Hi all, The report says whitechar -> newline | return | linefeed | vertab | formfeed | space | tab | uniWhite newline -> a newline (system dependent) return -> a carriage return linefeed -> a line feed so, if your system defines a newline to be a line feed, an implementation is free to choose whether to lex a line feed as a whitechar or a newline, which makes quite a difference when you consider the layout rule! newline can't be arbitrarily determined by the system - certainly "x" or "let" would not be acceptable - and having it system dependent means that Haskell scripts are not portable between different systems. I haven't looked but I would be surprised if current implementations behaved differently on different platforms - I assume they all look for something matching (<CR><LF>?)|<LF> everywhere. I propose replacing the above with the following. It does mean that <CR><LF> creates 2 newlines, but I don't believe this should be a problem. whitechar -> newline | vertab | formfeed | space | tab | uniWhite newline -> return | linefeed return -> a carriage return linefeed -> a line feed Thanks Ian, who really should have noticed this months ago