From 40fce665b8521a1b0c560d9fb41fde33ae66352d Mon Sep 17 00:00:00 2001
From: Gabriel Gonzalez <Gabriel439@gmail.com>
Date: Sat, 20 Jul 2019 10:42:46 -0700
Subject: [PATCH] Left-factor grammar for domains (#647)

These rules should be equivalent but more amenable to
recursive descent parsers and bulk parsing operators
---
 standard/dhall.abnf | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/standard/dhall.abnf b/standard/dhall.abnf
index 4ad5ea0ee..299adb637 100644
--- a/standard/dhall.abnf
+++ b/standard/dhall.abnf
@@ -578,9 +578,9 @@ dec-octet = "25" %x30-35       ; 250-255
 
 ; Look in RFC3986 3.2.2 for
 ; "A registered name intended for lookup in the DNS"
-domain = *(domainlabel ".") domainlabel [ "." ]
+domain = domainlabel *("." domainlabel) [ "." ]
 
-domainlabel = ALPHANUM *(((ALPHANUM / 1*"-") ALPHANUM) / ALPHANUM)
+domainlabel = 1*ALPHANUM *(1*"-" 1*ALPHANUM)
 
 segment = *pchar