VITSE

VITSE (Viivi Interactive Tracing System for Evaluation) is the name for a set of functions for the user to visualize and control the internal processing/evaluations of Viivi IDE, interacting with Viivi IDE.

Currently the function of VITSE can be divided into four groups:

• Trace-Output
• Evaluation-Lit
• Selection-Lit
• Watch

Integrating these functions, VITSE provides the user an extremely effective learning/development environment.

• Function in the Evaluation

  During evaluations, the Evaluation-Lit function works.
  The "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.



• Function in Halt

  During a halt, the Selection-Lit function works.
  When the user selects a specific object on a window, the "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.



• Function after Passing the Hot-Point

  In case of a problem (a bug) generated in the user codes, the user have to detect and fix the point of the bug-generating (let's call it as a "hot-point").
  Usually, this labor requires high concentration and sustaining patience.
  When the possible range of the hot-point resides is wide, the user is forced to work in desperation.
  To make the problem more serious, the user is usually tired-up and cannot concentrate on working in such a situation.
  Even if the user traces the code carefully step by step with a debugger of the general style, once the user passed over the hot-point by mistake, that job have to be repeated from the start.
  The debugging is so stressful.
  
  Using VITSE could reduce more or less the debugging effort.
  Run the buggy program on Viivi up to the point where the bug is likely to occur.
  It is no problem to pass the exact hot-point.
  One of the strongest features of VITSE, which is essentially different from other systems, is that all the evaluation processes are recorded as the trace-output.
  Furthermore, not only reading back the trace-output record by eyes, but also the user can use the Selection-Lit function.
  Even after the bug is generated, the user can investigate all the evaluation processes leading up to the problem in detail, with the input S-expressions and its evaluation values, respectively, together with their internal side-effects, such as bindings and data-structure modifications.
  It is possible effectively to find the hot-point as well as its cause.
  VITSE presents a new way of debugging that has never been seen before.
  

VITSE will continue to be improved more powerful and easier to use, as a unique and key feature of Viivi.