67 lines
3.6 KiB
OCaml
67 lines
3.6 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Caml Special Light *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1995 Institut National de Recherche en Informatique et *)
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(* Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Module [Printf]: formatting printing functions *)
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val fprintf: out_channel -> ('a, out_channel, unit) format -> 'a
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(* [fprintf outchan format arg1 ... argN] formats the arguments
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[arg1] to [argN] according to the format string [format],
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and outputs the resulting string on the channel [outchan].
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The format is a character string which contains two types of
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objects: plain characters, which are simply copied to the
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output channel, and conversion specifications, each of which
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causes conversion and printing of one argument.
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Conversion specifications consist in the [%] character, followed
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by optional flags and field widths, followed by one conversion
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character. The conversion characters and their meanings are:
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- [d] or [i]: convert an integer argument to signed decimal
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- [u]: convert an integer argument to unsigned decimal
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- [x]: convert an integer argument to unsigned hexadecimal,
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using lowercase letters.
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- [X]: convert an integer argument to unsigned hexadecimal,
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using uppercase letters.
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- [s]: insert a string argument
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- [c]: insert a character argument
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- [f]: convert a floating-point argument to decimal notation,
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in the style [dddd.ddd]
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- [e] or [E]: convert a floating-point argument to decimal notation,
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in the style [d.ddd e+-dd] (mantissa and exponent)
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- [g] or [G]: convert a floating-point argument to decimal notation,
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in style [f] or [e], [E] (whichever is more compact)
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- [b]: convert a boolean argument to the string [true] or [false]
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- [a]: user-defined printer. Takes two arguments and apply the first
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one to [outchan] (the current output channel) and to the second
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argument. The first argument must therefore have type
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[out_channel -> 'b -> unit] and the second ['b].
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The output produced by the function is therefore inserted
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in the output of [fprintf] at the current point.
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- [t]: same as [%a], but takes only one argument (with type
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[out_channel -> unit]) and apply it to [outchan].
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- Refer to the C library [printf] function for the meaning of
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flags and field width specifiers.
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If too few arguments are provided, printing stops just
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before converting the first missing argument. *)
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val printf: ('a, out_channel, unit) format -> 'a
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(* Same as [fprintf], but output on [std_out]. *)
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val eprintf: ('a, out_channel, unit) format -> 'a
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(* Same as [fprintf], but output on [std_err]. *)
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val sprintf: ('a, unit, string) format -> 'a
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(* Same as [printf], but return the result of formatting in a
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string. *)
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