Returns #t, #f or a string; has side effect of printing according to FORMAT-STRING. If DESTINATION is #t, the output is to the current output port and #t is returned. If DESTINATION is #f, a formatted string is returned as the result of the call. If DESTINATION is a string, DESTINATION is regarded as the format string; FORMAT-STRING is then the first argument and the output is returned as a string. If DESTINATION is a number, the output is to the value of (current-error-port). Otherwise DESTINATION must be an output port and #t is returned.
FORMAT-STRING must be a string. In case of a formatting error format returns #f and prints a message on the value of (current-error-port). Characters are output as if the string were output by the display function with the exception of those prefixed by a tilde (~). For a detailed description of the FORMAT-STRING syntax please consult a Common LISP format reference manual. A list of all supported, non-supported and extended directives can be found in format.txt.
This unit uses definitions from the extras unit.
format implements SRFI-2823
23 http//srfi.schemers.org/srfi-28/srfi-28.html