From f5627254f7d786ebc47c7ed9220ee69e1b7f2dc4 Mon Sep 17 00:00:00 2001
From: Felix Krause <flyx@flyx.org>
Date: Thu, 7 Jan 2016 11:58:33 +0100
Subject: [PATCH] Fixed bug in presenter

---
 private/presenter.nim | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/private/presenter.nim b/private/presenter.nim
index 1a709df..1a3c06a 100644
--- a/private/presenter.nim
+++ b/private/presenter.nim
@@ -253,7 +253,7 @@ proc present*(s: YamlStream, target: Stream, tagLib: YamlTagLibrary,
                 nextState = if length <= 60: dFlowSequenceStart else:
                             dBlockSequenceItem
             of ypsJson:
-                if levels[levels.high] in
+                if levels.len > 0 and levels[levels.high] in
                         [dFlowImplicitMapStart, dFlowImplicitMapValue]:
                     raise newException(YamlPresenterJsonError,
                             "Cannot have sequence as map key in JSON output!")
@@ -457,4 +457,4 @@ proc transform*(input: Stream, output: Stream, style: YamlPresentationStyle,
         tagLib = extendedTagLibrary()
         parser = newParser(tagLib)
     present(parser.parse(input), output, tagLib, style,
-            indentationStep)
\ No newline at end of file
+            indentationStep)