DrScheme Release Notes
----------------------

Current Release: 0.40.
Release Date: March 22, 1996.

The following is a list of differences between this release and the
previous one.

Editor
------

The long-known instability in the Windows 95/NT version has finally been
corrected. Also, a major instability in the 68k Macintosh version has
been fixed. The Win32s version remains unstable.

Type-Analysis
-------------

The number in parentheses indicates the section in the reference manual
that describes the feature.

* Improved, faster type compression.

* Accurate description of numeric values (4.3).

* Constants (number, character or symbol) in the input type language.

* Type assertions, `(: exp type)’, have been added (5.4).

* `define-type’ changed to `define-constructor’ (5.2).

* `st:deftype’ changed to `st:defconstructor’ (6.2).

* Added `define-type’, `st:deftype’ (5.3 and 6.2).

* Changed `(list T)’ to `(listof T)’ (4.2).

* Added list type with the same same semantics as in Scheme (4.2).

* `(+ T1 ... Tn)’ changed to `(union T1 ... Tn)’ (4.1).

Debugger
--------

A completely new debugger has been incorporated.  This debugger has been
measured to be twenty times or more faster than the previous version.
In particular, the debugger does not do worse than double the execution
time.  In return, the debugger currently reports both incorrect-arity
errors and non-procedural application errors as “application errors”.