Module Deprecated_fcommand

module Deprecated_fcommand: Deprecated_fcommand

This module is a wrapper around Command that allows you to do away with accumulators. Here's an example:

Fcommand.cmd ~summary:"Frobnicate something" Fcommand.( flag "-n" (required int) ~doc:"N number of times to frobnicate" ++ anon (args "item" string)) (fun n items -> ...)

type ('main_in, 'main_out) t 
('main_in, 'main_out) t is a type of composable command-line specifications.

Every combinator for building t-values is polymorphic in 'main_out. In the final specification expected by cmd used to construct a command, 'main_out is specialized to unit). Various primitive specifications add parameters one at a time, so the resulting type of main is

arg1 -> ... -> argN -> unit

It may help to think of ('a, 'b) t as a function space 'a -> 'b embellished with extra information about how to parse command line, including documentation about what various flags are for.

argument parsing
type 'a parse = string -> 'a 
val string : string parse
val int : int parse
val float : float parse
val date : Core.Date.t parse
val sexp : Core.Sexp.t parse

module Flag: sig .. end
val required : 'a parse -> 'a Flag.t
val optional : 'a parse -> 'a option Flag.t
val optional_with_default : 'a -> 'a parse -> 'a Flag.t
val listed : 'a parse -> 'a list Flag.t
val no_arg : [ `Absent | `Present ] Flag.t
val no_arg_bool : bool Flag.t
val capture_remaining_command_line : string list option Flag.t
val flag : string ->
'a Flag.t ->
doc:string -> ('a -> 'm, 'm) t

anonymous arguments
module Anons: sig .. end
val (%:) : string -> 'a parse -> 'a Anons.t
val many : string -> 'a parse -> 'a list Anons.t
val maybe : 'a Anons.t -> 'a option Anons.t
val maybe_with_default : 'a -> 'a Anons.t -> 'a Anons.t
val zero : unit Anons.t
val t2 : 'a Anons.t ->
'b Anons.t -> ('a * 'b) Anons.t
val t3 : 'a Anons.t ->
'b Anons.t ->
'c Anons.t -> ('a * 'b * 'c) Anons.t
val t4 : 'a Anons.t ->
'b Anons.t ->
'c Anons.t ->
'd Anons.t ->
('a * 'b * 'c * 'd) Anons.t
val anon : 'a Anons.t -> ('a -> 'm, 'm) t

various combinators
val empty : unit -> ('a, 'a) t
val const : 'a -> ('a -> 'm, 'm) t
val either : string ->
('a option -> 'b, 'a option -> 'a option -> 'b) t
val (++) : ('m1, 'm2) t ->
('m2, 'm3) t -> ('m1, 'm3) t
spec1 ++ spec2 composes command-line specifications spec1 and spec2. Parameters specified by spec1 will come before those specified by spec2 in the eventual main function.
val either : string ->
('a option -> 'b, 'a option -> 'a option -> 'b) t
val step : ('m1 -> 'm2) -> ('m1, 'm2) t
step allows you to transform the way parameters are applied. For example, if you want labelled arguments, you can do:

Fcommand.cmd ~summary:"..." Fcommand.( step (fun main x y z -> main ~x ~y ~z) ++ flag "-x" (optional string) ~doc:"..." ++ flag "-y" (required string) ~doc:"..." ++ flag "-z" (optional int) ~doc:"..." ) (fun ~x ~y ~z -> ... )

constructing the command we've specified
val cmd : summary:string ->
?readme:(unit -> string) ->
?autocomplete:Deprecated_command.Autocomplete.t ->
?global_flags:unit Deprecated_command.Flag.t list ->
('main, unit) t -> 'main -> Deprecated_command.t