Version history

April 2005 version

  • Support for animation and interaction added.
  • The Style datatype and associated "styles" mechanism simplified and generalised (including addition of the View style).
  • A (stripped-down) type class mechanism added.
  • Selectable rectangles (SelRect) added to the Pic datatype.
  • The Edit class, and supporting mechanisms added. (The methods of this class allows styles to be inferred automatically and support direct manipulation of ADT values.)
  • Facilities to create and play Midi sequences.
  • Scroll-bars added, and option to suppress display of the Edit panel.
  • New standard stylesheet that includes "semantic" markup comment tags (such as "title", "abstract" and "heading"), allowing automatic indexing and cross-referencing of documents.
  • Operator precedences and associativities are handled correctly.
  • Support for the Array type added.
  • Simplified form of Actions (ie, corresponding to values of type IO ()) added. This allows events (such as file output) to be initiated, sequenced and delayed.

May 2004 version

  • Website redesigned, and Tutorial section added
  • Hyperlink navigation between Haskell documents added
  • A number of loose ends of implementation tidied up
  • Examples on Exact Real Arithmetic added (more are planned)

Sept 2003 version

A complete re-implementation:
  • New scheme for styles introduced
  • Multiple modules supported
  • Compiles to G-machine code, then interpreted
  • Uses Java Web Start mechanism for deployment

Nov 2000 version

The first implementation ('proof of concept'):
  • Document based GUI, with display-driven evaluation
  • Scheme for styles provides a single style per datatype (turned out to be a major limitation)
  • Single module only
  • Uses Java applet mechanism for deployment (highly tempermental!)
  • Interpretative graph reduction (very slow!)

Feedback on any aspect of Vital is welcome. Updated Dec 04
Keith Hanna
Functional Programming group
University of Kent