package extlib

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This module contains various standard options.

Flag options
val store_const : ?default:'a -> 'a -> 'a Opt.t

store_const ?default const returns a flag option which stores the constant value const when the option is encountered on the command line.

val store_true : unit -> bool Opt.t

store_true () returns an option which is set to true when it is encountered on the command line. The default value is false.

val store_false : unit -> bool Opt.t

store_false () returns an option which is set to false when it is encountered on the command line. The default value is true.

val count_option : ?dest:int Pervasives.ref -> ?increment:int -> unit -> int Opt.t

Create a counting option which increments its value each time the option is encountered on the command line.

  • parameter increment

    Increment to add to the option value each time the option is encountered.

  • parameter dest

    Reference to the option value. Useful for making options like '--quiet' and '--verbose' sharing a single value.

  • returns

    the newly created option.

val incr_option : ?dest:int Pervasives.ref -> unit -> int Opt.t

Exactly identical to count_option ~dest:dest ~increment:1 ().

val decr_option : ?dest:int Pervasives.ref -> unit -> int Opt.t

Exactly identical to count_option ~dest:dest ~increment:(-1) ().

Value options
val int_option : ?default:int -> ?metavar:string -> unit -> int Opt.t

int_option ?default ?metavar () returns an option which takes a single integer argument. If ~default is given it is the default value returned when the option has not been encountered on the command line.

val float_option : ?default:float -> ?metavar:string -> unit -> float Opt.t

See OptParse.StdOpt.int_option.

val str_option : ?default:string -> ?metavar:string -> unit -> string Opt.t

See OptParse.StdOpt.int_option.

Callback options
val int_callback : ?metavar:string -> (int -> unit) -> unit Opt.t

int_callback ?metavar f returns an option which takes a single integer argument and calls f with that argument when encountered on the command line.

val float_callback : ?metavar:string -> (float -> unit) -> unit Opt.t

See OptParse.StdOpt.int_callback.

val str_callback : ?metavar:string -> (string -> unit) -> unit Opt.t

See OptParse.StdOpt.int_callback.

Special options
val help_option : unit -> 'a Opt.t

help_option () returns the standard help option which displays a usage message and exits the program when encountered on the command line.

val version_option : (unit -> string) -> 'a Opt.t

version_option f returns the standard version option which displays the string returned by f () (and nothing else) on standard output and exits.