From: Matthew Flatt <>
Date: Tue, 25 Jul 2000 08:13:35 -0700
Subject: 103/1

For those of you using CVS, the currently exp-tagged version of
MzScheme and MrEd is now 103/1 (i.e., the 1st pre-release step towards
version 103).

To compile, you’ll need to checkout the new directory
plt/src/wxcommon/jpeg. Windows users will also need

MrEd changes:

 * Added support for JPEG file loading (but not saving) using the IJG
   library. The MrEd executable grew by 70k, which seemed like an
   acceptable amount of bloat for the benefit.

 * Windows: editors can paste bitmaps copied to the clipboard from
   other programs.

 * Windows: fixed get-file-list. (PR 1567)

 * Added `get-clipboard-bitmap’ and `set-clipboard-bitmap’ to
   clipboard<%>. Under Windows, these methods move bitmaps to and from
   the system in a platform-specific format.

 * Changed `graphical-read-eval-print-loop’ to take an optional eventspace
   argument, which determines the evaluation eventspace. The argument
   defaults to #f, which creates a new eventspace for evaluation.

 * Removed ’anchored flag for snip% (wasn’t implemented).

MzScheme changes:

 * Changed `define-values’ to require distinct variables for binding.
   Thus, `(define-values (x x) (values 1 2))’ and `(define-struct make
   (make))’ are now ill-formed expressions. (PR 986)

 * Windows: Fixed bug in `close-output-port’ for TCP ports.

 * Closing a TCP output port always sends an EOF to the other end of
   the connection, even if the associated input port remains open.

 * Added an optional limit argument to `make-pipe’, useful for
   chaining together stream-processing threads. By default,
   `make-pipe’ still creates pipes with no limit on the number of
   unread characters that can be written to the pipe.

 * Added a "" library to MzLib, providing `gzip’, etc. Since
   it’s mostly a blind translation of C code to Scheme, the MzLib
   version runs about 100 times as slow as regular gzip.

 * Added `not-break-exn?’. This procedure is useful mainly as a
   predicate in a `with-handlers’ expression. In particular, most
   expressions of the form
     (with-handlers ([(lambda (x) #t) ..]) ...)
   should be
     (with-handlers ([not-break-exn? ..]) ...)
   instead, to propagate breaks exceptions. This is especially true
   for library procedures.

 * Fixed `load/use-compiled’, `require-library’, and many MzLib
   functions to propagate break exceptions correctly. (Guess how.)

 * Added `check-parameter-procedure’ and changed `parameterize’ to use
   it. With this change `parameterize’ reports a useful error message
   when a parameter expression produces a non-procedure or a procedure
   that does not take 0 and 1 arguments. (PR 1486)

 * Fixed read-write invariance of copiled code, and corrected
   performance bugs (worth about 4% on a tight loop). (PR 1157)

As usual, the pre-release MzScheme and MrEd documentation have been
updated to reflect the changes.