mirage 4.6.0 · OCaml Package

The Functoria DSL allows users to describe how to create portable and flexible applications. It allows to pass application parameters easily using command-line arguments either at configure-time or at runtime.

Users of the Functoria DSL composes their application by defining a list of module implementations, specify the command-line key that are required and combine all of them together using applicative operators.

The DSL expression is then compiled into an application builder, which will, once evaluated, produced the final portable and flexible application.

Combinators

type 'a typ = 'a Type.t

The type for values representing module types.

val typ : 'a -> 'a typ

type t is a value representing the module type t.

val (@->) : 'a typ -> 'b typ -> ('a -> 'b) typ

Construct a functor type from a type and an existing functor type. This corresponds to prepending a parameter to the list of functor parameters. For example:

kv_ro @-> ip @-> kv_ro

This describes a functor type that accepts two arguments -- a kv_ro and an ip device -- and returns a kv_ro.

type 'a impl = 'a Impl.t

The type for values representing module implementations.

val ($) : ('a -> 'b) impl -> 'a impl -> 'b impl

m $ a applies the functor m to the module a.

type abstract_impl = Impl.abstract

Same as impl but with hidden type.

val dep : 'a impl -> abstract_impl

dep t is the (build-time) dependency towards t.

Keys

type 'a key = 'a Key.key

The type for configure-time command-line arguments.

type 'a runtime_arg = 'a Runtime_arg.arg

The type for runtime command-line arguments.

val runtime_arg : 
  pos:(string * int * int * int) ->
  ?packages:Package.t list ->
  string ->
  Runtime_arg.t

runtime_arg ~pos ?packages v is the runtime argument pointing to the value v. pos is expected to be __POS__. packages specifies in which opam package the value v is defined.

type abstract_key = Key.t

The type for abstract keys.

type context = Context.t

The type for keys' parsing context. See Key.context.

type 'a value = 'a Key.value

The type for values parsed from the command-line. See Key.value.

val key : 'a key -> Key.t

key k is an untyped representation of k.

val if_impl : bool value -> 'a impl -> 'a impl -> 'a impl

if_impl v impl1 impl2 is impl1 if v is resolved to true and impl2 otherwise.

val match_impl : 'b value -> default:'a impl -> ('b * 'a impl) list -> 'a impl

match_impl v cases ~default chooses the implementation amongst cases by matching the v's value. default is chosen if no value matches.

Package dependencies

For specifying opam package dependencies, the type package is used. It consists of the opam package name, the ocamlfind names, and optional lower and upper bounds. The version constraints are merged with other modules.

type package = Package.t

The type for opam packages.

type scope = Package.scope

Installation scope of a package.

val package : 
  ?scope:scope ->
  ?build:bool ->
  ?sublibs:string list ->
  ?libs:string list ->
  ?min:string ->
  ?max:string ->
  ?pin:string ->
  ?pin_version:string ->
  string ->
  package

package ~scope ~build ~sublibs ~libs ~min ~max ~pin opam is a package. Build indicates a build-time dependency only, defaults to false. The library name is by default the same as opam, you can specify ~sublibs to add additional sublibraries (e.g. ~sublibs:["mirage"] "foo" will result in the library names ["foo"; "foo.mirage"]. In case the library name is disjoint (or empty), use ~libs. Specifying both ~libs and ~sublibs leads to an invalid argument. Version constraints are given as min (inclusive) and max (exclusive). If pin is provided, a pin-depends is generated, pin_version is "dev" by default. ~scope specifies the installation location of the package.

Application Builder

Values of type impl are tied to concrete module implementation with the device and main construct. Module implementations of type job can then be registered into an application builder. The builder is in charge if parsing the command-line arguments and of generating code for the final application. See Functoria.Lib for details.

type info = Info.t

The type for build information.

val main : 
  ?pos:(string * int * int * int) ->
  ?packages:package list ->
  ?packages_v:package list value ->
  ?runtime_args:Runtime_arg.t list ->
  string ->
  'a typ ->
  'a impl

main name typ is the functor name, having the module type typ. The connect code will call <name>.start.

If packages or packages_v is set, then the given packages are installed before compiling the current application.

Devices

type 'a code = 'a Device.code

val code : 
  pos:(string * int * int * int) ->
  ('a, Format.formatter, unit, 'b code) format4 ->
  'a

type 'a device = ('a, abstract_impl) Device.t

val of_device : 'a device -> 'a impl

of_device t is the implementation device t.

val impl : 
  ?packages:package list ->
  ?packages_v:package list Key.value ->
  ?install:(Info.t -> Install.t) ->
  ?install_v:(Info.t -> Install.t Key.value) ->
  ?keys:Key.t list ->
  ?runtime_args:Runtime_arg.t list ->
  ?extra_deps:abstract_impl list ->
  ?connect:(info -> string -> string list -> 'a code) ->
  ?dune:(info -> Dune.stanza list) ->
  ?configure:(info -> unit Action.t) ->
  ?files:(info -> Fpath.t list) ->
  string ->
  'a typ ->
  'a impl

impl ~packages ~packages_v ~install ~install_v ~keys ~runtime_args ~extra_deps ~connect ~dune ~configure ~files module_name module_type is an implementation of the device constructed by the arguments. packages and packages_v are the dependencies (where packages_v is inside Key.value). install and install_v are the install instructions (used in the generated opam file), keys are the configuration-time keys, runtime_args the arguments at runtime, extra_deps are a list of extra dependencies (other implementations), connect is the code emitted for initializing the device, dune are dune stanzas added to the build rule, configure are commands executed at the configuration phase, files are files to be added to the list of generated files, module_name is the name of the device module, and module_type is the type of the module.

Jobs

type job