webbrowser: support open-url on "url-like" strings.

basis/webbrowser/webbrowser.factor

@@ -1,7 +1,8 @@
 ! Copyright (C) 2011 John Benediktsson
 ! See http://factorcode.org/license.txt for BSD license
 
-USING: combinators present system ui.operations urls vocabs ;
+USING: combinators combinators.short-circuit present sequences strings system
+ui.operations urls vocabs ;
 
 IN: webbrowser
 
@@ -17,3 +18,8 @@ HOOK: open-file os ( path -- )
     >url present open-file ;
 
 [ url? ] \ open-url H{ } define-operation
+
+PREDICATE: url-like < string
+    { [ "http://" head? ] [ "https://" head? ] } 1|| ;
+
+[ url-like? ] \ open-url H{ } define-operation