Node:Pretty Printing, Next:Formatted Output, Previous:Value History, Up:Top
(ice-9 pretty-print) provides the procedure
pretty-print, which provides nicely formatted output of Scheme
objects. This is especially useful for deeply nested or complex data
structures, such as lists and vectors.
The module is loaded by simply saying.
(use-modules (ice-9 pretty-print))
This makes the procedure
pretty-print available. As an example
pretty-print will format the output, see the following:
(pretty-print '(define (foo) (lambda (x) (cond ((zero? x) #t) ((negative? x) -x) (else (if (= x 1) 2 (* x x x))))))) -| (define (foo) (lambda (x) (cond ((zero? x) #t) ((negative? x) -x) (else (if (= x 1) 2 (* x x x))))))
|pretty-print obj [port]||Scheme Procedure|
|Print the textual representation of the Scheme object obj to port. port defaults to the current output port, if not given.|
pretty-print uses it's own write procedure, it's
output will not be the same as for example the output of
Consider the following example.
(write (lambda (x) x)) -| #<procedure #f (x)> (pretty-print (lambda (x) x)) -| #[procedure]
The reason is that
pretty-print does not know as much about
Guile's object types as the builtin procedures. This is particularly
important for smobs, for which a write procedure can be defined and be
write, but not by