Tutorial 5 - Configuring the Trace Display

In this exercise we again use the grammar from the "expressions" example to examine the features controlling the display of those records saved during the parsing process. If you haven't already, you should complete tutorial 4 before doing these exercises.

First click Generate then follow the intructions below.

To begin,
1. click Configure
2. check the "Save Parser Trace" box
3. check the TLS box
4. uncheck the alpha and digit boxes
5. save and finish.

The result should be familiar from the previous exercise. Now click "Display Filter" below. This looks very similar to the Configure box for the parser with a few signicant differences.
Line Range Filter: This section works exactly as before, except, of course, the filtering is on the set of saved records.
Final States: This section is new. Now that the parse is complete, we know the final state of each node in advance and we can select only the final states of interest. For, example, uncheck the matched and empty boxes, save and click Display Trace again. Note that only unmatched states appear along with their matching opening records.
Operator Filter - Node Type Operators: Here we also see a difference. All of the operator types that were unchecked the the Parser Configuration are disabled here. Obviously, if those records weren't saved, there is no way to select them for display here. But you can, if you like, unselect TLS and remove those node records from the display.
Operator Filter - Rule Name Operators: Here again, the unchecked rules in Parser Configure are disabled and unavailable for display. But you can show or hide the remaining rule name nodes records.