From 79a734af0271de730eeca42157ad587caf835582 Mon Sep 17 00:00:00 2001
From: Michael Leuschel <leuschel@cs.uni-duesseldorf.de>
Date: Mon, 4 Dec 2017 17:12:52 +0100
Subject: [PATCH] fix parsing of empty pairs list

---
 src/json.pl | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/json.pl b/src/json.pl
index ee6ee87..e2cf27f 100644
--- a/src/json.pl
+++ b/src/json.pl
@@ -181,28 +181,29 @@
     array1(T).
 array1([]) --> [], {print_info(empty_array)}.
 
-pair(pair(Name, Value)) -->
+pair(pair(Name, Value),Optional) -->
     spaces,
-    pair_name(Codes),
+    ({Optional=optional} -> opt_pair_name(Codes) ; pair_name(Codes)),
     check_string(":"),
     { atom_codes(Name, Codes) },
     {print_info(pair_value_for(Name))},
     json(Value),
     {print_info(found_value_vor(Name,Value))}.
 
+opt_pair_name(Name) --> """", string(Name), spaces.
 pair_name(Name) --> check_string(""""), string(Name), spaces.
 
 
 pairs(List) --> ws,!,pairs(List).
 pairs([H|T]) -->
-    pair(H), !,
+    pair(H,optional), !,
     pairs1(T).
 pairs([]) --> [], {print_info(empty_pairs)}.
 
 pairs1(List) --> ws,!,pairs1(List).
 pairs1([H|T]) -->
     ",", !,
-    pair(H),!,
+    pair(H,required),!,
     pairs1(T).
 pairs1([]) --> [], {print_info(end_pairs)}.