| [ < ] | [ > ] | [ << ] | [ Up ] | [ >> ] | [Top] | [Contents] | [Index] | [ ? ] |
If an expression in your program produces a value containing circular list structure, you may get an error when Edebug attempts to print it.
One way to cope with circular structure is to set print-length
or print-level to truncate the printing. Edebug does this for
you; it binds print-length and print-level to 50 if they
were nil. (Actually, the variables edebug-print-length
and edebug-print-level specify the values to use within Edebug.)
See section 19.6 Variables Affecting Output.
nil, Edebug binds print-length to this value while
printing results. The default value is 50.
nil, Edebug binds print-level to this value while
printing results. The default value is 50.
You can also print circular structures and structures that share
elements more informatively by binding print-circle
to a non-nil value.
Here is an example of code that creates a circular structure:
(setq a '(x y)) (setcar a a) |
Custom printing prints this as `Result: #1=(#1# y)'. The `#1=' notation labels the structure that follows it with the label `1', and the `#1#' notation references the previously labeled structure. This notation is used for any shared elements of lists or vectors.
nil, Edebug binds print-circle to this value while
printing results. The default value is nil.
Other programs can also use custom printing; see `cust-print.el' for details.