io.streams.throwing: implement tell and seek

basis/io/streams/throwing/throwing-tests.factor

@@ -1,7 +1,7 @@
 ! Copyright (C) 2010 Doug Coleman.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: io io.streams.limited io.streams.string
-io.streams.throwing tools.test ;
+io.streams.throwing tools.test kernel ;
 IN: io.streams.throwing.tests
 
 [ "as" ]
@@ -34,3 +34,13 @@ IN: io.streams.throwing.tests
     "asdf" <string-reader> 2 <limited-stream>
     [ contents contents ] throws-on-eof
 ] [ stream-exhausted? ] must-fail-with
+
+[
+    "asdf" <string-reader> 2 <limited-stream>
+    [ 1 seek-absolute seek-input 4 read drop ] throws-on-eof
+] [ stream-exhausted? ] must-fail-with
+
+[ 1 ] [
+    "asdf" <string-reader> 2 <limited-stream>
+    [ 1 seek-absolute seek-input tell-input ] throws-on-eof
+] unit-test

basis/io/streams/throwing/throwing.factor

@@ -28,6 +28,12 @@ M:: throws-on-eof stream-read-partial ( n stream -- seq )
     n stream stream>> stream-read-partial
     [ n stream \ read-partial stream-exhausted ] unless* ;
 
+M: throws-on-eof stream-tell
+    stream>> stream-tell ;
+
+M: throws-on-eof stream-seek
+    stream>> stream-seek ;
+
 PRIVATE>
 
 : throws-on-eof ( stream quot -- )