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Version: 2.2.5

Programming

assert​

Ensure that a condition is satisfied (raise error.assertion exception otherwise).

Type:

(bool) -> unit

Arguments:

  • (unlabeled) (of type bool): Condition which should be satisfied.

error.on_error​

Register a callback to monitor errors raised during the execution of the program. The callback is allow to re-raise a different error if needed.

Type:

(((error
   .{
     kind : string,
     message : string,
     trace : [
              {
                position_end : 
                {character_offset : int, filename : string, line_number : int
                },
                position_start : 
                {character_offset : int, filename : string, line_number : int
                },
                to_string : (?prefix : string) -> string
              }]
   }) -> unit)) -> unit

Arguments:

  • (unlabeled) (of type (error .{ kind : string, message : string, trace : [ { position_end : {character_offset : int, filename : string, line_number : int }, position_start : {character_offset : int, filename : string, line_number : int }, to_string : (?prefix : string) -> string }] }) -> unit)

error.raise​

Raise an error.

Type:

(error, ?string) -> 'a

Arguments:

  • (unlabeled) (of type error): Error kind.
  • (unlabeled) (of type string, which defaults to ""): Description of the error.

error.register​

Register an error of the given kind

Type:

(string) -> error

Arguments:

  • (unlabeled) (of type string): Kind of the error

Methods:

  • kind (of type string): Error kind.
  • message (of type string): Error message.
  • trace (of type [ { position_end : {character_offset : int, filename : string, line_number : int }, position_start : {character_offset : int, filename : string, line_number : int }, to_string : (?prefix : string) -> string }]): Error stacktrace.

failwith​

Major failure.

Type:

(string) -> 'a

Arguments:

  • (unlabeled) (of type string): Explanation about the failure.

fst​

Get the first component of a pair.

Type:

(('a * 'b)) -> 'a

Arguments:

  • (unlabeled) (of type 'a * 'b)

ignore​

Convert anything to unit, preventing warnings.

Type:

('a) -> unit

Arguments:

  • (unlabeled) (of type 'a)

memoize​

Memoize the result of a function, making sure it is only executed once.

Type:

((() -> 'a)) -> () -> 'a where 'a is an orderable type

Arguments:

  • (unlabeled) (of type () -> 'a where 'a is an orderable type)

null​

Create a nullable value.

Type:

(?'a?) -> 'a?

Arguments:

  • (unlabeled) (of type 'a?, which defaults to null): Value to make nullable.

null.case​

Return a result dending on whether a value is nothing or not.

Type:

('a?, (() -> 'b), (('a) -> 'b)) -> 'b

Arguments:

  • (unlabeled) (of type 'a?): Value to reason by case analysis on.
  • (unlabeled) (of type () -> 'b): Value to return in case we have nothing.
  • (unlabeled) (of type ('a) -> 'b): Value to return in case we have something.

null.default​

Return a result dending on whether a value is nothing or not.

Type:

('a?, (() -> 'a)) -> 'a

Arguments:

  • (unlabeled) (of type 'a?): Value to reason by case analysis on.
  • (unlabeled) (of type () -> 'a): Value to return in case we have nothing.

null.defined​

Determine whether a nullable value is not null.

Type:

('a?) -> bool

Arguments:

  • (unlabeled) (of type 'a?)

null.find​

Find the first element of a list for which the image of the function is not null. Raises error.not_found if not element is found and no default value was specified.

Type:

(?default : 'a??, (('b) -> 'a?), ['b]) -> 'a?

Arguments:

  • default (of type 'a??, which defaults to null): Returned value when no element is found.
  • (unlabeled) (of type ('b) -> 'a?): Function.
  • (unlabeled) (of type ['b]): List.

null.get​

Get the value of a nullable. Raises error.not_found if the value is null and no default value was specified.

Type:

(?default : 'a?, 'a?) -> 'a

Arguments:

  • default (of type 'a?, which defaults to null): Returned value when the value is null.
  • (unlabeled) (of type 'a?)

null.map​

Apply a function on a nullable value if it is not null, and return null otherwise.

Type:

((('a) -> 'b?), 'a?) -> 'b?

Arguments:

  • (unlabeled) (of type ('a) -> 'b?)
  • (unlabeled) (of type 'a?)

null.to_list​

Convert a nullable value to a list containing zero or one element depending on whether the value is null or not.

Type:

('a?) -> ['a]

Arguments:

  • (unlabeled) (of type 'a?)

position​

Return the current position in the script

Type:

() -> unit

Methods:

  • character_offset (of type int): character offset
  • filename (of type string): filename
  • line_number (of type int): line number

predicate.activates​

Detect when a predicate becomes true.

Type:

(?init : bool, (() -> bool)) -> () -> bool

Arguments:

  • init (of type bool, which defaults to false): Detect at beginning.
  • (unlabeled) (of type () -> bool): Predicate.

predicate.at_most​

Limit the number of times a predicate is true is a row.

Type:

(int, (() -> bool)) -> () -> bool

Arguments:

  • (unlabeled) (of type int): Number of times the predicate is allowed to be true.
  • (unlabeled) (of type () -> bool): Predicate.

predicate.changes​

Detect when a predicate changes.

Type:

((() -> 'a)) -> () -> bool where 'a is an orderable type

Arguments:

  • (unlabeled) (of type () -> 'a where 'a is an orderable type): Predicate.

predicate.first​

First occurrence of a predicate.

Type:

((() -> bool)) -> () -> bool

Arguments:

  • (unlabeled) (of type () -> bool): Predicate.

predicate.once​

Become true once every time a predicate is true.

Type:

((() -> bool)) -> () -> bool

Arguments:

  • (unlabeled) (of type () -> bool): Predicate.

predicate.signal​

Predicate which is true when a signal is sent. The returned predicate has a method signal to send the signal.

Type:

() -> () -> bool

Methods:

  • signal (of type () -> unit): Send a signal.

print​

Print on standard output.

Type:

(?newline : bool, 'a) -> unit

Arguments:

  • newline (of type bool, which defaults to true): If true, a newline is added after displaying the value.
  • (unlabeled) (of type 'a)

ref​

Create a reference, i.e. a value which can be modified.

Type:

('a) -> () -> 'a

Arguments:

  • (unlabeled) (of type 'a)

Methods:

  • set (of type ('A) -> unit): Set the value of the reference.

ref.getter​

Create a getter from a reference (sometimes useful to remove the set method).

Type:

((() -> 'a).{set : ('a) -> unit}) -> () -> 'a

Arguments:

  • (unlabeled) (of type (() -> 'a).{set : ('a) -> unit})

ref.incr​

Increment a reference to an integer.

Type:

((() -> int).{set : (int) -> 'a}) -> 'a

Arguments:

  • (unlabeled) (of type (() -> int).{set : (int) -> 'a})

ref.make​

Create a reference from a pair of get / set functions.

Type:

((() -> 'a), (('a) -> unit)) -> () -> 'a

Arguments:

  • (unlabeled) (of type () -> 'a): Function to retrieve the value of the reference.
  • (unlabeled) (of type ('a) -> unit): Function to change the value of the reference.

Methods:

  • set (of type ('A) -> unit): Set the value of the reference.

ref.map​

Map functions to a reference.

Type:

((('a) -> 'b), (('b) -> 'a), (() -> 'a).{set : ('a) -> unit}) -> () -> 'b

Arguments:

  • (unlabeled) (of type ('a) -> 'b): Function to apply to the getter.
  • (unlabeled) (of type ('b) -> 'a): Function to apply to the setter.
  • (unlabeled) (of type (() -> 'a).{set : ('a) -> unit})

Methods:

  • set (of type ('A) -> unit): Set the value of the reference.

snd​

Get the second component of a pair.

Type:

(('a * 'b)) -> 'b

Arguments:

  • (unlabeled) (of type 'a * 'b)

thread.on_error​

Register the function to be called when an error of the given kind is raised in a thread. Catches all errors if first argument is null.

Type:

(error
 .{
   kind : string,
   message : string,
   trace : [
            {
              position_end : 
              {character_offset : int, filename : string, line_number : int
              },
              position_start : 
              {character_offset : int, filename : string, line_number : int
              },
              to_string : (?prefix : string) -> string
            }]
 }?,
 ((backtrace : string, error
   .{
     kind : string,
     message : string,
     trace : [
              {
                position_end : 
                {character_offset : int, filename : string, line_number : int
                },
                position_start : 
                {character_offset : int, filename : string, line_number : int
                },
                to_string : (?prefix : string) -> string
              }]
   }) -> unit)) -> unit

Arguments:

  • (unlabeled) (of type error .{ kind : string, message : string, trace : [ { position_end : {character_offset : int, filename : string, line_number : int }, position_start : {character_offset : int, filename : string, line_number : int }, to_string : (?prefix : string) -> string }] }?)
  • (unlabeled) (of type (backtrace : string, error .{ kind : string, message : string, trace : [ { position_end : {character_offset : int, filename : string, line_number : int }, position_start : {character_offset : int, filename : string, line_number : int }, to_string : (?prefix : string) -> string }] }) -> unit)

thread.pause​

Pause execution for a given amount of seconds. This freezes the calling thread and should not be used in the main streaming loop.

Type:

(float) -> unit

Arguments:

  • (unlabeled) (of type float): Number of seconds of pause.

thread.run​

Run a function in a separate thread.

Type:

(?fast : bool, ?delay : float, ?every : {float}?, (() -> unit)) -> unit

Arguments:

  • fast (of type bool, which defaults to true): Whether the thread is supposed to return quickly or not. Typically, blocking tasks (e.g. fetching data over the internet) should not be considered to be fast. When set to false its priority will be lowered below that of request resolutions and fast timeouts. This is only effective if you set a dedicated queue for fast tasks, see the "scheduler" settings for more details.
  • delay (of type float, which defaults to 0.): Delay (in seconds) after which the thread should be launched.
  • every (of type {float}?, which defaults to null): How often (in seconds) the thread should be run. If negative or null, run once.
  • (unlabeled) (of type () -> unit): Function to execute.

thread.run.recurrent​

Run a recurrent function in a separate thread.

Type:

(?fast : bool, ?delay : float, (() -> float)) -> unit

Arguments:

  • fast (of type bool, which defaults to true): Whether the thread is supposed to return quickly or not. Typically, blocking tasks (e.g. fetching data over the internet) should not be considered to be fast. When set to false its priority will be lowered below that of request resolutions and fast timeouts. This is only effective if you set a dedicated queue for fast tasks, see the "scheduler" settings for more details.
  • delay (of type float, which defaults to 0.): Delay (in sec.) after which the thread should be launched.
  • (unlabeled) (of type () -> float): Function to execute recurrently. The returned value is the delay (in sec.) in which the function should be run again (it won't be run if the value is strictly negative).

thread.when​

Execute a callback when a predicate is true. The predicate is checked every seconds and the callback is called when the predicate returns true after having been false, following the same semantics as predicate.activates.

Type:

(?fast : bool, ?init : bool, ?every : {float}, ?once : bool, ?changed : bool,
 (() -> bool), (() -> 'a)) -> unit

Arguments:

  • fast (of type bool, which defaults to true): Whether the callback is supposed to return quickly or not.
  • init (of type bool, which defaults to true): Detect at beginning.
  • every (of type {float}, which defaults to 0.5): How often (in sec.) to check for the predicate.
  • once (of type bool, which defaults to false): Execute the function only once.
  • changed (of type bool, which defaults to true): Execute the function only if the predicate was false when last checked.
  • (unlabeled) (of type () -> bool): Predicate indicating when to execute the function, typically a time interval such as {10h-10h30}.
  • (unlabeled) (of type () -> 'a): Function to execute when the predicate is true.

while​

A while loop.

Type:

({bool}, (() -> unit)) -> unit

Arguments:

  • (unlabeled) (of type {bool}): Condition guarding the loop.
  • (unlabeled) (of type () -> unit): Function to execute.