This module has exactly the same interface and implementation as INRIA's Pervasives, except that some things are deprecated in favor of Core equivalents.
Functions here are in one of four states: 1. Deprecated using @
A faster version raise which does not record the backtrace.
The Exit exception is not raised by any library function. It is
provided for use in your programs.
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.
Structural ordering functions. These functions coincide with
the usual orderings over integers, characters, strings, byte sequences
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.
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.
Return the smaller of the two arguments.
The result is unspecified if one of the arguments contains
the float value nan.
Return the greater of the two arguments.
The result is unspecified if one of the arguments contains
the float value nan.
e1 == e2 tests for physical equality of e1 and e2.
On mutable types such as references, arrays, byte sequences, 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.
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.
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.
__LOC__ returns the location at which this expression appears in
the file currently being parsed by the compiler, with the standard
error format of OCaml: "File %S, line %d, characters %d-%d"
__LOC__ returns the location at which this expression appears in
the file currently being parsed by the compiler, with the standard
error format of OCaml: "File %S, line %d, characters %d-%d"
__FILE__ returns the name of the file currently being
parsed by the compiler.
__FILE__ returns the name of the file currently being
parsed by the compiler.
__LINE__ returns the line number at which this expression
appears in the file currently being parsed by the compiler.
__LINE__ returns the line number at which this expression
appears in the file currently being parsed by the compiler.
__MODULE__ returns the module name of the file being
parsed by the compiler.
__MODULE__ returns the module name of the file being
parsed by the compiler.
__POS__ returns a tuple (file,lnum,cnum,enum), corresponding
to the location at which this expression appears in the file
currently being parsed by the compiler. file is the current
filename, lnum the line number, cnum the character position in
the line and enum the last character position in the line.
__LOC_OF__ expr returns a pair (loc, expr) where loc is the
location of expr in the file currently being parsed by the
compiler, with the standard error format of OCaml: "File %S, line
%d, characters %d-%d"
__LOC_OF__ expr returns a pair (loc, expr) where loc is the
location of expr in the file currently being parsed by the
compiler, with the standard error format of OCaml: "File %S, line
%d, characters %d-%d"
__LINE_OF__ expr returns a pair (line, expr), where line is the
line number at which the expression expr appears in the file
currently being parsed by the compiler.
__LINE_OF__ expr returns a pair (line, expr), where line is the
line number at which the expression expr appears in the file
currently being parsed by the compiler.
__POS_OF__ expr returns a pair (expr,loc), where loc is a
tuple (file,lnum,cnum,enum) corresponding to the location at
which the expression expr appears in the file currently being
parsed by the compiler. file is the current filename, lnum the
line number, cnum the character position in the line and enum
the last character position in the line.
Reverse-application operator: x |> f |> g is exactly equivalent
to g (f (x)).
Application operator: g @@ f @@ x is exactly equivalent to
g (f (x)).
Integers are 31 bits wide (or 63 bits on 64-bit processors). All operations are taken modulo 231 (or 263). They do not fail on overflow.
Unary addition. You can also write + e instead of ~+ e.
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).
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.
Return the absolute value of the argument. Note that this may be
negative if the argument is min_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.
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.
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.
OCaml'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.
Unary negation. You can also write -. e instead of ~-. e.
Unary addition. You can also write +. e instead of ~+. e.
expm1 x computes exp x -. 1.0, giving numerically-accurate results
even if x is close to 0.0.
log1p x computes log(1.0 +. x) (natural logarithm),
giving numerically-accurate results even if x is close to 0.0.
Arc cosine. The argument must fall within the range [-1.0, 1.0].
Result is in radians and is between 0.0 and pi.
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.
Arc tangent.
Result is in radians and is between -pi/2 and pi/2.
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.
hypot x y returns sqrt(x *. x + y *. y), that is, the length
of the hypotenuse of a right-angled triangle with sides of length
x and y, or, equivalently, the distance of the point (x,y)
to origin.
Hyperbolic cosine. Argument is in radians.
Hyperbolic sine. Argument is in radians.
Hyperbolic tangent. Argument is in radians.
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.
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.
copysign x y returns a float whose absolute value is that of x
and whose sign is that of y. If x is nan, returns nan.
If y is nan, returns either x or -. x, but it is not
specified which.
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.
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.
modf f returns the pair of the fractional and integral
part of f.
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.
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.
The difference between 1.0 and the smallest exactly representable
floating-point number greater than 1.0.
| (* | Normal number, none of the below | *) | |
| (* | Number very close to 0.0, has reduced precision | *) | |
| (* | Number is 0.0 or -0.0 | *) | |
| (* | Number is positive or negative infinity | *) | |
| (* | Not a number: result of an undefined operation | *) |
The five classes of floating-point numbers, as determined by the Pervasives.classify_float function.
Return the class of the given floating-point number: normal, subnormal, zero, infinite, or not a number.
More string operations are provided in module String.
More character operations are provided in module Char.
Return the character with the given ASCII code.
Raise Invalid_argument "char_of_int" if the argument is
outside the range 0--255.
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.
Return the string representation of a boolean. As the returned values may be shared, the user should not modify them directly.
Convert the given string to a boolean.
Raise Invalid_argument "bool_of_string" if the string is not
"true" or "false".
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.
Convert the given string to a float. Raise Failure "float_of_string"
if the given string is not a valid representation of a float.
More list operations are provided in module List.
Note: all input/output functions can raise Sys_error when the system
calls they invoke fail.
The standard input for the process.
The standard output for the process.
The standard error output for the process.
Print a string, followed by a newline character, on standard output and flush standard output.
Print a newline character on standard output, and flush standard output. This can be used to simulate line buffering of standard output.
Print a string, followed by a newline character on standard error and flush standard error.
Print a newline character on standard error, and flush standard error.
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.
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.
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.
| (* | open for reading. | *) | |
| (* | open for writing. | *) | |
| (* | open for appending: always write at end of file. | *) | |
| (* | create the file if it does not exist. | *) | |
| (* | empty the file if it already exists. | *) | |
| (* | fail if Open_creat and the file already exists. | *) | |
| (* | open in binary mode (no conversion). | *) | |
| (* | open in text mode (may perform conversions). | *) | |
| (* | open in non-blocking mode. | *) |
Opening modes for Pervasives.open_out_gen and Pervasives.open_in_gen.
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.
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.
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.
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.
Write the character on the given output channel.
Write the string on the given output channel.
Write the byte sequence on the given output channel.
output oc buf pos len writes len characters from byte sequence buf,
starting at offset pos, to the given output channel oc.
Raise Invalid_argument "output" if pos and len do not
designate a valid range of buf.
Same as output but take a string as argument instead of
a byte sequence.
Write one 8-bit integer (as the single character with that code) on the given output channel. The given integer is taken modulo 256.
Write one integer in binary format (4 bytes, big-endian) on the given output channel. The given integer is taken modulo 232. 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 OCaml.
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.
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.
Return the current writing position for the given channel. Does
not work on channels opened with the Open_append flag (returns
unspecified results).
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.
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.
Same as close_out, but ignore all errors.
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.
Open the named file for reading, and return a new input channel on that file, positionned at the beginning of the file.
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.
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.
Read one character from the given input channel.
Raise End_of_file if there are no more characters to read.
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.
input ic buf pos len reads up to len characters from
the given channel ic, storing them in byte sequence 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 range of buf.
really_input ic buf pos len reads len characters from channel ic,
storing them in byte sequence 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 range of buf.
really_input_string ic len reads len characters from channel ic
and returns them in a new string.
Raise End_of_file if the end of file is reached before len
characters have been read.
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.
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.
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.
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.
Return the current reading position for the given channel.
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.
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.
Same as close_in, but ignore all errors.
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.
Return a fresh reference containing the given value.
!r returns the current contents of reference r.
Equivalent to fun r -> r.contents.
r := a stores the value of a in reference r.
Equivalent to fun r v -> r.contents <- v.
Increment the integer contained in the given reference.
Equivalent to fun r -> r := succ !r.
Decrement the integer contained in the given reference.
Equivalent to fun r -> r := pred !r.
Format strings are character strings with special lexical conventions that defines the functionality of formatted input/output functions. Format strings are used to read data with formatted input functions from module Scanf and to print data with formatted output functions from modules Printf and Format.
Format strings are made of three kinds of entities:
'%'
followed by one or more characters specifying what kind of argument to
read or print,'@'
followed by one or more characters specifying how to read or print the
argument,There is an additional lexical rule to escape the special characters '%'
and '@' in format strings: if a special character follows a '%'
character, it is treated as a plain character. In other words, "%%" is
considered as a plain '%' and "%@" as a plain '@'.
For more information about conversion specifications and formatting indications available, read the documentation of modules Scanf, Printf and Format.
Format strings have a general and highly polymorphic type
('a, 'b, 'c, 'd, 'e, 'f) format6.
The two simplified types, format and format4 below are
included for backward compatibility with earlier releases of
OCaml.
The meaning of format string type parameters is as follows:
'a is the type of the parameters of the format for formatted output
functions (printf-style functions);
'a is the type of the values read by the format for formatted input
functions (scanf-style functions).'b is the type of input source for formatted input functions and the
type of output target for formatted output functions.
For printf-style functions from module Printf, 'b is typically
out_channel;
for printf-style functions from module Format, 'b is typically
Format.formatter;
for scanf-style functions from module Scanf, 'b is typically
Scanf.Scanning.in_channel.Type argument 'b is also the type of the first argument given to
user's defined printing functions for %a and %t conversions,
and user's defined reading functions for %r conversion.
'c is the type of the result of the %a and %t printing
functions, and also the type of the argument transmitted to the
first argument of kprintf-style functions or to the
kscanf-style functions.'d is the type of parameters for the scanf-style functions.'e is the type of the receiver function for the scanf-style functions.'f is the final result type of a formatted input/output function
invocation: for the printf-style functions, it is typically unit;
for the scanf-style functions, it is typically the result type of the
receiver function.Converts a format string into a string.
format_of_string s returns a format string read from the string
literal s.
Note: format_of_string can not convert a string argument that is not a
literal. If you need this functionality, use the more general
Scanf.format_from_string function.
f1 ^^ f2 catenates format strings f1 and f2. The result is a
format string that behaves as the concatenation of format strings f1 and
f2: in case of formatted output, it accepts arguments from f1, then
arguments from f2; in case of formatted input, it returns results from
f1, then results from f2.
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.
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.