elisp: Edebug Execution Modes
17.2.3 Edebug Execution Modes
-----------------------------
Edebug supports several execution modes for running the program you are
debugging. We call these alternatives “Edebug execution modes”; do not
confuse them with major or minor modes. The current Edebug execution
mode determines how far Edebug continues execution before
stopping—whether it stops at each stop point, or continues to the next
breakpoint, for example—and how much Edebug displays the progress of the
evaluation before it stops.
Normally, you specify the Edebug execution mode by typing a command
to continue the program in a certain mode. Here is a table of these
commands; all except for ‘S’ resume execution of the program, at least
for a certain distance.
‘S’
Stop: don’t execute any more of the program, but wait for more
Edebug commands (‘edebug-stop’).
‘<SPC>’
Step: stop at the next stop point encountered (‘edebug-step-mode’).
‘n’
Next: stop at the next stop point encountered after an expression
(‘edebug-next-mode’). Also see ‘edebug-forward-sexp’ in 
Jumping.
‘t’
Trace: pause (normally one second) at each Edebug stop point
(‘edebug-trace-mode’).
‘T’
Rapid trace: update the display at each stop point, but don’t
actually pause (‘edebug-Trace-fast-mode’).
‘g’
Go: run until the next breakpoint (‘edebug-go-mode’).
Breakpoints.
‘c’
Continue: pause one second at each breakpoint, and then continue
(‘edebug-continue-mode’).
‘C’
Rapid continue: move point to each breakpoint, but don’t pause
(‘edebug-Continue-fast-mode’).
‘G’
Go non-stop: ignore breakpoints (‘edebug-Go-nonstop-mode’). You
can still stop the program by typing ‘S’, or any editing command.
In general, the execution modes earlier in the above list run the
program more slowly or stop sooner than the modes later in the list.
When you enter a new Edebug level, Edebug will normally stop at the
first instrumented function it encounters. If you prefer to stop only
at a break point, or not at all (for example, when gathering coverage
data), change the value of ‘edebug-initial-mode’ from its default ‘step’
to ‘go’, or ‘Go-nonstop’, or one of its other values (Edebug
Options). You can do this readily with ‘C-x C-a C-m’
(‘edebug-set-initial-mode’):
-- Command: edebug-set-initial-mode
This command, bound to ‘C-x C-a C-m’, sets ‘edebug-initial-mode’.
It prompts you for a key to indicate the mode. You should enter
one of the eight keys listed above, which sets the corresponding
mode.
Note that you may reenter the same Edebug level several times if, for
example, an instrumented function is called several times from one
command.
While executing or tracing, you can interrupt the execution by typing
any Edebug command. Edebug stops the program at the next stop point and
then executes the command you typed. For example, typing ‘t’ during
execution switches to trace mode at the next stop point. You can use
‘S’ to stop execution without doing anything else.
If your function happens to read input, a character you type
intending to interrupt execution may be read by the function instead.
You can avoid such unintended results by paying attention to when your
program wants input.
Keyboard macros containing the commands in this section do not
completely work: exiting from Edebug, to resume the program, loses track
of the keyboard macro. This is not easy to fix. Also, defining or
executing a keyboard macro outside of Edebug does not affect commands
inside Edebug. This is usually an advantage. See also the
‘edebug-continue-kbd-macro’ option in Edebug Options.
-- User Option: edebug-sit-for-seconds
This option specifies how many seconds to wait between execution
steps in trace mode or continue mode. The default is 1 second.
Info Catalog
elisp: Instrumenting
elisp: Edebug
elisp: Jumping