src/args.bend source

src/args.bend on the hub · documented module

# shake/args: the process's arguments, each word reusable, and the values of a# spec's env vars, internal (main.bend exports them). `IO.args` answers a `&1`# list that starts with the program as invoked (bend 2.0.32 and later); the# rest of a program reads the line more than once, so `words` drops that head# and copies the rest.import Baseimport ./cli.bend as C# a &1 list copied to &2def copy(xs: List<&1, String>) -> List<&2, String>:  match xs:    case Nil{}:      Nil{}    case Con{+h, t}:      h <> copy(t)# the arguments of an IO.args line: every word after the program name, copieddef words(xs: List<&1, String>) -> List<&2, String>:  match xs:    case Nil{}:      Nil{}    case Con{_h, t}:      copy(t)# the process's arguments, without the program namedef argv() -> IO(List<&2, String>):  # noqa: L001 IO: reads argv (SHAKE-TRUST-4)  IO.bind(List<&1, String>, List<&2, String>, IO.args(),    xs => IO.pure(List<&2, String>, words(xs)))# a name and its value in front of the pairs, when `IO.get_env` found onedef kept(  +name: String,  got: Result<&1, &1, U32 & String, String>,  rest: List<&2, C.Var>) -> List<&2, C.Var>:  match got:    case Done{vv}:      (name, vv) <> rest    case Fail{_e}:      rest# the names that are set, each with its value, in orderdef vars(names: List<&2, String>) -> IO(List<&2, C.Var>):  # noqa: L001 IO: reads env vars (SHAKE-TRUST-5)  match names:    case Nil{}:      IO.pure(List<&2, C.Var>, [])    case Con{+hh, tt}:      IO.bind(Result<&1, &1, U32 & String, String>, List<&2, C.Var>, IO.get_env(hh),        got => IO.bind(List<&2, C.Var>, List<&2, C.Var>, vars(tt),          rest => IO.pure(List<&2, C.Var>, kept(hh, got, rest))))# the env vars a spec names that are set, each with its valuedef env_vars(spec: C.Cli) -> IO(List<&2, C.Var>):  # noqa: L001 IO: reads env vars (SHAKE-TRUST-5)  vars(C.env.names(spec))