What is VITSE?

VITSE (Viivi Interactive Tracing Sytem for Evaluation)
is a collection of functions interacting between the user and Viivi IDE.
It enables the user effectively to understand the Scheme evaluation processes,
and to detect and fix problems in the programs.
Currently available functions can be grouped into four categories as follows:

• Trace-Output

  It was called as "Debug Trace Output" in the previous versions.
  In the new version, it was sophisticated for the beginners to understand the evaluation process.
  Every evaluation step shows a trace line connecting its own input and output, except for restarts of continuations.
  Side-effects, such as updates for bindings and data-structures, interactions through the I/O-ports, and procedure calls (including those for closures, syntaxes, and continuations) are shown as well.
  

• Evaluation-Lit

  During evaluations, "orange cursors" light and indicate the evaluation target and the related objects in real time.
  The user can understand what is happening in Viivi kernel just by following the orange cursors with the eyes.

• Selection-Lit

  During a halt, when the user selects a specific object on a window, "violet cursors" light and indicate the selection target and the related objects.
  The user can understand what is happening in Viivi kernel just by following the violet cursors with the eyes.

• Watch

  This is a general extension of the break-points on the source codes available also in other systems.
  The user can watch, not only arbitrary Scheme objects, but also specific procedure calls, bindings, and even an evaluation count by marking.
  When the evaluation reaches a mark (a watch-point), the evaluation process halts.