From f530f6c9ed75d77837d2b7b3db05a2ee8b8e5d7e Mon Sep 17 00:00:00 2001 From: Matthew Flatt Date: Mon, 25 Aug 2008 12:34:25 +0000 Subject: [PATCH] note custom-port problems in R6RS conformance description svn: r11411 --- collects/r6rs/scribblings/r6rs.scrbl | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/collects/r6rs/scribblings/r6rs.scrbl b/collects/r6rs/scribblings/r6rs.scrbl index 0ee8b4e2af..0417d768e4 100644 --- a/collects/r6rs/scribblings/r6rs.scrbl +++ b/collects/r6rs/scribblings/r6rs.scrbl @@ -303,6 +303,18 @@ several known ways: is referenced before it is bound, an exception is not raised; instead, the reference produces @|undefined-const|.} + @item{A custom textual port must represent positions using integers, + and the positions must correspond to bytes in a UTF-8 encoding + of the port's data. For custom ports (byte or character) that + support both input and output, beware that buffered input can + create a mismatch between the position implemented by the + custom procedures and the port's current position; the result + from a custom position procedure is automatically adjusted to + account for buffering, and setting the port's position flushes + all buffered bytes, but writing after a read does @emph{not} + automatically reset the port's position to counteract the + effects of buffering.} + @item{The bindings in a namespace produced by @scheme[null-environment] or @scheme[scheme-report-environment] correspond to @|r5rs| bindings instead of @|r6rs| bindings. In particular, @scheme[=>], @scheme[else],