From 08a80e5ba22ac457da60c526c1c06f73a83b123d Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@slava-pestovs-macbook-pro.local>
Date: Sat, 20 Feb 2010 12:05:12 +1300
Subject: [PATCH] specialized-arrays: generate slightly more efficient
 byte-array>T-array words

---
 .../specialized-arrays/specialized-arrays.factor  | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/basis/specialized-arrays/specialized-arrays.factor b/basis/specialized-arrays/specialized-arrays.factor
index d3db93e788..e2840b89dd 100644
--- a/basis/specialized-arrays/specialized-arrays.factor
+++ b/basis/specialized-arrays/specialized-arrays.factor
@@ -1,4 +1,4 @@
-! Copyright (C) 2008, 2009 Slava Pestov.
+! Copyright (C) 2008, 2010 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors alien alien.c-types alien.data alien.parser
 assocs byte-arrays classes compiler.units functors kernel lexer
@@ -19,6 +19,11 @@ ERROR: bad-byte-array-length byte-array type ;
 M: bad-byte-array-length summary
     drop "Byte array length doesn't divide type width" ;
 
+ERROR: not-a-byte-array alien ;
+
+M: not-a-byte-array summary
+    drop "Not a byte array" ;
+
 : (underlying) ( n c-type -- array )
     heap-size * (byte-array) ; inline
 
@@ -61,9 +66,11 @@ TUPLE: A
     [ \ T heap-size calloc ] keep <direct-A> ; inline
 
 : byte-array>A ( byte-array -- specialized-array )
-    >c-ptr dup length \ T heap-size /mod 0 =
-    [ drop \ T bad-byte-array-length ] unless
-    <direct-A> ; inline
+    >c-ptr dup byte-array? [
+        dup length \ T heap-size /mod 0 =
+        [ <direct-A> ]
+        [ drop \ T bad-byte-array-length ] if
+    ] [ not-a-byte-array ] if ; inline
 
 M: A clone [ underlying>> clone ] [ length>> ] bi <direct-A> ; inline