From 48dfa97f97c6936d14f0dca5a1be1cd2428eee0d Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@factorcode.org>
Date: Sat, 27 Aug 2011 16:44:59 -0700
Subject: [PATCH] nibble-arrays: -1 <nibble-array> should throw an error

---
 basis/nibble-arrays/nibble-arrays-tests.factor | 2 ++
 basis/nibble-arrays/nibble-arrays.factor       | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/basis/nibble-arrays/nibble-arrays-tests.factor b/basis/nibble-arrays/nibble-arrays-tests.factor
index 363f30678d..92a38e509b 100644
--- a/basis/nibble-arrays/nibble-arrays-tests.factor
+++ b/basis/nibble-arrays/nibble-arrays-tests.factor
@@ -1,6 +1,8 @@
 USING: nibble-arrays tools.test sequences kernel math ;
 IN: nibble-arrays.tests
 
+[ -1 <nibble-array> ] [ T{ bad-array-length f -1 } = ] must-fail-with
+
 [ t ] [ 16 iota dup >nibble-array sequence= ] unit-test
 [ N{ 4 2 1 3 } ] [ N{ 3 1 2 4 } reverse ] unit-test
 [ N{ 1 4 9 0 9 4 } ] [ N{ 1 2 3 4 5 6 } [ sq ] map ] unit-test
diff --git a/basis/nibble-arrays/nibble-arrays.factor b/basis/nibble-arrays/nibble-arrays.factor
index 712b62f20b..0e7298165c 100644
--- a/basis/nibble-arrays/nibble-arrays.factor
+++ b/basis/nibble-arrays/nibble-arrays.factor
@@ -30,7 +30,10 @@ CONSTANT: nibble BIN: 1111
 
 PRIVATE>
 
+ERROR: bad-array-length n ;
+
 : <nibble-array> ( n -- nibble-array )
+    dup 0 < [ bad-array-length ] when
     dup nibbles>bytes <byte-array> nibble-array boa ; inline
 
 M: nibble-array length length>> ;
-- 
2.34.1