58 lines
2.9 KiB
OCaml
58 lines
2.9 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Caml Special Light *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1995 Institut National de Recherche en Informatique et *)
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(* Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Module [Arg]: parsing of command line arguments *)
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(* This module provides a general mechanism for extracting options and
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arguments from the command line to the program. *)
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(* Syntax of command lines:
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A keyword is a character string starting with a [-].
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An option is a keyword alone or followed by an argument.
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There are six types of keywords: [Unit], [String], [Int], and [Float].
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[Unit], [Set_flag] and [Clear_flag] keywords do not take an argument.
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[String], [Int], and [Float] keywords take the following word on the
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command line as an argument.
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Arguments not preceded by a keyword are called anonymous arguments. *)
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(* Examples ([cmd] is assumed to be the command name):
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- [cmd -flag ](a unit option)
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- [cmd -int 1 ](an int option with argument [1])
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- [cmd -string foobar ](a string option with argument ["foobar"])
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- [cmd -float 12.34 ](a float option with argument [12.34])
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- [cmd 1 2 3 ](three anonymous arguments: ["1"], ["2"], and ["3"])
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*)
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type spec =
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Unit of (unit -> unit) (* Call the function with no argument *)
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| Set of bool ref (* Set the reference to true *)
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| Clear of bool ref (* Set the reference to false *)
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| String of (string -> unit) (* Call the function with a string argument *)
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| Int of (int -> unit) (* Call the function with an int argument *)
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| Float of (float -> unit) (* Call the function with a float argument *)
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(* The concrete type describing the behavior associated
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with a keyword. *)
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val parse : (string * spec) list -> (string -> unit) -> unit
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(* [parse speclist anonfun] parses the command line,
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calling the functions in [speclist] whenever appropriate,
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and [anonfun] on anonymous arguments.
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The functions are called in the same order as they appear
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on the command line.
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The strings in the [(string * spec) list] are keywords and must
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start with a [-], else they are ignored. *)
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exception Bad of string
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(* Functions in [speclist] or [anonfun] can raise [Bad] with
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an error message to reject invalid arguments. *)
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