From 943cecb9ced31363442881fd25d2dc44da0ef7c3 Mon Sep 17 00:00:00 2001
From: Enrico Tassi <enrico.tassi@inria.fr>
Date: Wed, 9 Apr 2008 15:13:59 +0000
Subject: [PATCH] pp with parenthesis only when necessary and with some more
 boxes

---
 helm/software/components/ng_kernel/nCicPp.ml | 52 ++++++++++++--------
 1 file changed, 32 insertions(+), 20 deletions(-)

diff --git a/helm/software/components/ng_kernel/nCicPp.ml b/helm/software/components/ng_kernel/nCicPp.ml
index 82349980f..5a96545fe 100644
--- a/helm/software/components/ng_kernel/nCicPp.ml
+++ b/helm/software/components/ng_kernel/nCicPp.ml
@@ -47,70 +47,82 @@ let trivial_pp_term ~context ~subst ~metasenv ?(inside_fix=false) t =
   let buff = Buffer.create 100 in
   let f = Format.formatter_of_buffer buff in
   let module F = Format in
-  let rec aux ctx = function
+  let rec aux ?(toplevel=false) ctx = function
    | C.Rel m ->
        (try F.fprintf f "%s" (List.nth ctx (m-1))
        with Failure _ -> F.fprintf f " -%d" (m - List.length context))
    | C.Const r -> F.fprintf f "%s" (r2s inside_fix r)
    | C.Prod ("_",s,t) -> 
+       if not toplevel then F.fprintf f "(";
        F.fprintf f "@[<hov 1>";
-       aux ctx s; 
+       aux ~toplevel:true ctx s; 
        F.fprintf f "@;→ ";
-       aux ("_"::ctx) t;
+       aux ~toplevel ("_"::ctx) t;
        F.fprintf f "@]";
+       if not toplevel then F.fprintf f ")";
    | C.Prod (name,s,t) -> 
+       if not toplevel then F.fprintf f "(";
        F.fprintf f "@[<hov 1>";
        F.fprintf f "@[<hov 2>∀%s:@;" name;
-       aux ctx s; 
+       aux ~toplevel:true ctx s; 
        F.fprintf f "@].@;";
-       aux (name::ctx) t;
+       aux ~toplevel (name::ctx) t;
        F.fprintf f "@]";
+       if not toplevel then F.fprintf f ")";
    | C.Lambda (name,s,t) -> 
+       if not toplevel then F.fprintf f "(";
        F.fprintf f "@[<hov 1>";
        F.fprintf f "λ%s:" name;
-       aux ctx s; 
+       aux ~toplevel:true ctx s; 
        F.fprintf f ".@;";
-       aux (name::ctx) t;
+       aux ~toplevel (name::ctx) t;
        F.fprintf f "@]";
+       if not toplevel then F.fprintf f ")";
    | C.LetIn (name,ty,t,b) -> 
-       F.fprintf f "let %s:" name;
-       aux ctx ty;
-       F.fprintf f "≝@;";
-       aux ctx t;
-       F.fprintf f "in@;";
-       (aux (name::ctx) b)
+       if not toplevel then F.fprintf f "(";
+       F.fprintf f "@[<hov 1>";
+       F.fprintf f "let %s:@;" name;
+       aux ~toplevel:true ctx ty;
+       F.fprintf f "@;≝ ";
+       aux ~toplevel:true ctx t;
+       F.fprintf f "@;in@;";
+       (aux ~toplevel (name::ctx) b);
+       F.fprintf f "@]";
+       if not toplevel then F.fprintf f ")";
    | C.Match (r,oty,t,pl) ->
        F.fprintf f "@[<hov>match ";
-       aux ctx t;
+       aux ~toplevel:true ctx t;
        F.fprintf f "@;return ";
-       aux ctx oty;
+       aux ~toplevel:true ctx oty;
        F.fprintf f "@; @[<v>[ ";
        if pl <> [] then
          begin
            F.fprintf f "@[<hov 2>%s ⇒@;" (r2s inside_fix (R.mk_constructor 1 r));
-           aux ctx (List.hd pl);
+           aux ~toplevel:true ctx (List.hd pl);
            F.fprintf f "@]";
            ignore(List.fold_left 
              (fun i t -> 
               F.fprintf f "@;| @[<hov 2>%s ⇒@;" (r2s inside_fix (R.mk_constructor i r));
-              aux ctx t; 
+              aux ~toplevel:true ctx t; 
               F.fprintf f "@]";
               i+1)
              2 (List.tl pl));
          end;
       F.fprintf f "]@] @]";
    | C.Appl l -> 
-       F.fprintf f "@[<hv 2>(";
+       F.fprintf f "@[<hov 2>";
+       if not toplevel then F.fprintf f "(";
        aux ctx (List.hd l);
        List.iter (fun x -> F.fprintf f "@;";aux ctx x) (List.tl l);
-       F.fprintf f ")@]"
+       if not toplevel then F.fprintf f ")";
+       F.fprintf f "@]"
    | C.Implicit _ -> F.fprintf f "?"
    | C.Meta (n,_) -> F.fprintf f "?%d" n
    | C.Sort C.Prop -> F.fprintf f "Prop"
    | C.Sort C.CProp -> F.fprintf f "CProp"
    | C.Sort (C.Type n) -> F.fprintf f "Type%d" n
   in 
-  aux (List.map fst context) t;
+  aux ~toplevel:true (List.map fst context) t;
   F.fprintf f "@?";
   Buffer.contents buff
 ;;
-- 
2.39.2