From 3a9cfeb9fb02017bda77c1e9b1f06eb179f116af Mon Sep 17 00:00:00 2001
From: Leonardo de Moura <leonardo@microsoft.com>
Date: Sun, 30 Aug 2020 08:37:51 -0700
Subject: [PATCH] fix: `lookahead.formatter`

---
 src/Lean/PrettyPrinter/Formatter.lean | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Lean/PrettyPrinter/Formatter.lean b/src/Lean/PrettyPrinter/Formatter.lean
index 32c8e38e23..5def533fdb 100644
--- a/src/Lean/PrettyPrinter/Formatter.lean
+++ b/src/Lean/PrettyPrinter/Formatter.lean
@@ -230,7 +230,7 @@ p
 
 @[combinatorFormatter Lean.Parser.lookahead]
 def lookahead.formatter (p : Formatter) : Formatter :=
-p
+pure ()
 
 @[combinatorFormatter Lean.Parser.andthen]
 def andthen.formatter (p1 p2 : Formatter) : Formatter :=