Module Arg

module Arg = struct ... end 
= Unit of  (unit -> unit)
Call the function with unit argument
| Set of  bool Pervasives.ref
Set the reference to true
| Clear of  bool Pervasives.ref
Set the reference to false
| String of  (string -> unit)
Call the function with a string argument
| Int of  (int -> unit)
Call the function with an int argument
| Float of  (float -> unit)
Call the function with a float argument
| Rest of  (string -> unit)
Stop interpreting keywords and call the function with each remaining argument

Bad of  string
Functions in spec or anonfun can raise Arg.Bad with an error message to reject invalid arguments.

Simple values
current int Pervasives.ref
Position (in Sys.argv) of the argument being processed. You can change this value, e.g. to force Arg.parse to skip some arguments.


parse : keywords:(string * spec * string) list ->
others:(string -> unit) -> errmsg:string -> unit

Arg.parse speclist anonfun usage_msg parses the command line. speclist is a list of triples (key, spec, doc). key is the option keyword, it must start with a '-' character. spec gives the option type and the function to call when this option is found on the command line. doc is a one-line description of this option. anonfun is called on anonymous arguments. The functions in spec and anonfun are called in the same order as their arguments appear on the command line.
If an error occurs, Arg.parse exits the program, after printing an error message as follows: For the user to be able to specify anonymous arguments starting with a -, include for example ("-", String anonfun, doc) in speclist.
By default, parse recognizes a unit option -help, which will display usage_msg and the list of options, and exit the program. You can override this behaviour by specifying your own -help option in speclist.

usage : keywords:(string * spec * string) list -> errmsg:string -> unit
Arg.usage speclist usage_msg prints an error message including the list of valid options. This is the same message that Arg.parse prints in case of error. speclist and usage_msg are the same as for Arg.parse.