Unbreak singleton list-like notation (-compat 8.4)

With this commit, it is possible to write notations so that singleton
lists are usable in both 8.4 and 8.5pl1 -compat.  Longer lists await the
ability to remove notations from the parser.

4 files changed, 142 insertions, 0 deletions

diff --git a/test-suite/bugs/closed/4684.v b/test-suite/bugs/closed/4684.v
new file mode 100644
index 000000000..9c0bed42c
--- /dev/null
+++ b/test-suite/bugs/closed/4684.v
@@ -0,0 +1,32 @@
+(*Suppose a user wants to declare a new list-like notation with support for singletons in both 8.4 and 8.5.  If they use*)
+Require Import Coq.Lists.List.
+Require Import Coq.Vectors.Vector.
+Import ListNotations.
+Import VectorNotations.
+Set Implicit Arguments.
+Inductive mylist T := mynil | mycons (_ : T) (_ : mylist T).
+Arguments mynil {_}, _.
+
+Delimit Scope mylist_scope with mylist.
+Bind Scope mylist_scope with mylist.
+Delimit Scope vector_scope with vector.
+
+Notation " [ ] " := mynil (format "[ ]") : mylist_scope.
+Notation " [ x ] " := (mycons x mynil) : mylist_scope.
+Notation " [ x ; y ; .. ; z ] " := (mycons x (mycons y .. (mycons z mynil) ..)) : mylist_scope.
+
+Check [ ]%mylist : mylist _.
+Check [ ]%list : list _.
+Check []%vector : Vector.t _ _.
+Check [ _ ]%mylist : mylist _.
+Check [ _ ]%list : list _.
+Check [ _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ]%list : list _.
+Check [ _ ; _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ]%mylist : mylist _.
+Check [ _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ; _ ]%mylist : mylist _.
+Check [ _ ; _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ; _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ; _ ; _ ]%mylist : mylist _.
diff --git a/test-suite/bugs/closed/4733.v b/test-suite/bugs/closed/4733.v
new file mode 100644
index 000000000..ac0653492
--- /dev/null
+++ b/test-suite/bugs/closed/4733.v
@@ -0,0 +1,52 @@
+(* -*- coq-prog-args: ("-emacs" "-compat" "8.4") -*- *)
+(*Suppose a user wants to declare a new list-like notation with support for singletons in both 8.4 and 8.5.  If they use*)
+Require Import Coq.Lists.List.
+Require Import Coq.Vectors.Vector.
+Import ListNotations.
+Import VectorNotations.
+Set Implicit Arguments.
+Inductive mylist T := mynil | mycons (_ : T) (_ : mylist T).
+Arguments mynil {_}, _.
+
+Delimit Scope mylist_scope with mylist.
+Bind Scope mylist_scope with mylist.
+Delimit Scope vector_scope with vector.
+
+Notation " [ ] " := mynil (format "[ ]") : mylist_scope.
+Notation " [ x ] " := (mycons x mynil) : mylist_scope.
+Notation " [ x ; .. ; y ] " := (mycons x .. (mycons y mynil) ..) : mylist_scope.
+
+(** All of these should work fine in -compat 8.4 mode, just as they do in Coq 8.4.  There needs to be a way to specify notations above so that all of these [Check]s go through in both 8.4 and 8.5 *)
+Check [ ]%mylist : mylist _.
+Check [ ]%list : list _.
+Check []%vector : Vector.t _ _.
+Check [ _ ]%mylist : mylist _.
+Check [ _ ]%list : list _.
+Check [ _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ]%list : list _.
+Check [ _ ; _ ]%vector : Vector.t _ _.
+Fail Check [ _ ; _ ]%mylist : mylist _. (* ideally, this should work, but that requires removing notations from the parser *)
+Check [ _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ]%vector : Vector.t _ _.
+Fail Check [ _ ; _ ; _ ]%mylist : mylist _. (* ideally, this should work, but that requires removing notations from the parser *)
+Check [ _ ; _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ; _ ]%vector : Vector.t _ _.
+Fail Check [ _ ; _ ; _ ; _ ]%mylist : mylist _. (* ideally, this should work, but that requires removing notations from the parser *)
+
+Notation " [ x ; y ; .. ; z ] " := (mycons x (mycons y .. (mycons z mynil) ..)) : mylist_scope.
+(* Now these all work, but not so in 8.4.  If we get the ability to remove notations, and the above fails can be removed, this section can also just be removed. *)
+Check [ ]%mylist : mylist _.
+Check [ ]%list : list _.
+Check []%vector : Vector.t _ _.
+Check [ _ ]%mylist : mylist _.
+Check [ _ ]%list : list _.
+Check [ _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ]%list : list _.
+Check [ _ ; _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ]%mylist : mylist _.
+Check [ _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ; _ ]%mylist : mylist _.
+Check [ _ ; _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ; _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ; _ ; _ ]%mylist : mylist _.
diff --git a/test-suite/bugs/opened/4803.v b/test-suite/bugs/opened/4803.v
new file mode 100644
index 000000000..3ca5c095f
--- /dev/null
+++ b/test-suite/bugs/opened/4803.v
@@ -0,0 +1,34 @@
+(* -*- coq-prog-args: ("-emacs" "-compat" "8.4") -*- *)
+(*Suppose a user wants to declare a new list-like notation with support for singletons in both 8.4 and 8.5.  If they use*)
+Require Import Coq.Lists.List.
+Require Import Coq.Vectors.Vector.
+Import ListNotations.
+Import VectorNotations.
+Set Implicit Arguments.
+Inductive mylist T := mynil | mycons (_ : T) (_ : mylist T).
+Arguments mynil {_}, _.
+
+Delimit Scope mylist_scope with mylist.
+Bind Scope mylist_scope with mylist.
+Delimit Scope vector_scope with vector.
+
+Notation " [ ] " := mynil (format "[ ]") : mylist_scope.
+Notation " [ x ] " := (mycons x mynil) : mylist_scope.
+Notation " [ x ; .. ; y ] " := (mycons x .. (mycons y mynil) ..) : mylist_scope.
+
+(** All of these should work fine in -compat 8.4 mode, just as they do in Coq 8.4.  There needs to be a way to specify notations above so that all of these [Check]s go through in both 8.4 and 8.5 *)
+Check [ ]%mylist : mylist _.
+Check [ ]%list : list _.
+Check []%vector : Vector.t _ _.
+Check [ _ ]%mylist : mylist _.
+Check [ _ ]%list : list _.
+Check [ _ ]%vector : Vector.t _ _.
+Check [ _ ; _ ]%list : list _.
+Check [ _ ; _ ]%vector : Vector.t _ _.
+Fail Check [ _ ; _ ]%mylist : mylist _. (* ideally, this should work, but that requires removing notations from the parser; it should be added to Compat/Coq84.v *)
+Check [ _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ]%vector : Vector.t _ _.
+Fail Check [ _ ; _ ; _ ]%mylist : mylist _. (* ideally, this should work, but that requires removing notations from the parser *)
+Check [ _ ; _ ; _ ; _ ]%list : list _.
+Check [ _ ; _ ; _ ; _ ]%vector : Vector.t _ _.
+Fail Check [ _ ; _ ; _ ; _ ]%mylist : mylist _. (* ideally, this should work, but that requires removing notations from the parser *)
diff --git a/theories/Compat/Coq84.v b/theories/Compat/Coq84.v
index aa4411704..574f283f1 100644
--- a/theories/Compat/Coq84.v
+++ b/theories/Compat/Coq84.v
@@ -66,3 +66,27 @@ Coercion sigT_of_sig : sig >-> sigT.
 Coercion sig_of_sigT : sigT >-> sig.
 Coercion sigT2_of_sig2 : sig2 >-> sigT2.
 Coercion sig2_of_sigT2 : sigT2 >-> sig2.
+
+(** As per bug #4733 (https://coq.inria.fr/bugs/show_bug.cgi?id=4733), we want the user to be able to create custom list-like notatoins that work in both 8.4 and 8.5.  This is necessary.  These should become compat 8.4 notations in the relevant files, but these modify the parser (bug #4798), so this cannot happen until that bug is fixed. *)
+Require Coq.Lists.List.
+Require Coq.Vectors.VectorDef.
+Module Export Coq.
+Module Export Lists.
+Module List.
+Module ListNotations.
+Include Coq.Lists.List.ListNotations.
+Notation " [ x ; .. ; y ] " := (cons x .. (cons y nil) ..) : list_scope.
+End ListNotations.
+End List.
+End Lists.
+Module Export Vectors.
+Module VectorDef.
+Module VectorNotations.
+Import Coq.Vectors.VectorDef.VectorNotations.
+Notation " [ x ; .. ; y ] " := (VectorDef.cons _ x _ .. (VectorDef.cons _ y _ (nil _)) ..) : vector_scope.
+End VectorNotations.
+End VectorDef.
+End Vectors.
+End Coq.
+Export Vectors.VectorDef.VectorNotations.
+Export List.ListNotations.