improve library

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@2122 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

library/lineutils.yap

@@ -5,11 +5,13 @@
 	   split/3,
 	   glue/3,
 	   filter/3,
+	   file_filter/3,
+	   process/2,
 	   copy_line/2,
 	   file_filter/3
 	  ]).
 
-:- meta_predicate filter(+,+,:).
+:- meta_predicate filter(+,+,:), file_filter(+,+,:), process(+,:).
 
 :- use_module(library(lists),
 	      [member/2,
@@ -81,6 +83,19 @@ filter(StreamInp, StreamOut, Command) :-
 	).
 
 
+process(StreamInp, Command) :-
+	repeat,
+	read_line_to_codes(StreamInp, Line),
+	(
+	 Line == end_of_file
+	->
+	 true
+	;
+	 call(Command, Line),
+	 fail
+	).
+
+
 file_filter(Inp, Out, Command) :-
 	open(Inp, read, StreamInp),
 	open(Out, write, StreamOut),