Module type Param.S
Command.Param
is intended to be used with the [%map_open]
syntax defined in ppx_let
, like so:
let command =
Command.basic ~summary:"..."
[%map_open
let count = anon ("COUNT" %: int)
and port = flag "port" (optional int) ~doc:"N listen on this port"
and person = person_param
in
(* ... Command-line validation code, if any, goes here ... *)
fun () ->
(* The body of the command *)
do_stuff count port person
]
One can also use [%map_open]
to define composite command line parameters, like person_param
in the previous snippet:
type person = { name : string; age : int }
let person_param : person Command.Param.t =
[%map_open
let name = flag "name" (required string) ~doc:"X name of the person"
and age = flag "age" (required int) ~doc:"N how many years old"
in
{name; age}
]
The right-hand sides of [%map_open]
definitions have Command.Param
in scope.
Alternatively, you can say:
let open Foo.Let_syntax in
[%map_open
let x ...
]
if Foo
follows the same conventions as Command.Param
.
See example/command/main.ml for more examples.
include Core_kernel__.Import.Applicative.S with type 'a t := 'a t
val apply : ('a -> 'b) t -> 'a t -> 'b t
val map2 : 'a t -> 'b t -> f:('a -> 'b -> 'c) -> 'c t
val map3 : 'a t -> 'b t -> 'c t -> f:('a -> 'b -> 'c -> 'd) -> 'd t
val all : 'a t list -> 'a list t
val all_unit : unit t list -> unit t
module Applicative_infix : Base__.Applicative_intf.Applicative_infix with type 'a t := 'a t
Various internal values
val help : Core_kernel__.Import.string Core_kernel.Lazy.t t
The help text for the command.
val path : Core_kernel__.Import.string Core_kernel__.Import.list t
The subcommand path of the command.
val args : Core_kernel__.Import.string Core_kernel__.Import.list t
The arguments passed to the command.
val flag : ?aliases:Core_kernel__.Import.string Core_kernel__.Import.list -> ?full_flag_required:Core_kernel__.Import.unit -> Core_kernel__.Import.string -> 'a Flag.t -> doc:Core_kernel__.Import.string -> 'a t
flag name spec ~doc
specifies a command that, among other things, takes a flag namedname
on its command line.doc
indicates the meaning of the flag.All flags must have a dash at the beginning of the name. If
name
is not prefixed by "-", it will be normalized to"-" ^ name
.Unless
full_flag_required
is used, one doesn't have to passname
exactly on the command line, but only an unambiguous prefix ofname
(i.e., a prefix which is not a prefix of any other flag's name).NOTE: the
doc
for a flag which takes an argument should be of the formarg_name ^ " " ^ description
wherearg_name
describes the argument anddescription
describes the meaning of the flag.NOTE: flag names (including aliases) containing underscores will be rejected. Use dashes instead.
NOTE: "-" by itself is an invalid flag name and will be rejected.
val flag_optional_with_default_doc : ?aliases:Core_kernel__.Import.string Core_kernel__.Import.list -> ?full_flag_required:Core_kernel__.Import.unit -> Core_kernel__.Import.string -> 'a Arg_type.t -> ('a -> Core_kernel.Sexp.t) -> default:'a -> doc:Core_kernel__.Import.string -> 'a t
flag_optional_with_default_doc name arg_type sexp_of_default ~default ~doc
is a shortcut forflag
, where:- The
Flag.t
isoptional_with_default default arg_type
- The
doc
is passed through with an explanation of what the default value appended.
- The
val anon : 'a Anons.t -> 'a t
anon spec
specifies a command that, among other things, takes the anonymous arguments specified byspec
.
module If_nothing_chosen : sig ... end
val choose_one : 'a Core_kernel__.Import.option t Core_kernel__.Import.list -> if_nothing_chosen:('a, 'b) If_nothing_chosen.t -> 'b t
choose_one clauses ~if_nothing_chosen
expresses a sum type. It raises if more than one ofclauses
isSome _
. Whenif_nothing_chosen = `Raise
, it also raises if none ofclauses
isSome _
.
val and_arg_names : 'a t -> ('a * Core_kernel__.Import.string Core_kernel__.Import.list) t
and_arg_names t
returns both the value oft
and the names of the arguments that went intot
. Useful for errors that reference multiple params.
val and_arg_name : 'a t -> ('a * Core_kernel__.Import.string) t
Like
and_arg_names
, but asserts that there is exactly one name.