4.12.3 Pretty-Print

(require 'pretty-print)

Procedure: pretty-print obj

Procedure: pretty-print obj port

pretty-prints obj on port. If port is not specified, current-output-port is used.

Example:

(pretty-print '((1 2 3 4 5) (6 7 8 9 10) (11 12 13 14 15)
                (16 17 18 19 20) (21 22 23 24 25)))
   -| ((1 2 3 4 5)
   -|  (6 7 8 9 10)
   -|  (11 12 13 14 15)
   -|  (16 17 18 19 20)
   -|  (21 22 23 24 25))

Procedure: pretty-print->string obj

Procedure: pretty-print->string obj width

Returns the string of obj pretty-printed in width columns. If width is not specified, (output-port-width) is used.

Example:

(pretty-print->string '((1 2 3 4 5) (6 7 8 9 10) (11 12 13 14 15)
                        (16 17 18 19 20) (21 22 23 24 25)))
⇒
"((1 2 3 4 5)
 (6 7 8 9 10)
 (11 12 13 14 15)
 (16 17 18 19 20)
 (21 22 23 24 25))
"

(pretty-print->string '((1 2 3 4 5) (6 7 8 9 10) (11 12 13 14 15)
                        (16 17 18 19 20) (21 22 23 24 25))
                      16)
⇒
"((1 2 3 4 5)
 (6 7 8 9 10)
 (11
  12
  13
  14
  15)
 (16
  17
  18
  19
  20)
 (21
  22
  23
  24
  25))
"

(require 'pprint-file)

Procedure: pprint-file infile

Procedure: pprint-file infile outfile

Pretty-prints all the code in infile. If outfile is specified, the output goes to outfile, otherwise it goes to (current-output-port).

Function: pprint-filter-file infile proc outfile

Function: pprint-filter-file infile proc

infile is a port or a string naming an existing file. Scheme source code expressions and definitions are read from the port (or file) and proc is applied to them sequentially.

outfile is a port or a string. If no outfile is specified then current-output-port is assumed. These expanded expressions are then pretty-printed to this port.

Whitepsace and comments (introduced by ;) which are not part of scheme expressions are reproduced in the output. This procedure does not affect the values returned by current-input-port, current-error-port, and current-output-port.

pprint-filter-file can be used to pre-compile macro-expansion and thus can reduce loading time. The following will write into exp-code.scm the result of expanding all defmacros in code.scm.

(require 'pprint-file)
(require 'defmacroexpand)
(defmacro:load "my-macros.scm")
(pprint-filter-file "code.scm" defmacro:expand* "exp-code.scm")