25.9 Configuring the Stepper

To configure the Stepper tool, raise the Preferences dialog, by choosing Tools > Preferences... or clicking . Then select Stepper in the list on the left side of the Preferences dialog.

The Stepper Preferences have three tabs:

• The General tab controls display of the Stepper toolbar, as described in 3.1.8 Toolbar configurations.
• The Operators tab contains options controlling the behavior when the stepper sees functions or macros in the source.
• The Backtrace tab controls the amount of information shown automatically in the Backtrace area.

25.9.1 Operator preferences

When reaching a function call you can use the Step Through Call command to step through the call into its definition. You can configure the Stepper to do this automatically, never do this or ask you which action to take.

Similarly when reaching a macro form you can macroexpand it (or not). You can configure the Stepper to macroexpand automatically, never macroexpand or ask you whether to macroexpand..

For a given symbol naming a function or macro, the action is determined by the preferences in the Operators tab. If the symbol is listed, then the corresponding action is taken. Otherwise, if the symbol's package is listed, then the corresponding action is taken. If neither the symbol nor its package are shown,. then the default action is taken.

For example, the default behavior on reaching your macro forms is to prompt for whether to macroexpand. To configure the Stepper such that macros defined in the CL-USER package are macroexpanded automatically, click the Add... button, enter CL-USER in the Name pane of the dialog, select Always in the Expand macros panel, click OK and click OK to dismiss the Preferences dialog.

To configure the Stepper such that it never steps through my-function, raise the Stepper preferences again, click the Add... button and select the Symbol radio button. Enter cl-user::my-function in the Name pane of the dialog, select Never in the Step through calls panel, click OK and click OK to dismiss the Preferences dialog.

25.9.2 Backtrace preferences

To control the amount of information displayed automatically in the Backtrace area, select the Backtrace tab of the Stepper Preferences:

By default the status item in the Backtrace area automatically expands to show the arguments or return values. To change this behavior, select No against Expand status automatically.

By default the active frame in the Backtrace area automatically expands to show the local variables and arguments. To change this behavior, select No against Expand active frame automatically.

Compatibility Note: in LispWorks 5.0 these Backtrace options have the opposite default values. This is changed in LispWorks 5.1 and later versions.