advice.txt

Using PyModel: miscellaneous tips and advice


Workflow

Here is a recommended workflow for building up models.

1. Add just one or two actions at a time. 

2. Using just the actions you have added so far, write down some
sample traces by hand.  In addition to traces that should be allowed,
write some erroneous traces that should be forbidden.

3. In the model program, code just those actions, their enabling
conditions, and any state variables needed to support them.

3. Use pma to generate the FSM, then pmg then dotsvg to generate
graphics, then display the .svg file in a browser.  Follow the action
arrows around the graph to visualize traces.  Generate some traces
with pmt.  If they aren't right, fix the model.

4. Recall the traces you wrote in step 2.  Code them by hand as a test
suite module (each trace becomes one run in the test suite).  Run the
tester, pmt, with both the model program and the test suite as command
arguments (so the model program is composed with each trace).  Each
allowed trace should run to the end (reach an accepting state) and
each orbidden trace should stop before the end (in a non-accepting
state).  If not, fix the model.  You can also run the analyzer, pma.
but it only shows the first trace in a test suite.  It should show all
the steps in an allowed trace and reach the last state (an accepting
state).

Repeat steps 1 - 4 as you add more actions.

There are examples of each step in the samples directories.


Revised January 2010