Allowing generalized rules in typed symbols.

2 files changed, 40 insertions, 8 deletions

diff --git a/intf/extend.mli b/intf/extend.mli
index 57abdc38fb..e1520dec54 100644
--- a/intf/extend.mli
+++ b/intf/extend.mli
@@ -65,6 +65,17 @@ type user_symbol =
 
 (** {5 Type-safe grammar extension} *)
 
+(** (a, b, r) adj => [a = x₁ -> ... xₙ -> r] & [b = x₁ * (... (xₙ * unit))]. *)
+type (_, _, _) adj =
+| Adj0 : ('r, unit, 'r) adj
+| AdjS : ('s, 'b, 'r) adj -> ('a -> 's, 'a * 'b, 'r) adj
+
+type _ index =
+| I0 : 'a -> ('a * 'r) index
+| IS : 'a index -> ('b * 'a) index
+
+(** This type should be marshallable, this is why we use a convoluted
+    representation in the [Arules] constructor instead of putting a function. *)
 type ('self, 'a) symbol =
 | Atoken : Tok.t -> ('self, string) symbol
 | Alist1 : ('self, 'a) symbol -> ('self, 'a list) symbol
@@ -77,11 +88,19 @@ type ('self, 'a) symbol =
 | Anext : ('self, 'self) symbol
 | Aentry : 'a Entry.t -> ('self, 'a) symbol
 | Aentryl : 'a Entry.t * int -> ('self, 'a) symbol
+| Arules : 'a rules -> ('self, 'a index) symbol
 
-type ('self, _, 'r) rule =
+and ('self, _, 'r) rule =
 | Stop : ('self, 'r, 'r) rule
 | Next : ('self, 'a, 'r) rule * ('self, 'b) symbol -> ('self, 'b -> 'a, 'r) rule
 
+and 'a rules =
+| Rule0 : unit rules
+| RuleS :
+  ('any, 'act, Loc.t -> Loc.t * 'a) rule *
+  ('act, 'a, Loc.t -> Loc.t * 'a) adj *
+  'b rules -> ((Loc.t * 'a) * 'b) rules
+
 type 'a production_rule =
 | Rule : ('a, 'act, Loc.t -> 'a) rule * 'act -> 'a production_rule
 
diff --git a/parsing/pcoq.ml b/parsing/pcoq.ml
index dac5b3bfd8..91f933987b 100644
--- a/parsing/pcoq.ml
+++ b/parsing/pcoq.ml
@@ -671,6 +671,13 @@ let rec symbol_of_constr_prod_entry_key assoc from forpat typ =
 
 (** Binding general entry keys to symbol *)
 
+let tuplify l =
+  List.fold_left (fun accu x -> Obj.repr (x, accu)) (Obj.repr ()) l
+
+let rec adj : type a b c. (a, b, Loc.t -> Loc.t * c) adj -> _ = function
+| Adj0 -> Obj.magic (fun accu f loc -> f (Obj.repr (to_coqloc loc, tuplify accu)))
+| AdjS e -> Obj.magic (fun accu f x -> adj e (x :: accu) f)
+
 let rec symbol_of_prod_entry_key : type s a. (s, a) symbol -> _ = function
   | Atoken t -> Symbols.stoken t
   | Alist1 s -> Symbols.slist1 (symbol_of_prod_entry_key s)
@@ -695,21 +702,27 @@ let rec symbol_of_prod_entry_key : type s a. (s, a) symbol -> _ = function
   | Aentryl (e, n) ->
     let e = get_grammar e in
     Symbols.snterml (Gram.Entry.obj (weaken_entry e), string_of_int n)
+  | Arules rs -> Gram.srules' (symbol_of_rules rs [] (fun x -> I0 x))
 
-let level_of_snterml e = int_of_string (Symbols.snterml_level e)
-
-let rec of_coq_rule : type self a r. (self, a, r) Extend.rule -> _ = function
+and symbol_of_rule : type s a r. (s, a, r) Extend.rule -> _ = function
 | Stop -> fun accu -> accu
-| Next (r, tok) -> fun accu ->
-  let symb = symbol_of_prod_entry_key tok in
-  of_coq_rule r (symb :: accu)
+| Next (r, s) -> fun accu -> symbol_of_rule r (symbol_of_prod_entry_key s :: accu)
+
+and symbol_of_rules : type a. a Extend.rules -> _ = function
+| Rule0 -> fun accu _ -> accu
+| RuleS (r, e, rs) -> fun accu f ->
+  let symb = symbol_of_rule r [] in
+  let act = adj e [] f in
+  symbol_of_rules rs ((symb, act) :: accu) (fun x -> IS (f x))
+
+let level_of_snterml e = int_of_string (Symbols.snterml_level e)
 
 let rec of_coq_action : type a r. (r, a, Loc.t -> r) Extend.rule -> a -> Gram.action = function
 | Stop -> fun f -> Gram.action (fun loc -> f (to_coqloc loc))
 | Next (r, _) -> fun f -> Gram.action (fun x -> of_coq_action r (f x))
 
 let of_coq_production_rule : type a. a Extend.production_rule -> _ = function
-| Rule (toks, act) -> (of_coq_rule toks [], of_coq_action toks act)
+| Rule (toks, act) -> (symbol_of_rule toks [], of_coq_action toks act)
 
 let of_coq_single_extend_statement (lvl, assoc, rule) =
   (lvl, Option.map of_coq_assoc assoc, List.map of_coq_production_rule rule)