DrScheme Release Notes

Current Release: 45
Release Date: November 12, 1996.

Send bug reports to: plt-bugs@cs.rice.edu

The following is a summary of the major changes in this release from the
previous one.


* Scheme I/O through `read’, `read-char’, and `read-line’ is now
  supported. All I/O is specially boxed in the interactive console to
  distinguish it from evaluator I/O.

* Two syntactic forms are not yet supported: `do’ without the step form
  and `define-structure’ (use `define-struct’ instead).


* The Analysis tool (MrSpidey) is temporarily unavailable in release 45
  and will reappear in a future release.


* A new construct has been added: eventspaces. An eventspace
  encapsulates an independent event loop. A single running MrEd can
  contain multiple eventspaces, each owning a collection of top-level
  windows that are connected through the event loop, but indepedent of
  event-handling for other eventspaces. This supports a better
  integration of asynchonous threads and synchnous eventspaces.

* A prototype Web browser is available through the standard "Open
  URL..."  menu item in the "File" menu.

* See plt/mred/HISTORY and plt/mred/system/history in the distribution
  for more information and other changes.


* Multiple return values are now agressively supported, and new forms
  `define-values’, `letrec-values’, `set!-values’, etc. have been added.

  IMPORTANT: The `let-values’ of previous versions is now
  `let*-values’. The new `let-values’ binds a sequence of identifier
  sets all with the same enviornment.

* See `plt/mzscheme/HISTORY’ in the distribution for more information
  and other changes.

Known Problems

* DrScheme internally normalizes pathnames, resolving all links to
  absolute paths. This causes problems with systems that use

* Even in the R4RS language level, DrScheme does not support
  case-insensitive identifiers.

* The `eval’ procedure is not supported.

* See also `plt/openbugs’ in the distribution.