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''.