Wrapper around Bos which provides a "dry run" feature.

The action type

type 'a t

An action that when executed may return a value of type 'a.

val ok : 'a -> 'a t

An action that returns a value.

val error : string -> 'a t

error e is the failed action with error message e.

val errorf : ('a, Format.formatter, unit, 'b t) format4 -> 'a

errorf fmt is the failed action with error message fmt.

val map : f:('a -> 'b) -> 'a t -> 'b t

Functor instance.

val bind : f:('a -> 'b t) -> 'a t -> 'b t

Monad instance.

val seq : unit t list -> unit t

seq t runs the elements of t in sequence.

module List : sig ... end
module Infix : sig ... end
module Syntax : sig ... end


val rm : Fpath.t -> unit t

Delete a file. (see Bos.OS.File.delete)

val mkdir : Fpath.t -> bool t

Create a directory. (See Bos.OS.Dir.create

val rmdir : Fpath.t -> unit t

Remove a directory. (see Bos.OS.Dir.delete)

val with_dir : Fpath.t -> (unit -> 'a t) -> 'a t

with_dir d f runs f with d as current working directory. (See Bos.OS.Dir.with_current).

val pwd : unit -> Fpath.t t

pwd () is the current working directory. (See Bos.OS.Dir.current)

val is_file : Fpath.t -> bool t

Does a file exist? (see Bos.OS.File.exists)

val is_dir : Fpath.t -> bool t

Does a directory exist? (see Bos.OS.Dir.exists)

val size_of : Fpath.t -> int option t

size_of f is Some i if f exists and is of size i, and None if f doesn't exist.

val set_var : string -> string option -> unit t

set_var v c sets env variable c to c. (see Bos.OS.Env.set_var)

val get_var : string -> string option t

get_var v gets the value of the variable c in the environment. (see Bos.OS.Env.get)

type channel = [
  1. | `Null
  2. | `Fmt of Format.formatter

The type for channels.

val run_cmd : ?err:channel -> ?out:channel -> Bos.Cmd.t -> unit t

Run a command. By default, err is Fmt.stderr and out is Fmt.stdout. (see Bos.OS.Cmd.run)

val run_cmd_out : ?err:channel -> Bos.Cmd.t -> string t

Run a command and return its trimmed stdout. By default err is Fmt.stderr. (See Bos.OS.Cmd.run_out)

val run_cmd_cli : Bos.Cmd.t -> unit t

Run a command as a command line interface, meaning stdout and stderr remain untouched.

val write_file : Fpath.t -> string -> unit t

Write some data to a file. (see Bos.OS.File.write)

val read_file : Fpath.t -> string t

read_file f is f's contents. (see Bos.OS.File.read)

val tmp_file : ?mode:int -> Bos.OS.File.tmp_name_pat -> Fpath.t t

tmp_file pat is a tempory file built using the pattern pat. (See Bos.OS.File.tmp)

val ls : Fpath.t -> (Fpath.t -> bool) -> Fpath.t list t

ls dir is the list of files in dir.

val with_output : ?mode:int -> ?append:bool -> path:Fpath.t -> purpose:string -> (Format.formatter -> 'a) -> 'a t

Open a file with a given mode, and write some data to it through a function. (see Bos.OS.File.with_oc). purpose is used in error messages. If append is set (by default it is not), the data is appended to path.


val run : 'a t -> ('a, Rresult.R.msg) result

Run the command through Bos.

type env

The type for virtual environments.

type files = [
  1. | `Passtrough of Fpath.t
  2. | `Files of (Fpath.t * string) list
val default_exec : Bos.Cmd.t -> (string * string) option

default_exec cmd is Some ("$(<cmd>)", "").

val env : ?exec:(Bos.Cmd.t -> (string * string) option) -> ?env:(string * string) list -> ?pwd:Fpath.t -> ?files:files -> unit -> env
type 'a domain = {
  1. result : ('a, Rresult.R.msg) result;
  2. env : env;
  3. logs : string list;

The type for interpreted values.

val eq_domain : ('a -> 'a -> bool) -> 'a domain -> 'a domain -> bool

eq_domain is the equality function between domains.

val pp_domain : 'a Fmt.t -> 'a domain Fmt.t

pp_domain is the pretty-printer for domains.

val dry_run : ?env:env -> 'a t -> 'a domain

Emulate the action. This will not do IO on the actual files. Some approximation is done to determine the result of actions. files is a list of paths that are supposed to exist at the beginning. Returns:

  • the result of the action (which can be an Bos error)
  • the list of files after execution
  • a trace (list of log messages)
val dry_run_trace : ?env:env -> 'a t -> unit

Only output the trace part of dry_run.

val generated_files : ?env:env -> 'a t -> Fpath.Set.t

generated_files t is the set of files created by t. Note: this might be incomplete/incorrect in case of calls to external commands.