Update

2 files changed, 589 insertions, 130 deletions

diff --git a/src/lib/repr/telcontar.ml b/src/lib/repr/telcontar.ml
new file mode 100644
index 0000000..ef55f37
--- /dev/null
+++ b/src/lib/repr/telcontar.ml
@@ -0,0 +1,355 @@
+(** Glyph position for the diacritc *)
+type position =
+  | Pos1
+  | Pos2
+  | Pos3
+  | Pos4
+
+(** Consonant category *)
+type category =
+  | I
+  | II
+  | III
+
+type voyel =
+  { opened : bool
+  ; position : [`Above | `Below ]
+  ; repr : string }
+
+type consonant =
+  { position : position
+  ; muted: string option
+  ; repr : string
+  ; primary : bool
+  ; category : category }
+
+
+type nasal = (t -> string)
+
+and t =
+  | Consonant of consonant
+  | Voyel of voyel
+  | Nasal of nasal
+  | Repr of string
+  | Nothing
+
+let none = Nothing
+
+let space s = Repr s
+
+let a = Voyel
+    { opened = true
+    ; position = `Above
+    ; repr = ""
+    }
+
+
+let app_e = function
+  | Pos1 -> "$"
+  | Pos2 -> "R"
+  | Pos3 -> "F"
+  | Pos4 -> "V"
+
+and app_eu = function
+  | Pos1 -> "Ü"
+  | Pos2 -> "Ý"
+  | Pos3 -> "Þ"
+  | Pos4 -> "ß"
+
+let e_opened = Voyel { opened = true ; position = `Above ; repr = "" }
+and e_closed = Voyel { opened = false; position = `Above ; repr = ""  }
+and schwa = Voyel
+    { opened = true
+    ; position = `Below
+    ; repr = "" }
+
+and eu_opened = Voyel { opened = true  ; position = `Above ; repr = "" }
+and eu_closed = Voyel { opened = false ; position = `Above ; repr = "" }
+
+and o = Voyel
+    { opened = true
+    ; position = `Above
+    ; repr = "" }
+
+and i = Voyel
+    { opened = true
+    ; position = `Above
+    ; repr =  "" }
+
+and y = Voyel
+    { opened = true
+    ; position = `Above
+    ; repr = "" }
+
+and u = Voyel
+    { opened = true
+    ; position = `Above
+    ; repr = "" }
+
+let p = Consonant
+    { position = Pos2
+    ; muted = Some ""
+    ; category = II
+    ; primary = true
+    ; repr = "" }
+
+and b = Consonant
+    { position = Pos1
+    ; muted = Some ""
+    ; category = II
+    ; primary = true
+    ; repr = "" }
+
+and t = Consonant
+    { position = Pos2
+    ; muted = Some ""
+    ; category = I
+    ; primary = true
+    ; repr = "" }
+
+and d = Consonant
+    { position = Pos1
+    ; muted = Some ""
+    ; category = I
+    ; primary = true
+    ; repr = "" }
+
+and k = Consonant
+    { position = Pos3
+    ; muted = Some "h"
+    ; category = III
+    ; primary = true
+    ; repr = "a" }
+
+and g = Consonant
+    { position = Pos1
+    ; muted = Some "h"
+    ; category = III
+    ; primary = true
+    ; repr = "s" }
+
+and f = Consonant
+    { position = Pos3
+    ; muted = None
+    ; category = II
+    ; primary = true
+    ; repr = "e" }
+
+and v = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = II
+    ; primary = true
+    ; repr = "r" }
+
+and ch = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = III
+    ; primary = true
+    ; repr = "d" }
+
+and j = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = III
+    ; primary = true
+    ; repr = "f" }
+
+and s = Consonant
+    { position = Pos4
+    ; muted = Some "i"
+    ; category = I
+    ; primary = true
+    ; repr = "3" }
+
+and z = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = I
+    ; primary = true
+    ; repr = "4" }
+
+and m = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = II
+    ; primary = true
+    ; repr = "t" }
+
+and n = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = I
+    ; primary = true
+    ; repr = "5" }
+
+and gn = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = III
+    ; primary = false
+    ; repr = "b" }
+
+and l = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = II
+    ; primary = false
+    ; repr = "j" }
+
+and r = Consonant
+    { position = Pos2
+    ; muted = None
+    ; category = I
+    ; primary = false
+    ; repr = "7" }
+
+let nasal v =
+  let Voyel letter = v [@@warning "-8"] in
+  Nasal
+    ( fun f ->
+        let Consonant c = m [@@warning "-8"] in
+        let default = c.repr ^ letter.repr in
+
+        match f with
+        | Consonant c -> begin match c.category with
+            | I -> default
+            | II ->
+              let Consonant c = n [@@warning "-8"] in
+              c.repr ^ letter.repr
+            | III ->
+              let Consonant c = gn [@@warning "-8"] in
+              c.repr ^ letter.repr
+          end
+        | _ -> default
+    )
+
+let a_nasal = nasal a
+and o_nasal = nasal o
+and i_nasal = nasal i
+and y_nasal = nasal y
+
+and semi_voyel_w = Consonant
+    { position = Pos3
+    ; muted = None
+    ; category = II
+    ; primary = false
+    ; repr = "." }
+
+and semi_voyel_y = Consonant
+    { position = Pos1
+    ; muted = None
+    ; category = II
+    ; primary = false
+    ; repr = "l" }
+
+and semi_voyel_u = Consonant
+    { position = Pos2
+    ; muted = None
+    ; category = II
+    ; primary = false
+    ; repr = "]" }
+
+  (*
+let diphtongue
+  : t -> t -> t
+  = fun t1 t2 -> match t1, t2 with
+    (*
+    | Consonant _, Voyel _ when t1 = semi_voyel_y && t2 = schwa ->
+      Consonant
+        { position = Pos1
+        ; muted = None
+        ; category = II
+        ; primary = false
+        ; repr = "m"}
+        *)
+    | Consonant c, Voyel v ->
+      Repr(c.repr ^ (v.app c.position))
+    | Consonant c, Nasal n ->
+      Repr(c.repr ^ (n none))
+    | _ ->
+      print_endline "Ignoring diphtongue";
+      none
+
+let muted
+  : t -> t
+  = fun t ->
+    match t with
+    | Consonant c ->
+      begin match c.muted with
+        | None -> t
+        | Some s -> Consonant {c with repr = s}
+      end
+    | _ -> t
+
+
+and portant =
+  { position = Pos4
+  ; muted = None
+  ; category = III
+  ; primary = false
+  ; repr = "`" }
+
+let fold
+  : t list -> string
+  = fun elems ->
+    let buff = Buffer.create 16 in
+
+    let rec _fold
+      = fun init -> function
+        | [] ->
+          begin match init with
+            | None
+            | Some Nothing
+              -> ()
+            | Some Voyel ( {position = `Above; _ } as v) ->
+              Buffer.add_string buff ("`" ^ (v.app portant.position))
+            | Some Voyel ( {position = `Below; _ } as v) ->
+              Buffer.add_string buff (v.app Pos1)
+            | Some Nasal n ->
+              Buffer.add_string buff ("`" ^ (n (Consonant portant)))
+            | Some Repr r ->
+              Buffer.add_string buff r
+            | Some Consonant c ->
+              Buffer.add_string buff (c.repr)
+          end
+        | hd::tl ->
+          match init, hd with
+          | Some Nothing, _ -> _fold (Some hd) tl
+          | _, Nothing      -> _fold init tl
+          | Some Voyel ({position = `Above; _} as v), Consonant c ->
+            Buffer.add_string buff (c.repr ^ (v.app c.position));
+            _fold None tl
+          | Some Voyel ({position = `Below; _} as v), Consonant c ->
+            Buffer.add_string buff ((v.app Pos1)^ c.repr);
+            _fold None tl
+          | Some Nasal n, Consonant c ->
+            Buffer.add_string buff (c.repr ^ (n hd));
+            _fold None tl
+          | Some Voyel v, _ ->
+            Buffer.add_string buff ("`" ^ (v.app portant.position));
+            _fold (Some hd) tl
+          | Some Nasal n, _ ->
+            Buffer.add_string buff ("`" ^ (n (Consonant portant)));
+            _fold (Some hd) tl
+          | Some Repr r, _ ->
+            Buffer.add_string buff r;
+            _fold (Some hd) tl
+          | Some Consonant c, _ ->
+            Buffer.add_string buff c.repr;
+            _fold (Some hd) tl
+
+          | None, Consonant c ->
+            Buffer.add_string buff c.repr;
+            _fold None tl
+          | None, Repr r ->
+            Buffer.add_string buff r;
+            _fold None tl
+          | None, Voyel _
+          | None, Nasal _ -> _fold (Some hd) tl
+
+    in
+    _fold None elems;
+    Buffer.contents buff
+    *)
diff --git a/src/lib/repr/tengwar.ml b/src/lib/repr/tengwar.ml
index d291a8b..1f34928 100644
--- a/src/lib/repr/tengwar.ml
+++ b/src/lib/repr/tengwar.ml
@@ -1,9 +1,15 @@
+type position_type =
+  [ `Above
+  | `Below ]
+
 (** Glyph position for the diacritc *)
 type position =
   | Pos1
   | Pos2
   | Pos3
   | Pos4
+  | Lower1
+  | Lower2
 
 (** Consonant category *)
 type category =
@@ -13,23 +19,23 @@ type category =
 
 type voyel =
   { opened : bool
-  ; position : [`Above | `Below ]
+  ; position : position_type
   ; app : (position -> string) }
 
 type consonant =
-  { position : position
+  { position : position * position
   ; muted: string option
   ; repr : string
   ; primary : bool
   ; category : category }
 
-
-type nasal = (t -> string)
+type application = (t -> t * t option)
 
 and t =
   | Consonant of consonant
   | Voyel of voyel
-  | Nasal of nasal
+  | Nasal of application
+  | App of application
   | Repr of string
   | Nothing
 
@@ -37,29 +43,40 @@ let none = Nothing
 
 let space s = Repr s
 
-let a = Voyel
-    { opened = true
-    ; position = `Above
-    ; app = function
-        | Pos1 -> "#"
-        | Pos2 -> "E"
-        | Pos3 -> "D"
-        | Pos4 -> "C" }
+let a' =
+  { opened = true
+  ; position = `Above
+  ; app = function
+      | Pos1 -> "#"
+      | Pos2 -> "E"
+      | Pos3 -> "D"
+      | Pos4 -> "C"
+      | Lower1 -> ""
+      | Lower2 -> ""
+  }
+let a = Voyel a'
 
 let app_e = function
   | Pos1 -> "$"
   | Pos2 -> "R"
   | Pos3 -> "F"
   | Pos4 -> "V"
+  | Lower1 -> ""
+  | Lower2 -> ""
 
 and app_eu = function
   | Pos1 -> "Ü"
   | Pos2 -> "Ý"
   | Pos3 -> "Þ"
   | Pos4 -> "ß"
+  | Lower1 -> ""
+  | Lower2 -> ""
+
+let e_opened =
+  Voyel { opened = true ; position = `Above ; app = app_e }
+and e_closed =
+  Voyel { opened = false; position = `Above ; app = app_e }
 
-let e_opened = Voyel { opened = true ; position = `Above ; app = app_e }
-and e_closed = Voyel { opened = false; position = `Above ; app = app_e }
 and schwa = Voyel
     { opened = true
     ; position = `Below
@@ -67,37 +84,55 @@ and schwa = Voyel
         | Pos1 -> "È"
         | Pos2 -> "É"
         | Pos3 -> "Ê"
-        | Pos4 -> "Ë" }
+        | Pos4 -> "Ë"
+        | Lower1 -> "Ë"
+        | Lower2 -> "L"
+    }
 
 and eu_opened = Voyel { opened = true  ; position = `Above ; app = app_eu }
 and eu_closed = Voyel { opened = false ; position = `Above ; app = app_eu }
 
-and o = Voyel
-    { opened = true
-    ; position = `Above
-    ; app = function
-        | Pos1 -> "^"
-        | Pos2 -> "Y"
-        | Pos3 -> "H"
-        | Pos4 -> "N" }
-
-and i = Voyel
-    { opened = true
-    ; position = `Above
-    ; app = function
-        | Pos1 -> "%"
-        | Pos2 -> "T"
-        | Pos3 -> "G"
-        | Pos4 -> "B" }
-
-and y = Voyel
-    { opened = true
-    ; position = `Above
-    ; app = function
-        | Pos1 -> "Ø"
-        | Pos2 -> "Ù"
-        | Pos3 -> "Ú"
-        | Pos4 -> "Û" }
+and o' =
+  { opened = true
+  ; position = `Above
+  ; app = function
+      | Pos1 -> "^"
+      | Pos2 -> "Y"
+      | Pos3 -> "H"
+      | Pos4 -> "N"
+      | Lower1 -> ""
+      | Lower2 -> ""
+  }
+
+let o = Voyel o'
+
+and i' =
+  { opened = true
+  ; position = `Above
+  ; app = function
+      | Pos1 -> "%"
+      | Pos2 -> "T"
+      | Pos3 -> "G"
+      | Pos4 -> "B"
+      | Lower1 -> ""
+      | Lower2 -> ""
+  }
+
+let i = Voyel i'
+
+and y' =
+  { opened = true
+  ; position = `Above
+  ; app = function
+      | Pos1 -> "Ø"
+      | Pos2 -> "Ù"
+      | Pos3 -> "Ú"
+      | Pos4 -> "Û"
+      | Lower1 -> ""
+      | Lower2 -> ""
+  }
+
+let y = Voyel y'
 
 and u = Voyel
     { opened = true
@@ -106,193 +141,191 @@ and u = Voyel
         | Pos1 -> "&"
         | Pos2 -> "U"
         | Pos3 -> "J"
-        | Pos4 -> "M" }
+        | Pos4 -> "M"
+        | Lower1 -> ""
+        | Lower2 -> ""
+    }
 
 and p = Consonant
-    { position = Pos2
+    { position = Pos2, Lower1
     ; muted = Some "y"
     ; category = II
     ; primary = true
     ; repr = "q" }
 
 and b = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = Some "y"
     ; category = II
     ; primary = true
     ; repr = "w" }
 
 and t = Consonant
-    { position = Pos2
+    { position = Pos2, Lower1
     ; muted = Some "6"
     ; category = I
     ; primary = true
     ; repr = "1" }
 
 and d = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = Some "6"
     ; category = I
     ; primary = true
     ; repr = "2" }
 
 and k = Consonant
-    { position = Pos3
+    { position = Pos3, Lower1
     ; muted = Some "h"
     ; category = III
     ; primary = true
     ; repr = "a" }
 
 and g = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = Some "h"
     ; category = III
     ; primary = true
     ; repr = "s" }
 
 and f = Consonant
-    { position = Pos3
+    { position = Pos3, Lower1
     ; muted = None
     ; category = II
     ; primary = true
     ; repr = "e" }
 
 and v = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = II
     ; primary = true
     ; repr = "r" }
 
 and ch = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = III
     ; primary = true
     ; repr = "d" }
 
 and j = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = III
     ; primary = true
     ; repr = "f" }
 
 and s = Consonant
-    { position = Pos4
+    { position = Pos4, Lower1
     ; muted = Some "i"
     ; category = I
     ; primary = true
     ; repr = "3" }
 
 and z = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = I
     ; primary = true
     ; repr = "4" }
 
 and m = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = II
     ; primary = true
     ; repr = "t" }
 
 and n = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = I
     ; primary = true
     ; repr = "5" }
 
 and gn = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = III
     ; primary = false
     ; repr = "b" }
 
-and l = Consonant
-    { position = Pos1
-    ; muted = None
-    ; category = II
-    ; primary = false
-    ; repr = "j" }
-
 and r = Consonant
-    { position = Pos2
-    ; muted = None
+    { position = Pos2, Lower1
+    ; muted = Some "u"
     ; category = I
     ; primary = false
     ; repr = "7" }
 
 and semi_voyel_w = Consonant
-    { position = Pos3
+    { position = Pos3, Lower1
     ; muted = None
     ; category = II
     ; primary = false
     ; repr = "." }
 
 and semi_voyel_y = Consonant
-    { position = Pos1
+    { position = Pos1, Lower1
     ; muted = None
     ; category = II
     ; primary = false
     ; repr = "l" }
 
 and semi_voyel_u = Consonant
-    { position = Pos2
+    { position = Pos2, Lower1
     ; muted = None
     ; category = II
     ; primary = false
     ; repr = "]" }
 
-let nasal v =
-  let Voyel letter = v [@@warning "-8"]in
+let pair
+  : voyel -> consonant -> string
+  = fun voyel consonant ->
+    match voyel.position with
+    | `Above -> voyel.app (fst consonant.position)
+    | `Below -> voyel.app (snd consonant.position)
+
+let l =
+  let default =
+    { position = Pos1, Lower1
+    ; muted = None
+    ; category = II
+    ; primary = false
+    ; repr = "j" } in
+  Consonant default
+
+let nasal letter =
   Nasal
-    ( fun f ->
+    ( function
+      | Consonant { category = II; _} as f ->
+        let Consonant c = m [@@warning "-8"] in
+        let v = pair letter c in
+        let repr = c.repr ^ v in
+        Consonant {c with repr}, Some f
+      | Consonant { category = III; _} as f ->
+        let Consonant c = gn [@@warning "-8"] in
+        let v = pair letter c in
+        let repr = c.repr ^ v in
+        Consonant {c with repr}, Some f
+      | f ->
         let Consonant c = n [@@warning "-8"] in
-        let default = c.repr ^ letter.app c.position in
-
-        match f with
-        | Consonant c -> begin match c.category with
-            | I -> default
-            | II ->
-              let Consonant c = m [@@warning "-8"] in
-              c.repr ^ letter.app c.position
-            | III ->
-              let Consonant c = gn [@@warning "-8"] in
-              c.repr ^ letter.app c.position
-          end
-        | _ -> default
+        let v = pair letter c in
+        let repr = c.repr ^ v in
+        let default = Consonant { c with repr } in
+        default, Some f
     )
+let a_nasal = nasal a'
+and o_nasal = nasal o'
+and i_nasal = nasal i'
+and y_nasal = nasal y'
 
-let a_nasal = nasal a
-and o_nasal = nasal o
-and i_nasal = nasal i
-and y_nasal = nasal y
-
-
-let diphtongue
-  : t -> t -> t
-  = fun t1 t2 -> match t1, t2 with
-    (*
-    | Consonant _, Voyel _ when t1 = semi_voyel_y && t2 = schwa ->
-      Consonant
-        { position = Pos1
-        ; muted = None
-        ; category = II
-        ; primary = false
-        ; repr = "m"}
-        *)
-    | Consonant c, Voyel v ->
-      Repr(c.repr ^ (v.app c.position))
-    | Consonant c, Nasal n ->
-      Repr(c.repr ^ (n none))
-    | _ ->
-      print_endline "Ignoring diphtongue";
-      none
+and portant =
+  { position = Pos4, Lower1
+  ; muted = None
+  ; category = I
+  ; primary = false
+  ; repr = "`" }
 
 let muted
   : t -> t
@@ -306,12 +339,59 @@ let muted
     | _ -> t
 
 
-and portant =
-  { position = Pos4
-  ; muted = None
-  ; category = I
-  ; primary = false
-  ; repr = "`" }
+let diphtongue
+  : t -> t -> t
+  = fun t1 t2 -> match t1, t2 with
+    | Consonant c, Voyel v ->
+
+      Nasal (fun t ->
+          match t with
+          | Nothing ->
+            let repr = c.repr in
+            Repr repr, (Some t2)
+          | Consonant c2 ->
+            let b = Buffer.create 4 in
+            Buffer.add_string b c.repr;
+            Buffer.add_string b c2.repr;
+            let v2 = pair v c2 in
+            Buffer.add_string b v2;
+            let repr = Buffer.contents b in
+            Repr repr, None
+          | Repr r ->
+            let v_repr = pair v portant in
+            Repr(c.repr ^ portant.repr ^ v_repr ^ r), None
+          | Voyel _
+          | Nasal _
+          | App _ ->
+            let b = Buffer.create 4 in
+            let v = pair v portant in
+            Buffer.add_string b c.repr;
+            Buffer.add_string b portant.repr;
+            Buffer.add_string b v;
+            let repr = Buffer.contents b in
+            ( Repr repr
+            , Some t)
+        )
+
+    | Consonant c, Nasal n
+    | Consonant c, App n
+      ->
+      begin match n none with
+        | Consonant c2, _ ->
+          Repr(c.repr ^ c2.repr)
+        | Repr r, _ ->
+          Repr(c.repr ^ r)
+        | Voyel v, _ ->
+          let v_repr = pair v c in
+          Repr(c.repr ^ v_repr)
+        | Nothing, _
+        | Nasal _, _
+        | App _, _ ->
+          t1
+      end
+    | _ ->
+      print_endline "Ignoring diphtongue";
+      none
 
 let fold
   : t list -> string
@@ -326,11 +406,16 @@ let fold
             | Some Nothing
               -> ()
             | Some Voyel ( {position = `Above; _ } as v) ->
-              Buffer.add_string buff ("`" ^ (v.app portant.position))
+              Buffer.add_string buff ("`" ^ (pair v portant))
             | Some Voyel ( {position = `Below; _ } as v) ->
               Buffer.add_string buff (v.app Pos1)
-            | Some Nasal n ->
-              Buffer.add_string buff (n (Consonant portant))
+            | Some Nasal n
+            | Some App n ->
+              let result, next = (n Nothing) in
+              begin match next with
+                | None -> _fold (Some result) []
+                | Some v -> _fold (Some result) [v]
+              end
             | Some Repr r ->
               Buffer.add_string buff r
             | Some Consonant c ->
@@ -341,20 +426,37 @@ let fold
           | Some Nothing, _ -> _fold (Some hd) tl
           | _, Nothing      -> _fold init tl
           | Some Voyel ({position = `Above; _} as v), Consonant c ->
-            Buffer.add_string buff (c.repr ^ (v.app c.position));
+            Buffer.add_string buff (c.repr ^ (pair v c));
             _fold None tl
           | Some Voyel ({position = `Below; _} as v), Consonant c ->
-            Buffer.add_string buff ((v.app Pos1)^ c.repr);
-            _fold None tl
-          | Some Nasal n, Consonant c ->
-            Buffer.add_string buff ((n hd) ^ c.repr);
+            Buffer.add_string buff ((pair v c) ^ c.repr);
             _fold None tl
           | Some Voyel v, _ ->
-            Buffer.add_string buff ("`" ^ (v.app portant.position));
-            _fold (Some hd) tl
-          | Some Nasal n, _ ->
-            Buffer.add_string buff (n (Consonant portant));
+            Buffer.add_string buff ("`" ^ (pair v portant));
             _fold (Some hd) tl
+          | Some Nasal n, Consonant _
+          | Some App n, Consonant _
+            ->
+            let result, next = n hd in
+            begin match next with
+              | None -> _fold (Some result) tl
+              | Some hd -> _fold (Some result) (hd::tl)
+            end
+          | Some Nasal n, Voyel v
+          | Some App n, Voyel v
+            ->
+            let result, next = (n hd) in
+            begin match next with
+              | None -> _fold (Some result) (tl)
+              | Some next -> _fold (Some result) (next::tl)
+            end
+          | Some Nasal n, _
+          | Some App n, _ ->
+            let result, next = (n (Consonant portant)) in
+            begin match next with
+              | None -> _fold (Some result) (hd::tl)
+              | Some next -> _fold (Some result) (next::hd::tl)
+            end
           | Some Repr r, _ ->
             Buffer.add_string buff r;
             _fold (Some hd) tl
@@ -369,7 +471,9 @@ let fold
             Buffer.add_string buff r;
             _fold None tl
           | None, Voyel _
-          | None, Nasal _ -> _fold (Some hd) tl
+          | None, Nasal _
+          | None, App _ ->
+            _fold (Some hd) tl
 
     in
     _fold None elems;