NAME¶
Pervasives - The initially opened module.
Module¶
Module Pervasives
Documentation¶
Module
Pervasives
:
sig end
The initially opened module.
This module provides the basic operations over the built-in types (numbers,
booleans, strings, exceptions, references, lists, arrays, input-output
channels, ...).
This module is automatically opened at the beginning of each compilation. All
components of this module can therefore be referred by their short name,
without prefixing them by
Pervasives .
=== Exceptions ===
val raise :
exn -> 'a
Raise the given exception value
val invalid_arg :
string -> 'a
Raise exception
Invalid_argument with the given string.
val failwith :
string -> 'a
Raise exception
Failure with the given string.
exception Exit
The
Exit exception is not raised by any library function. It is provided
for use in your programs.
=== Comparisons ===
val (=) :
'a -> 'a -> bool
e1 = e2 tests for structural equality of
e1 and
e2 .
Mutable structures (e.g. references and arrays) are equal if and only if their
current contents are structurally equal, even if the two mutable objects are
not the same physical object. Equality between functional values raises
Invalid_argument . Equality between cyclic data structures may not
terminate.
val (<>) :
'a -> 'a -> bool
Negation of
Pervasives.(=) .
val (<) :
'a -> 'a -> bool
See
Pervasives.(>=) .
val (>) :
'a -> 'a -> bool
See
Pervasives.(>=) .
val (<=) :
'a -> 'a -> bool
See
Pervasives.(>=) .
val (>=) :
'a -> 'a -> bool
Structural ordering functions. These functions coincide with the usual orderings
over integers, characters, strings and floating-point numbers, and extend them
to a total ordering over all types. The ordering is compatible with
(=)
. As in the case of
(=) , mutable structures are compared by contents.
Comparison between functional values raises
Invalid_argument .
Comparison between cyclic structures may not terminate.
val compare :
'a -> 'a -> int
compare x y returns
0 if
x is equal to
y , a
negative integer if
x is less than
y , and a positive integer if
x is greater than
y . The ordering implemented by
compare
is compatible with the comparison predicates
= ,
< and
> defined above, with one difference on the treatment of the float
value
Pervasives.nan . Namely, the comparison predicates treat
nan as different from any other float value, including itself; while
compare treats
nan as equal to itself and less than any other
float value. This treatment of
nan ensures that
compare defines
a total ordering relation.
compare applied to functional values may raise
Invalid_argument .
compare applied to cyclic structures may not terminate.
The
compare function can be used as the comparison function required by
the
Set.Make and
Map.Make functors, as well as the
List.sort and
Array.sort functions.
val min :
'a -> 'a -> 'a
Return the smaller of the two arguments. The result is unspecified if one of the
arguments contains the float value
nan .
val max :
'a -> 'a -> 'a
Return the greater of the two arguments. The result is unspecified if one of the
arguments contains the float value
nan .
val (==) :
'a -> 'a -> bool
e1 == e2 tests for physical equality of
e1 and
e2 . On
mutable types such as references, arrays, strings, records with mutable fields
and objects with mutable instance variables,
e1 == e2 is true if and
only if physical modification of
e1 also affects
e2 . On
non-mutable types, the behavior of
(==) is implementation-dependent;
however, it is guaranteed that
e1 == e2 implies
compare e1 e2 =
0 .
val (!=) :
'a -> 'a -> bool
Negation of
Pervasives.(==) .
=== Boolean operations ===
val not :
bool -> bool
The boolean negation.
val (&&) :
bool -> bool -> bool
The boolean ``and''. Evaluation is sequential, left-to-right: in
e1
&& e2 ,
e1 is evaluated first, and if it returns
false ,
e2 is not evaluated at all.
val (&) :
bool -> bool -> bool
Deprecated.
Pervasives.(&&) should be used instead.
val (||) :
bool -> bool -> bool
The boolean ``or''. Evaluation is sequential, left-to-right: in
e1 || e2
,
e1 is evaluated first, and if it returns
true ,
e2 is
not evaluated at all.
val (or) :
bool -> bool -> bool
Deprecated.
Pervasives.(||) should be used instead.
=== Integer arithmetic ===
=== Integers are 31 bits wide (or 63 bits on 64-bit processors). All
operations are taken modulo 2^{31} (or 2^{63}). They do not fail on
overflow. ===
val (~-) :
int -> int
Unary negation. You can also write
- e instead of
~- e .
val (~+) :
int -> int
Unary addition. You can also write
+ e instead of
~+ e .
Since 3.12.0
val succ :
int -> int
succ x is
x + 1 .
val pred :
int -> int
pred x is
x - 1 .
val (+) :
int -> int -> int
Integer addition.
val (-) :
int -> int -> int
Integer subtraction.
val ( * ) :
int -> int -> int
Integer multiplication.
val (/) :
int -> int -> int
Integer division. Raise
Division_by_zero if the second argument is 0.
Integer division rounds the real quotient of its arguments towards zero. More
precisely, if
x >= 0 and
y > 0 ,
x / y is the
greatest integer less than or equal to the real quotient of
x by
y . Moreover,
(- x) / y = x / (- y) = - (x / y) .
val (mod) :
int -> int -> int
Integer remainder. If
y is not zero, the result of
x mod y
satisfies the following properties:
x = (x / y) * y + x mod y and
abs(x mod y) <= abs(y) - 1 . If
y = 0 ,
x mod y raises
Division_by_zero . Note that
x mod y is negative only if
x
< 0 . Raise
Division_by_zero if
y is zero.
val abs :
int -> int
Return the absolute value of the argument. Note that this may be negative if the
argument is
min_int .
val max_int :
int
The greatest representable integer.
val min_int :
int
The smallest representable integer.
=== Bitwise operations ===
val (land) :
int -> int -> int
Bitwise logical and.
val (lor) :
int -> int -> int
Bitwise logical or.
val (lxor) :
int -> int -> int
Bitwise logical exclusive or.
val lnot :
int -> int
Bitwise logical negation.
val (lsl) :
int -> int -> int
n lsl m shifts
n to the left by
m bits. The result is
unspecified if
m < 0 or
m >= bitsize , where
bitsize is
32 on a 32-bit platform and
64 on a 64-bit
platform.
val (lsr) :
int -> int -> int
n lsr m shifts
n to the right by
m bits. This is a logical
shift: zeroes are inserted regardless of the sign of
n . The result is
unspecified if
m < 0 or
m >= bitsize .
val (asr) :
int -> int -> int
n asr m shifts
n to the right by
m bits. This is an
arithmetic shift: the sign bit of
n is replicated. The result is
unspecified if
m < 0 or
m >= bitsize .
=== Floating-point arithmetic Caml's floating-point numbers
follow the IEEE 754 standard, using double precision (64 bits)
numbers. Floating-point operations never raise an exception on
overflow, underflow, division by zero, etc. Instead, special IEEE
numbers are returned as appropriate, such as infinity for 1.0 /.
0.0, neg_infinity for -1.0 /. 0.0, and nan (``not a number'')
for 0.0 /. 0.0. These special numbers then propagate through
floating-point computations as expected: for instance, 1.0 /.
infinity is 0.0, and any arithmetic operation with nan as argument
returns nan as result. ===
val (~-.) :
float -> float
Unary negation. You can also write
-. e instead of
~-. e .
val (~+.) :
float -> float
Unary addition. You can also write
+. e instead of
~+. e .
Since 3.12.0
val (+.) :
float -> float -> float
Floating-point addition
val (-.) :
float -> float -> float
Floating-point subtraction
val ( *. ) :
float -> float -> float
Floating-point multiplication
val (/.) :
float -> float -> float
Floating-point division.
val ( ** ) :
float -> float -> float
Exponentiation.
val sqrt :
float -> float
Square root.
val exp :
float -> float
Exponential.
val log :
float -> float
Natural logarithm.
val log10 :
float -> float
Base 10 logarithm.
val expm1 :
float -> float
expm1 x computes
exp x -. 1.0 , giving numerically-accurate
results even if
x is close to
0.0 .
Since 3.12.0
val log1p :
float -> float
log1p x computes
log(1.0 +. x) (natural logarithm), giving
numerically-accurate results even if
x is close to
0.0 .
Since 3.12.0
val cos :
float -> float
Cosine. Argument is in radians.
val sin :
float -> float
Sine. Argument is in radians.
val tan :
float -> float
Tangent. Argument is in radians.
val acos :
float -> float
Arc cosine. The argument must fall within the range
[-1.0, 1.0] . Result
is in radians and is between
0.0 and
pi .
val asin :
float -> float
Arc sine. The argument must fall within the range
[-1.0, 1.0] . Result is
in radians and is between
-pi/2 and
pi/2 .
val atan :
float -> float
Arc tangent. Result is in radians and is between
-pi/2 and
pi/2 .
val atan2 :
float -> float -> float
atan2 y x returns the arc tangent of
y /. x . The signs of
x and
y are used to determine the quadrant of the result. Result
is in radians and is between
-pi and
pi .
val cosh :
float -> float
Hyperbolic cosine. Argument is in radians.
val sinh :
float -> float
Hyperbolic sine. Argument is in radians.
val tanh :
float -> float
Hyperbolic tangent. Argument is in radians.
val ceil :
float -> float
Round above to an integer value.
ceil f returns the least integer value
greater than or equal to
f . The result is returned as a float.
val floor :
float -> float
Round below to an integer value.
floor f returns the greatest integer
value less than or equal to
f . The result is returned as a float.
val abs_float :
float -> float
abs_float f returns the absolute value of
f .
val mod_float :
float -> float -> float
mod_float a b returns the remainder of
a with respect to
b
. The returned value is
a -. n *. b , where
n is the quotient
a /. b rounded towards zero to an integer.
val frexp :
float -> float * int
frexp f returns the pair of the significant and the exponent of
f
. When
f is zero, the significant
x and the exponent
n of
f are equal to zero. When
f is non-zero, they are defined by
f = x *. 2 ** n and
0.5 <= x < 1.0 .
val ldexp :
float -> int -> float
ldexp x n returns
x *. 2 ** n .
val modf :
float -> float * float
modf f returns the pair of the fractional and integral part of
f .
val float :
int -> float
Same as
Pervasives.float_of_int .
val float_of_int :
int -> float
Convert an integer to floating-point.
val truncate :
float -> int
Same as
Pervasives.int_of_float .
val int_of_float :
float -> int
Truncate the given floating-point number to an integer. The result is
unspecified if the argument is
nan or falls outside the range of
representable integers.
val infinity :
float
Positive infinity.
val neg_infinity :
float
Negative infinity.
val nan :
float
A special floating-point value denoting the result of an undefined operation
such as
0.0 /. 0.0 . Stands for ``not a number''. Any floating-point
operation with
nan as argument returns
nan as result. As for
floating-point comparisons,
= ,
< ,
<= ,
> and
>= return
false and
<> returns
true if one or both of their arguments is
nan .
val max_float :
float
The largest positive finite value of type
float .
val min_float :
float
The smallest positive, non-zero, non-denormalized value of type
float .
val epsilon_float :
float
The difference between
1.0 and the smallest exactly representable
floating-point number greater than
1.0 .
type fpclass =
| FP_normal (* Normal number, none of the below *)
| FP_subnormal (* Number very close to 0.0, has reduced precision *)
| FP_zero (* Number is 0.0 or -0.0 *)
| FP_infinite (* Number is positive or negative infinity *)
| FP_nan (* Not a number: result of an undefined operation *)
The five classes of floating-point numbers, as determined by the
Pervasives.classify_float function.
val classify_float :
float -> fpclass
Return the class of the given floating-point number: normal, subnormal, zero,
infinite, or not a number.
=== String operations More string operations are provided in
module String. ===
val (^) :
string -> string -> string
String concatenation.
=== Character operations More character operations are provided
in module Char. ===
val int_of_char :
char -> int
Return the ASCII code of the argument.
val char_of_int :
int -> char
Return the character with the given ASCII code. Raise
Invalid_argument
char_of_int if the argument is outside the range 0--255.
=== Unit operations ===
val ignore :
'a -> unit
Discard the value of its argument and return
() . For instance,
ignore(f x) discards the result of the side-effecting function
f
. It is equivalent to
f x; () , except that the latter may generate a
compiler warning; writing
ignore(f x) instead avoids the warning.
=== String conversion functions ===
val string_of_bool :
bool -> string
Return the string representation of a boolean.
val bool_of_string :
string -> bool
Convert the given string to a boolean. Raise
Invalid_argument
bool_of_string if the string is not
true or
false .
val string_of_int :
int -> string
Return the string representation of an integer, in decimal.
val int_of_string :
string -> int
Convert the given string to an integer. The string is read in decimal (by
default) or in hexadecimal (if it begins with
0x or
0X ), octal
(if it begins with
0o or
0O ), or binary (if it begins with
0b or
0B ). Raise
Failure int_of_string if the given
string is not a valid representation of an integer, or if the integer
represented exceeds the range of integers representable in type
int .
val string_of_float :
float -> string
Return the string representation of a floating-point number.
val float_of_string :
string -> float
Convert the given string to a float. Raise
Failure float_of_string if the
given string is not a valid representation of a float.
=== Pair operations ===
val fst :
'a * 'b -> 'a
Return the first component of a pair.
val snd :
'a * 'b -> 'b
Return the second component of a pair.
=== List operations More list operations are provided in module
List. ===
val (@) :
'a list -> 'a list -> 'a list
List concatenation.
=== Input/output ===
type in_channel
The type of input channel.
type out_channel
The type of output channel.
val stdin :
in_channel
The standard input for the process.
val stdout :
out_channel
The standard output for the process.
val stderr :
out_channel
The standard error output for the process.
=== Output functions on standard output ===
val print_char :
char -> unit
Print a character on standard output.
val print_string :
string -> unit
Print a string on standard output.
val print_int :
int -> unit
Print an integer, in decimal, on standard output.
val print_float :
float -> unit
Print a floating-point number, in decimal, on standard output.
val print_endline :
string -> unit
Print a string, followed by a newline character, on standard output and flush
standard output.
val print_newline :
unit -> unit
Print a newline character on standard output, and flush standard output. This
can be used to simulate line buffering of standard output.
=== Output functions on standard error ===
val prerr_char :
char -> unit
Print a character on standard error.
val prerr_string :
string -> unit
Print a string on standard error.
val prerr_int :
int -> unit
Print an integer, in decimal, on standard error.
val prerr_float :
float -> unit
Print a floating-point number, in decimal, on standard error.
val prerr_endline :
string -> unit
Print a string, followed by a newline character on standard error and flush
standard error.
val prerr_newline :
unit -> unit
Print a newline character on standard error, and flush standard error.
=== Input functions on standard input ===
val read_line :
unit -> string
Flush standard output, then read characters from standard input until a newline
character is encountered. Return the string of all characters read, without
the newline character at the end.
val read_int :
unit -> int
Flush standard output, then read one line from standard input and convert it to
an integer. Raise
Failure int_of_string if the line read is not a valid
representation of an integer.
val read_float :
unit -> float
Flush standard output, then read one line from standard input and convert it to
a floating-point number. The result is unspecified if the line read is not a
valid representation of a floating-point number.
=== General output functions ===
type open_flag =
| Open_rdonly (* open for reading. *)
| Open_wronly (* open for writing. *)
| Open_append (* open for appending: always write at end of file. *)
| Open_creat (* create the file if it does not exist. *)
| Open_trunc (* empty the file if it already exists. *)
| Open_excl (* fail if Open_creat and the file already exists. *)
| Open_binary (* open in binary mode (no conversion). *)
| Open_text (* open in text mode (may perform conversions). *)
| Open_nonblock (* open in non-blocking mode. *)
Opening modes for
Pervasives.open_out_gen and
Pervasives.open_in_gen .
val open_out :
string -> out_channel
Open the named file for writing, and return a new output channel on that file,
positionned at the beginning of the file. The file is truncated to zero length
if it already exists. It is created if it does not already exists. Raise
Sys_error if the file could not be opened.
val open_out_bin :
string -> out_channel
Same as
Pervasives.open_out , but the file is opened in binary mode, so
that no translation takes place during writes. On operating systems that do
not distinguish between text mode and binary mode, this function behaves like
Pervasives.open_out .
val open_out_gen :
open_flag list -> int -> string ->
out_channel
open_out_gen mode perm filename opens the named file for writing, as
described above. The extra argument
mode specify the opening mode. The
extra argument
perm specifies the file permissions, in case the file
must be created.
Pervasives.open_out and
Pervasives.open_out_bin
are special cases of this function.
val flush :
out_channel -> unit
Flush the buffer associated with the given output channel, performing all
pending writes on that channel. Interactive programs must be careful about
flushing standard output and standard error at the right time.
val flush_all :
unit -> unit
Flush all open output channels; ignore errors.
val output_char :
out_channel -> char -> unit
Write the character on the given output channel.
val output_string :
out_channel -> string -> unit
Write the string on the given output channel.
val output :
out_channel -> string -> int -> int ->
unit
output oc buf pos len writes
len characters from string
buf
, starting at offset
pos , to the given output channel
oc .
Raise
Invalid_argument output if
pos and
len do not
designate a valid substring of
buf .
val output_byte :
out_channel -> int -> unit
Write one 8-bit integer (as the single character with that code) on the given
output channel. The given integer is taken modulo 256.
val output_binary_int :
out_channel -> int -> unit
Write one integer in binary format (4 bytes, big-endian) on the given output
channel. The given integer is taken modulo 2^{32. The only reliable way to
read it back is through the
Pervasives.input_binary_int function. The
format is compatible across all machines for a given version of Objective
Caml.
val output_value :
out_channel -> 'a -> unit
Write the representation of a structured value of any type to a channel.
Circularities and sharing inside the value are detected and preserved. The
object can be read back, by the function
Pervasives.input_value . See
the description of module
Marshal for more information.
Pervasives.output_value is equivalent to
Marshal.to_channel with
an empty list of flags.
val seek_out :
out_channel -> int -> unit
seek_out chan pos sets the current writing position to
pos for
channel
chan . This works only for regular files. On files of other
kinds (such as terminals, pipes and sockets), the behavior is unspecified.
val pos_out :
out_channel -> int
Return the current writing position for the given channel. Does not work on
channels opened with the
Open_append flag (returns unspecified
results).
val out_channel_length :
out_channel -> int
Return the size (number of characters) of the regular file on which the given
channel is opened. If the channel is opened on a file that is not a regular
file, the result is meaningless.
val close_out :
out_channel -> unit
Close the given channel, flushing all buffered write operations. Output
functions raise a
Sys_error exception when they are applied to a closed
output channel, except
close_out and
flush , which do nothing
when applied to an already closed channel. Note that
close_out may
raise
Sys_error if the operating system signals an error when flushing
or closing.
val close_out_noerr :
out_channel -> unit
Same as
close_out , but ignore all errors.
val set_binary_mode_out :
out_channel -> bool -> unit
set_binary_mode_out oc true sets the channel
oc to binary mode: no
translations take place during output.
set_binary_mode_out oc false
sets the channel
oc to text mode: depending on the operating system,
some translations may take place during output. For instance, under Windows,
end-of-lines will be translated from
\n to
\r\n . This function
has no effect under operating systems that do not distinguish between text
mode and binary mode.
=== General input functions ===
val open_in :
string -> in_channel
Open the named file for reading, and return a new input channel on that file,
positionned at the beginning of the file. Raise
Sys_error if the file
could not be opened.
val open_in_bin :
string -> in_channel
Same as
Pervasives.open_in , but the file is opened in binary mode, so
that no translation takes place during reads. On operating systems that do not
distinguish between text mode and binary mode, this function behaves like
Pervasives.open_in .
val open_in_gen :
open_flag list -> int -> string ->
in_channel
open_in_gen mode perm filename opens the named file for reading, as
described above. The extra arguments
mode and
perm specify the
opening mode and file permissions.
Pervasives.open_in and
Pervasives.open_in_bin are special cases of this function.
val input_char :
in_channel -> char
Read one character from the given input channel. Raise
End_of_file if
there are no more characters to read.
val input_line :
in_channel -> string
Read characters from the given input channel, until a newline character is
encountered. Return the string of all characters read, without the newline
character at the end. Raise
End_of_file if the end of the file is
reached at the beginning of line.
val input :
in_channel -> string -> int -> int -> int
input ic buf pos len reads up to
len characters from the given
channel
ic , storing them in string
buf , starting at character
number
pos . It returns the actual number of characters read, between 0
and
len (inclusive). A return value of 0 means that the end of file was
reached. A return value between 0 and
len exclusive means that not all
requested
len characters were read, either because no more characters
were available at that time, or because the implementation found it convenient
to do a partial read;
input must be called again to read the remaining
characters, if desired. (See also
Pervasives.really_input for reading
exactly
len characters.) Exception
Invalid_argument input is
raised if
pos and
len do not designate a valid substring of
buf .
val really_input :
in_channel -> string -> int -> int ->
unit
really_input ic buf pos len reads
len characters from channel
ic , storing them in string
buf , starting at character number
pos . Raise
End_of_file if the end of file is reached before
len characters have been read. Raise
Invalid_argument
really_input if
pos and
len do not designate a valid
substring of
buf .
val input_byte :
in_channel -> int
Same as
Pervasives.input_char , but return the 8-bit integer representing
the character. Raise
End_of_file if an end of file was reached.
val input_binary_int :
in_channel -> int
Read an integer encoded in binary format (4 bytes, big-endian) from the given
input channel. See
Pervasives.output_binary_int . Raise
End_of_file if an end of file was reached while reading the integer.
val input_value :
in_channel -> 'a
Read the representation of a structured value, as produced by
Pervasives.output_value , and return the corresponding value. This
function is identical to
Marshal.from_channel ; see the description of
module
Marshal for more information, in particular concerning the lack
of type safety.
val seek_in :
in_channel -> int -> unit
seek_in chan pos sets the current reading position to
pos for
channel
chan . This works only for regular files. On files of other
kinds, the behavior is unspecified.
val pos_in :
in_channel -> int
Return the current reading position for the given channel.
val in_channel_length :
in_channel -> int
Return the size (number of characters) of the regular file on which the given
channel is opened. If the channel is opened on a file that is not a regular
file, the result is meaningless. The returned size does not take into account
the end-of-line translations that can be performed when reading from a channel
opened in text mode.
val close_in :
in_channel -> unit
Close the given channel. Input functions raise a
Sys_error exception when
they are applied to a closed input channel, except
close_in , which
does nothing when applied to an already closed channel. Note that
close_in may raise
Sys_error if the operating system signals an
error.
val close_in_noerr :
in_channel -> unit
Same as
close_in , but ignore all errors.
val set_binary_mode_in :
in_channel -> bool -> unit
set_binary_mode_in ic true sets the channel
ic to binary mode: no
translations take place during input.
set_binary_mode_out ic false sets
the channel
ic to text mode: depending on the operating system, some
translations may take place during input. For instance, under Windows,
end-of-lines will be translated from
\r\n to
\n . This function
has no effect under operating systems that do not distinguish between text
mode and binary mode.
=== Operations on large files ===
module LargeFile : sig end
Operations on large files. This sub-module provides 64-bit variants of the
channel functions that manipulate file positions and file sizes. By
representing positions and sizes by 64-bit integers (type
int64 )
instead of regular integers (type
int ), these alternate functions
allow operating on files whose sizes are greater than
max_int .
=== References ===
type 'a ref = {
mutable contents :
'a ;
}
The type of references (mutable indirection cells) containing a value of type
'a .
val ref :
'a -> 'a ref
Return a fresh reference containing the given value.
val (!) :
'a ref -> 'a
!r returns the current contents of reference
r . Equivalent to
fun r -> r.contents .
val (:=) :
'a ref -> 'a -> unit
r := a stores the value of
a in reference
r . Equivalent to
fun r v -> r.contents <- v .
val incr :
int ref -> unit
Increment the integer contained in the given reference. Equivalent to
fun r
-> r := succ !r .
val decr :
int ref -> unit
Decrement the integer contained in the given reference. Equivalent to
fun r
-> r := pred !r .
=== Operations on format strings ===
=== Format strings are used to read and print data using formatted input
functions in module Scanf and formatted output in modules Printf and
Format. ===
type ('a, 'b, 'c, 'd) format4 =
('a, 'b, 'c, 'c, 'c, 'd)
format6
Format strings have a general and highly polymorphic type
('a, 'b, 'c, 'd,
'e, 'f) format6 . Type
format6 is built in. The two simplified
types,
format and
format4 below are included for backward
compatibility with earlier releases of Objective Caml.
'a is the type
of the parameters of the format,
'b is the type of the first argument
given to
%a and
%t printing functions,
'c is the type of
the argument transmitted to the first argument of "kprintf"-style
functions,
'd is the result type for the "scanf"-style
functions,
'e is the type of the receiver function for the
"scanf"-style functions,
'f is the result type for the
"printf"-style function.
type ('a, 'b, 'c) format =
('a, 'b, 'c, 'c) format4
val string_of_format :
('a, 'b, 'c, 'd, 'e, 'f) format6 ->
string
Converts a format string into a string.
val format_of_string :
('a, 'b, 'c, 'd, 'e, 'f) format6 -> ('a, 'b,
'c, 'd, 'e, 'f) format6
format_of_string s returns a format string read from the string literal
s .
val (^^) :
('a, 'b, 'c, 'd, 'e, 'f) format6 -> ('f, 'b, 'c,
'e, 'g, 'h) format6 -> ('a, 'b, 'c, 'd, 'g, 'h) format6
f1 ^^ f2 catenates formats
f1 and
f2 . The result is a
format that accepts arguments from
f1 , then arguments from
f2 .
=== Program termination ===
val exit :
int -> 'a
Terminate the process, returning the given status code to the operating system:
usually 0 to indicate no errors, and a small positive integer to indicate
failure. All open output channels are flushed with flush_all. An implicit
exit 0 is performed each time a program terminates normally. An
implicit
exit 2 is performed if the program terminates early because of
an uncaught exception.
val at_exit :
(unit -> unit) -> unit
Register the given function to be called at program termination time. The
functions registered with
at_exit will be called when the program
executes
Pervasives.exit , or terminates, either normally or because of
an uncaught exception. The functions are called in ``last in, first out''
order: the function most recently added with
at_exit is called first.