From 9e12db445959ce7c791ec7480ea08e9e02f96bba Mon Sep 17 00:00:00 2001
From: ephja <ephja@yandex.com>
Date: Sat, 1 Jul 2017 09:56:20 +0200
Subject: [PATCH] fixes #6030 (#6042)

---
 compiler/typesrenderer.nim | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/compiler/typesrenderer.nim b/compiler/typesrenderer.nim
index e9c27ac9d3..74eb00f4e9 100644
--- a/compiler/typesrenderer.nim
+++ b/compiler/typesrenderer.nim
@@ -52,13 +52,16 @@ proc renderType(n: PNode): string =
     else:
       result = "ptr"
   of nkProcTy:
-    assert len(n) > 1
-    let params = n[0]
-    assert params.kind == nkFormalParams
-    assert len(params) > 0
-    result = "proc("
-    for i in 1 .. <len(params): result.add(renderType(params[i]) & ',')
-    result[<len(result)] = ')'
+    assert len(n) != 1
+    if len(n) > 1:
+      let params = n[0]
+      assert params.kind == nkFormalParams
+      assert len(params) > 0
+      result = "proc("
+      for i in 1 .. <len(params): result.add(renderType(params[i]) & ',')
+      result[<len(result)] = ')'
+    else:
+      result = "proc"
   of nkIdentDefs:
     assert len(n) >= 3
     let typePos = len(n) - 2