _ -> raise (ParsingError "???")\r
+  | _, _, _ -> assert false\r
 ;;\r
 \r
 let parse_many strs =\r
   let f (x, y) z = match read_smt y (explode z) with\r
   | Some[tm], [], vars -> (tm :: x, vars)\r
-  | _, _, _ -> raise (ParsingError "???")\r
+  | _, _, _ -> assert false\r
   in let aux = List.fold_left f ([], ([], [])) (* index zero is reserved *)\r
   in let (tms, (_, free)) = aux strs\r
   in (List.rev tms, free)\r
@@ -169,7 +169,7 @@ let problem_of_string s =
  let strs = [div] @ ps @ conv in\r
 \r
  if List.length ps = 0 && List.length conv = 0\r
-  then raise (ParsingError "empty problem");\r
+  then raise (ParsingError "Parsed empty problem");\r
 \r
  (* parse' *)\r
  let (tms, free) = parse_many strs in\r
@@ -187,6 +187,7 @@ let problem_of_string s =
  let open Num in\r
  let exclude_bottom = function\r
  | #nf_nob as t -> t\r
+ (* actually, the following may be assert false *)\r
  | `Bottom -> raise (ParsingError "Input term not in normal form") in\r
  let rec aux_nob lev : nf_nob -> nf = function\r
  | `I((n,_), args) -> `I((n,(if lev = 0 then 0 else 1) + Listx.length args), Listx.map (fun t -> exclude_bottom (aux_nob lev t)) args)\r
@@ -206,17 +207,17 @@ let div = if not div_provided || div = `Bottom
  then None\r
  else match div with\r
   | `I _ as t -> Some t\r
-  | _ -> raise (ParsingError "div is not an inert or BOT in the initial problem") in\r
+  | _ -> raise (ParsingError "D is not an inert in the initial problem") in\r
 let conv = Util.filter_map (\r
  function\r
  | #i_n_var as t -> Some t\r
  | `Lam _ -> None\r
- | _ -> raise (ParsingError "A term in conv is not i_n_var")\r
+ | _ -> raise (ParsingError "A C-term is not i_n_var")\r
  ) conv in\r
 let ps = List.map (\r
  function\r
   | #i_n_var as y -> y\r
-  | _ as y -> raise (ParsingError ("A term in num is not i_n_var" ^ Num.string_of_nf y))\r
+  | _ -> raise (ParsingError "An N-term is not i_n_var")\r
  ) ps in\r
  name, div, conv, ps, free\r
 ;;\r