format

Many Scheme implementations have more-or-less a subset of CommonLisp's format function, but there're wide variations in detail.

[procedure] format output format-spec obj ...

ChezScheme: supports all of the Common Lisp format directives except for those specific to the Common Lisp pretty printer.

Chicken: implements almost complete spec of CommonLisp's format function in the module format.

There is a format in extras, with only a few formatting directives. See also fprintf, printf, sprintf.

Example:

(use extras) 
(format #t "Example output ~a: ~a~%" 1 20)

=> Example output 1: 20

SLIB: implements almost complete spec of CommonLisp's format function.

Gauche: output may be a port, #t, or #f. Recognizes ~s, ~a, ~d, ~b, ~o, ~x. Recognizes formatting parameters compatible to CommonLisp. output can be omitted.

STk: output may be a port, #t or #f. Recognizes ~s, ~a, without any formatting parameters.

SRFI-48: output may be a port, #t or #f. Recognizes ~s, ~a, ~w, ~d, ~x, ~o, ~b, ~c, ~y, ~?, ~k, ~f, ~~, ~%, ~t, ~&, ~_, ~h. ~f recognizes formatting parameters. ouptut can be omitted.

[procedure] format format-spec obj ...

SRFI-28: returns a formatted string. ~a, ~s, ~% and ~~ is defined. SRFI-29 adds ~@*.

Supported Fomat Directives

• o: supported
• x: not supported
• @: recognize format parameter

See Also

Library:Fmt: Alex Shinn's combinator formatting library.