OCaml 4.12.0, with support for multicore domains
Module type
Class type
Library stdlib
Module Stdlib . Format


For a gentle introduction to the basics of pretty-printing using Format, read http://caml.inria.fr/resources/doc/guides/format.en.html.

You may consider this module as providing an extension to the printf facility to provide automatic line splitting. The addition of pretty-printing annotations to your regular printf format strings gives you fancy indentation and line breaks. Pretty-printing annotations are described below in the documentation of the function Format.fprintf.

You may also use the explicit pretty-printing box management and printing functions provided by this module. This style is more basic but more verbose than the concise fprintf format strings.

For instance, the sequence open_box 0; print_string "x ="; print_space (); print_int 1; close_box (); print_newline () that prints x = 1 within a pretty-printing box, can be abbreviated as printf "@[%s@ %i@]@." "x =" 1, or even shorter printf "@[x =@ %i@]@." 1.

Rule of thumb for casual users of this library:

  • use simple pretty-printing boxes (as obtained by open_box 0);
  • use simple break hints