1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the GNU Library General Public License, with *)
(* the special exception on linking described in file ../LICENSE. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(** Formatted output 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 or two conversion
character. The conversion characters and their meanings are:
- [d], [i], [n], or [N]: 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.
- [o]: convert an integer argument to unsigned octal.
- [s]: insert a string argument.
- [S]: insert a string argument in Caml syntax (double quotes, escapes).
- [c]: insert a character argument.
- [C]: insert a character argument in Caml syntax (single quotes, escapes).
- [f]: convert a floating-point argument to decimal notation,
in the style [dddd.ddd].
- [F]: convert a floating-point argument in Caml syntax ([dddd.ddd]
with a mandatory [.]).
- [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]
- [b]: convert a boolean argument (for backward compatibility; do not
use in new programs).
- [ld], [li], [lu], [lx], [lX], [lo]: convert an [int32] argument to
the format specified by the second letter (decimal, hexadecimal, etc).
- [nd], [ni], [nu], [nx], [nX], [no]: convert a [nativeint] argument to
the format specified by the second letter.
- [Ld], [Li], [Lu], [Lx], [LX], [Lo]: convert an [int64] argument to
the format specified by the second letter.
- [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].
- [!]: take no argument and flush the output.
- [%]: take no argument and output one [%] character.
The optional flags include:
- [-]: left-justify the output (default is right justification).
- [0]: for numerical conversions, pad with zeroes instead of spaces.
- [+]: for numerical conversions, prefix number with a [+] sign if positive.
- space: for numerical conversions, prefix number with a space if positive.
- [#]: request an alternate formatting style for numbers.
The field widths are composed of an optional integer literal
indicating the minimal width of the result, possibly followed by
a dot [.] and another integer literal indicating how many digits
follow the decimal point in the [%f], [%e], and [%E] conversions.
For instance, [%6d] prints an integer, prefixing it with spaces to
fill at least 6 characters; and [%.4f] prints a float with 4
fractional digits. Each or both of the integer literals can also be
specified as a [*], in which case an extra integer argument is taken
to specify the corresponding width or precision.
Warning: if too few arguments are provided,
for instance because the [printf] function is partially
applied, the format is immediately printed up to
the conversion of the first missing argument; printing
will then resume when the missing arguments are provided.
For example, [List.iter (printf "x=%d y=%d " 1) [2;3]]
prints [x=1 y=2 3] instead of the expected
[x=1 y=2 x=1 y=3]. To get the expected behavior, do
[List.iter (fun y -> printf "x=%d y=%d " 1 y) [2;3]]. *)
val printf : ('a, out_channel, unit) format -> 'a
(** Same as {!Printf.fprintf}, but output on [stdout]. *)
val eprintf : ('a, out_channel, unit) format -> 'a
(** Same as {!Printf.fprintf}, but output on [stderr]. *)
val sprintf : ('a, unit, string) format -> 'a
(** Same as {!Printf.fprintf}, but instead of printing on an output channel,
return a string containing the result of formatting
the arguments. *)
val bprintf : Buffer.t -> ('a, Buffer.t, unit) format -> 'a
(** Same as {!Printf.fprintf}, but instead of printing on an output channel,
append the formatted arguments to the given extensible buffer
(see module {!Buffer}). *)
val kprintf : (string -> 'a) -> ('b, unit, string, 'a) format4 -> 'b
(** [kprintf k format arguments] is the same as [sprintf format arguments],
except that the resulting string is passed as argument to [k]; the
result of [k] is then returned as the result of [kprintf]. *)
(**/**)
(* For system use only. Don't call directly. *)
val scan_format :
string -> int -> (string -> int -> 'a) -> ('b -> 'c -> int -> 'a) ->
('e -> int -> 'a) -> (int -> 'a) -> 'a
|
