The Debugger

Select the Popup button in the Chooser to open the debugger window.

The debugger window is divided into the main region with the name of the current procedure (Proc), a listing in which the expression just executed is highlighted, the Result of this execution and the currently available Variables and their values, an entry to Eval expressions in the context of the current procedure and some button controls for the state of the debugger.

A procedure listing displayed in the main region will have a darker background on all lines that have been prepared. You can prepare or restore additional lines by selecting a region (<Button1>, standard selection) and choosing Selection > Prepare Proc or Selection > Restore Proc from the debugger menu (or by pressing ^P or ^R).

When using `Prepare' and `Restore', try to be smart about what you intend to do. If you select just a single word (plus some optional white space) it will be interpreted as the name of a procedure to prepare or restore. Otherwise, if the selection is owned by the listing, the corresponding lines will be used.

Be careful with partial prepare or restore! If you prepare random lines inside a `switch' or `bind' expression, you may get surprising results on execution, because the parser doesn't know about the surrounding expression and can't try to prevent problems.

There are seven possible debugger states, one for each button and an `idle' or `waiting' state when no button is active. The button-activated states are:

Button	Description
Stop	stop after next expression, used to get out of slow/fast/nonstop mode
Next	execute one expression, then revert to idle
Slow	execute until end of procedure, stopping at breakpoints or when the state changes to stop; after each execution, stop for `delay' milliseconds; the delay can be changed with the `+' and `-' buttons
Fast	execute until end of procedure, stopping at breakpoints
Nonstop	execute until end of procedure without stopping at breakpoints or updating the display
Break	terminate execution of current procedure

Closing the debugger doesn't quit it, it only does `wm withdraw'. The debugger window will pop up the next time a prepared procedure is called. Make sure you close the debugger with Debugger > Close.

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