io: get variables out of stream-copy loop

core/io/io-tests.factor

@@ -1,4 +1,5 @@
-USING: accessors io kernel math parser tools.test words ;
+USING: accessors io io.streams.string kernel math parser sbufs
+sequences tools.test words ;
 IN: io.tests
 
 { f } [
@@ -62,3 +63,6 @@ M: dumb-writer stream-write1 vector>> push ; inline
     [ stream-nl ]
     [ vector>> ] tri
 ] unit-test
+
+{ SBUF" asdf" }
+[ "asdf" <string-reader> 4 <sbuf> [ stream-copy ] keep ] unit-test

core/io/io.factor

@@ -149,9 +149,11 @@ PRIVATE>
 : contents* ( -- seq )
     input-stream get stream-contents* ; inline
 
+: stream-copy* ( in out -- )
+    [ stream-write ] curry each-stream-block ; inline
+
 : stream-copy ( in out -- )
-    [ [ [ write ] each-block ] with-output-stream ]
-    curry with-input-stream ;
+    [ [ stream-copy* ] with-disposal ] curry with-disposal ;
 
 ! Default implementations of stream operations in terms of read1/write1