(***********************************************************************) (* *) (* Objective Caml *) (* *) (* Xavier Leroy, projet Cristal, INRIA Rocquencourt *) (* *) (* Copyright 1996 Institut National de Recherche en Informatique et *) (* Automatique. Distributed only by permission. *) (* *) (***********************************************************************) (* $Id$ *) (* Module [Printf]: formatting printing functions *) val fprintf: out_channel -> ('a, out_channel, unit) format -> 'a (* [fprintf outchan format arg1 ... argN] formats the arguments [arg1] to [argN] according to the format string [format], and outputs the resulting string on the channel [outchan]. The format is a character string which contains two types of objects: plain characters, which are simply copied to the output channel, and conversion specifications, each of which causes conversion and printing of one argument. Conversion specifications consist in the [%] character, followed by optional flags and field widths, followed by one conversion character. The conversion characters and their meanings are: - [d] or [i]: convert an integer argument to signed decimal - [u]: convert an integer argument to unsigned decimal - [x]: convert an integer argument to unsigned hexadecimal, using lowercase letters. - [X]: convert an integer argument to unsigned hexadecimal, using uppercase letters. - [s]: insert a string argument - [c]: insert a character argument - [f]: convert a floating-point argument to decimal notation, in the style [dddd.ddd] - [e] or [E]: convert a floating-point argument to decimal notation, in the style [d.ddd e+-dd] (mantissa and exponent) - [g] or [G]: convert a floating-point argument to decimal notation, in style [f] or [e], [E] (whichever is more compact) - [b]: convert a boolean argument to the string [true] or [false] - [a]: user-defined printer. Takes two arguments and apply the first one to [outchan] (the current output channel) and to the second argument. The first argument must therefore have type [out_channel -> 'b -> unit] and the second ['b]. The output produced by the function is therefore inserted in the output of [fprintf] at the current point. - [t]: same as [%a], but takes only one argument (with type [out_channel -> unit]) and apply it to [outchan]. - Refer to the C library [printf] function for the meaning of flags and field width specifiers. If too few arguments are provided, printing stops just before converting the first missing argument. *) val printf: ('a, out_channel, unit) format -> 'a (* Same as [fprintf], but output on [stdout]. *) val eprintf: ('a, out_channel, unit) format -> 'a (* Same as [fprintf], but output on [stderr]. *) val sprintf: ('a, unit, string) format -> 'a (* Same as [printf], but return the result of formatting in a string. *)