From f2082e90b633866ffa7a452021ae7be115422374 Mon Sep 17 00:00:00 2001
From: Robbert Krebbers <mail@robbertkrebbers.nl>
Date: Thu, 11 Feb 2016 21:43:47 +0100
Subject: [PATCH] Make language notations stable under simpl.

Before they were not, for example:

  Check ('10 + '10 )%L.           (* prints ('10 + '10)%L *)
  Eval simpl in ('10 + '10 )%L.   (* prints (Lit 10 + Lit 10)%L *)

The notation added by this comment is ambigious, for example the
notation '10 + '10 is used for both:

  BinOp PlusOp (Lit (LitNat 10)) (Lit (LitNat 10))
  BinOp PlusOp (of_val (LitV (LitNat 10))) (of_val (LitV (LitNat 10)))

But fortunatelly, these terms are convertible.

Note that literals 'x are now parsed as values (as a LitV), but still
pretty printed when they appear as expressions (as a Lit).
---
 heap_lang/notation.v | 1 +
 1 file changed, 1 insertion(+)

diff --git a/heap_lang/notation.v b/heap_lang/notation.v
index f7ff70f72..72aa0f2eb 100644
--- a/heap_lang/notation.v
+++ b/heap_lang/notation.v
@@ -15,6 +15,7 @@ Coercion of_val : val >-> expr.
 (** Syntax inspired by Coq/Ocaml. Constructions with higher precedence come
     first. *)
 (* What about Arguments for hoare triples?. *)
+Notation "' l" := (Lit l) (at level 8, format "' l") : lang_scope.
 Notation "' l" := (LitV l) (at level 8, format "' l") : lang_scope.
 Notation "! e" := (Load e%L) (at level 10, format "! e") : lang_scope.
 Notation "'ref' e" := (Alloc e%L) (at level 30) : lang_scope.
-- 
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