step form[Macro]
- Starts evaluating the it form in the single-step mode. In this mode, before any form is evaluated,
the Stepper will print the form and prompt the user
for a Stepper command. The Stepper binds
the two variables *print-level* and *print-length* both to
2, so that the current form may not occupy too much
space on the screen. A Stepper command will be executed when the user types
the single character for the command followed by the required
arguments, if any, and presses the newline key. If the user presses the
newline key without having typed any character,
then the Stepper will assume that the Stepper command
n was abbreviated.
The Stepper commands are:
- n
- Next. Evaluates the current form in the single-step mode.
- s
- Skip. Evaluates the current form in the ordinary mode. The single-step mode will be resumed at completion
of the evaluation.
- p
- Print. Pretty-prints the current form and then prompts again.
- ffn
- Function. Evaluates the current form in the ordinary mode until the specified
function fn is invoked. If the specified function is not invoked at all, then this command has the same effects as the q command below.
- q
- Quit. Evaluates the current form and any other forms in the ordinary mode.
- eform
- Eval. Evaluates the specified form in the ordinary mode and prints the resulting values. Then prompts again with the same current form.
- ?
- Help. Lists the Stepper commands.