include module type of struct include Stdlib end
Exceptions
Raise the given exception value
Sourceval raise_notrace : exn -> 'a 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.
Sourceexception Match_failure of string * int * int Exception raised when none of the cases of a pattern-matching apply. The arguments are the location of the match keyword in the source code (file name, line number, column number).
Sourceexception Assert_failure of string * int * int Exception raised when an assertion fails. The arguments are the location of the assert keyword in the source code (file name, line number, column number).
Sourceexception Invalid_argument of string Exception raised by library functions to signal that the given arguments do not make sense. The string gives some information to the programmer. As a general rule, this exception should not be caught, it denotes a programming error and the code should be modified not to trigger it.
Sourceexception Failure of string Exception raised by library functions to signal that they are undefined on the given arguments. The string is meant to give some information to the programmer; you must not pattern match on the string literal because it may change in future versions (use Failure _ instead).
Exception raised by search functions when the desired object could not be found.
Exception raised by the garbage collector when there is insufficient memory to complete the computation. (Not reliable for allocations on the minor heap.)
Sourceexception Stack_overflow Exception raised by the bytecode interpreter when the evaluation stack reaches its maximal size. This often indicates infinite or excessively deep recursion in the user's program.
Before 4.10, it was not fully implemented by the native-code compiler.
Sourceexception Sys_error of string Exception raised by the input/output functions to report an operating system error. The string is meant to give some information to the programmer; you must not pattern match on the string literal because it may change in future versions (use Sys_error _ instead).
Exception raised by input functions to signal that the end of file has been reached.
Sourceexception Division_by_zero Exception raised by integer division and remainder operations when their second argument is zero.
Sourceexception Sys_blocked_io A special case of Sys_error raised when no I/O is possible on a non-blocking I/O channel.
Sourceexception Undefined_recursive_module of string * int * int Exception raised when an ill-founded recursive module definition is evaluated. The arguments are the location of the definition in the source code (file name, line number, column number).
Comparisons
Boolean operations
Sourceval (&&) : 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. Right-associative operator, see Ocaml_operators for more information.
Sourceval (||) : 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. Right-associative operator, see Ocaml_operators for more information.
Debugging
__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.
__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.
Sourceval __POS__ : string * int * int * int __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.
Sourceval __FUNCTION__ : string __FUNCTION__ returns the name of the current function or method, including any enclosing modules or classes.
Sourceval __LOC_OF__ : 'a -> string * 'a __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".
Sourceval __LINE_OF__ : 'a -> int * 'a __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.
Sourceval __POS_OF__ : 'a -> (string * int * int * int) * 'a __POS_OF__ expr returns a pair (loc,expr), 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.
Composition operators
Sourceval (|>) : 'a -> ('a -> 'b) -> 'b Reverse-application operator: x |> f |> g is exactly equivalent to g (f (x)). Left-associative operator, see Ocaml_operators for more information.
Sourceval (@@) : ('a -> 'b) -> 'a -> 'b Application operator: g @@ f @@ x is exactly equivalent to g (f (x)). Right-associative operator, see Ocaml_operators for more information.
Integer arithmetic
Integers are Sys.int_size bits wide. All operations are taken modulo 2Sys.int_size. They do not fail on overflow.
Unary negation. You can also write - e instead of ~- e. Unary operator, see Ocaml_operators for more information.
Unary addition. You can also write + e instead of ~+ e. Unary operator, see Ocaml_operators for more information.
Sourceval (+) : int -> int -> int Integer addition. Left-associative operator, see Ocaml_operators for more information.
Sourceval (-) : int -> int -> int Integer subtraction. Left-associative operator, , see Ocaml_operators for more information.
Sourceval (*) : int -> int -> int Integer multiplication. Left-associative operator, see Ocaml_operators for more information.
Sourceval (/) : int -> int -> int Integer division. 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). Left-associative operator, see Ocaml_operators for more information.
Sourceval (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. Left-associative operator, see Ocaml_operators for more information.
abs x is the absolute value of x. On min_int this is min_int itself and thus remains negative.
The greatest representable integer.
The smallest representable integer.
Bitwise operations
Sourceval (land) : int -> int -> int Bitwise logical and. Left-associative operator, see Ocaml_operators for more information.
Sourceval (lor) : int -> int -> int Bitwise logical or. Left-associative operator, see Ocaml_operators for more information.
Sourceval (lxor) : int -> int -> int Bitwise logical exclusive or. Left-associative operator, see Ocaml_operators for more information.
Bitwise logical negation.
Sourceval (lsl) : int -> int -> int n lsl m shifts n to the left by m bits. The result is unspecified if m < 0 or m > Sys.int_size. Right-associative operator, see Ocaml_operators for more information.
Sourceval (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 > Sys.int_size. Right-associative operator, see Ocaml_operators for more information.
Sourceval (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 > Sys.int_size. Right-associative operator, see Ocaml_operators for more information.
Floating-point arithmetic
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, basic arithmetic operations (+., -., *., /.) with nan as an argument return nan, ...
Sourceval (~-.) : float -> float Unary negation. You can also write -. e instead of ~-. e. Unary operator, see Ocaml_operators for more information.
Sourceval (~+.) : float -> float Unary addition. You can also write +. e instead of ~+. e. Unary operator, see Ocaml_operators for more information.
Sourceval (+.) : float -> float -> float Floating-point addition. Left-associative operator, see Ocaml_operators for more information.
Sourceval (-.) : float -> float -> float Floating-point subtraction. Left-associative operator, see Ocaml_operators for more information.
Sourceval (*.) : float -> float -> float Floating-point multiplication. Left-associative operator, see Ocaml_operators for more information.
Sourceval (/.) : float -> float -> float Floating-point division. Left-associative operator, see Ocaml_operators for more information.
Sourceval (**) : float -> float -> float Exponentiation. Right-associative operator, see Ocaml_operators for more information.
Sourceval sqrt : float -> float Sourceval exp : float -> float Sourceval log : float -> float Sourceval log10 : float -> float Sourceval expm1 : float -> float expm1 x computes exp x -. 1.0, giving numerically-accurate results even if x is close to 0.0.
Sourceval log1p : float -> float log1p x computes log(1.0 +. x) (natural logarithm), giving numerically-accurate results even if x is close to 0.0.
Sourceval cos : float -> float Cosine. Argument is in radians.
Sourceval sin : float -> float Sine. Argument is in radians.
Sourceval tan : float -> float Tangent. Argument is in radians.
Sourceval 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.
Sourceval 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.
Sourceval atan : float -> float Arc tangent. Result is in radians and is between -pi/2 and pi/2.
Sourceval 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.
Sourceval hypot : float -> float -> float 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. If one of x or y is infinite, returns infinity even if the other is nan.
Sourceval cosh : float -> float Hyperbolic cosine. Argument is in radians.
Sourceval sinh : float -> float Hyperbolic sine. Argument is in radians.
Sourceval tanh : float -> float Hyperbolic tangent. Argument is in radians.
Sourceval acosh : float -> float Hyperbolic arc cosine. The argument must fall within the range [1.0, inf]. Result is in radians and is between 0.0 and inf.
Sourceval asinh : float -> float Hyperbolic arc sine. The argument and result range over the entire real line. Result is in radians.
Sourceval atanh : float -> float Hyperbolic arc tangent. The argument must fall within the range [-1.0, 1.0]. Result is in radians and ranges over the entire real line.
Sourceval 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.
Sourceval 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.
Sourceval abs_float : float -> float abs_float f returns the absolute value of f.
Sourceval copysign : float -> float -> 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.
Sourceval 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.
Sourceval 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.
Sourceval ldexp : float -> int -> float ldexp x n returns x *. 2 ** n.
Sourceval modf : float -> float * float modf f returns the pair of the fractional and integral part of f.
Sourceval float : int -> float Same as Stdlib.float_of_int.
Sourceval float_of_int : int -> float Convert an integer to floating-point.
Sourceval truncate : float -> int Same as Stdlib.int_of_float.
Sourceval 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.
Sourceval neg_infinity : 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, unless otherwise specified in IEEE 754 standard. As for floating-point comparisons, =, <, <=, > and >= return false and <> returns true if one or both of their arguments is nan.
nan is a quiet NaN since 5.1; it was a signaling NaN before.
The largest positive finite value of type float.
The smallest positive, non-zero, non-denormalized value of type float.
Sourceval epsilon_float : float The difference between 1.0 and the smallest exactly representable floating-point number greater than 1.0.
Sourcetype fpclass = fpclass = | FP_normalNormal number, none of the below
| FP_subnormalNumber very close to 0.0, has reduced precision
| FP_zero| FP_infiniteNumber is positive or negative infinity
| FP_nanNot a number: result of an undefined operation
The five classes of floating-point numbers, as determined by the Stdlib.classify_float function.
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.
Character operations
More character operations are provided in module Char.
Sourceval int_of_char : char -> int Return the ASCII code of the argument.
Sourceval char_of_int : int -> char Return the character with the given ASCII code.
Unit operations
String conversion functions
Sourceval string_of_bool : bool -> string Return the string representation of a boolean. As the returned values may be shared, the user should not modify them directly.
Sourceval bool_of_string_opt : string -> bool option Convert the given string to a boolean.
Return None if the string is not "true" or "false".
Sourceval string_of_int : int -> string Return the string representation of an integer, in decimal.
Sourceval int_of_string_opt : string -> int option Convert the given string to an integer. The string is read in decimal (by default, or if the string begins with 0u), in hexadecimal (if it begins with 0x or 0X), in octal (if it begins with 0o or 0O), or in binary (if it begins with 0b or 0B).
The 0u prefix reads the input as an unsigned integer in the range [0, 2*max_int+1]. If the input exceeds max_int it is converted to the signed integer min_int + input - max_int - 1.
The _ (underscore) character can appear anywhere in the string and is ignored.
Return None 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.
Sourceval string_of_float : float -> string Return a string representation of a floating-point number.
This conversion can involve a loss of precision. For greater control over the manner in which the number is printed, see Printf.
Sourceval float_of_string_opt : string -> float option Convert the given string to a float. The string is read in decimal (by default) or in hexadecimal (marked by 0x or 0X).
The format of decimal floating-point numbers is [-] dd.ddd (e|E) [+|-] dd , where d stands for a decimal digit.
The format of hexadecimal floating-point numbers is [-] 0(x|X) hh.hhh (p|P) [+|-] dd , where h stands for an hexadecimal digit and d for a decimal digit.
In both cases, at least one of the integer and fractional parts must be given; the exponent part is optional.
The _ (underscore) character can appear anywhere in the string and is ignored.
Depending on the execution platforms, other representations of floating-point numbers can be accepted, but should not be relied upon.
Return None if the given string is not a valid representation of a float.
Pair operations
Sourceval fst : ('a * 'b) -> 'a Return the first component of a pair.
Sourceval snd : ('a * 'b) -> 'b Return the second component of a pair.
List operations
More list operations are provided in module List.
Sourceval (@) : 'a list -> 'a list -> 'a list l0 @ l1 appends l1 to l0. Same function as List.append. Right-associative operator, see Ocaml_operators for more information.
Note: all input/output functions can raise Sys_error when the system calls they invoke fail.
The type of input channel.
The type of output channel.
The standard input for the process.
The standard output for the process.
The standard error output for the process.
Output functions on standard output
Output functions on standard error
General output functions
Sourcetype open_flag = open_flag = | Open_rdonly| Open_wronly| Open_appendopen for appending: always write at end of file.
| Open_creatcreate the file if it does not exist.
| Open_truncempty the file if it already exists.
| Open_exclfail if Open_creat and the file already exists.
| Open_binaryopen in binary mode (no conversion).
| Open_textopen in text mode (may perform conversions).
| Open_nonblockopen in non-blocking mode.
Opening modes for Stdlib.open_out_gen and Stdlib.open_in_gen.
Return the current reading position for the given channel. For files opened in text mode under Windows, the returned position is approximate (owing to end-of-line conversion); in particular, saving the current position with pos_in, then going back to this position using seek_in will not work. For this programming idiom to work reliably and portably, the file must be opened in binary mode.
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.
Operations on large files
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
Sourcetype 'a ref = 'a ref = {mutable contents : 'a;
} The type of references (mutable indirection cells) containing a value of type 'a.
Return a fresh reference containing the given value.
!r returns the current contents of reference r. Equivalent to fun r -> r.contents. Unary operator, see Ocaml_operators for more information.
r := a stores the value of a in reference r. Equivalent to fun r v -> r.contents <- v. Right-associative operator, see Ocaml_operators for more information.
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.
Result type
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:
- conversions specifications, introduced by the special character
'%' followed by one or more characters specifying what kind of argument to read or print, - formatting indications, introduced by the special character
'@' followed by one or more characters specifying how to read or print the argument, - plain characters that are regular characters with usual lexical conventions. Plain characters specify string literals to be read in the input or printed in the output.
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.
Sourceval (^^) :
('a, 'b, 'c, 'd, 'e, 'f) format6 ->
('f, 'b, 'c, 'e, 'g, 'h) format6 ->
('a, 'b, 'c, 'd, 'g, 'h) format6 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. Right-associative operator, see Ocaml_operators for more information.
Program termination
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. The callbacks registered with Domain.at_exit are called followed by those registered with Stdlib.at_exit.
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.
Sourceval 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 does any of the following:
- executes
Stdlib.exit - terminates, either normally or because of an uncaught exception
- executes the C function
caml_shutdown. The functions are called in 'last in, first out' order: the function most recently added with at_exit is called first.
Standard library modules