process.pid_from_dynamic

Closes #41

Author: lpil

.github/workflows/test.yml

@@ -14,8 +14,8 @@ jobs:
       - uses: actions/checkout@v3
       - uses: erlef/setup-beam@v1
         with:
-          otp-version: "25.2"
+          otp-version: "26.2"
           rebar3-version: "3"
-          gleam-version: "0.32"
+          gleam-version: "1.0.0"
       - run: gleam test
       - run: gleam format --check src test

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.25.0 - 2024-03-20
+
+- Updated for `gleam_stdlib` v0.33.0.
+
 ## v0.24.0 - 2024-01-03
 
 - Updated for `gleam_stdlib` v0.33.0.

gleam.toml

@@ -1,6 +1,6 @@
 name = "gleam_erlang"
 
-version = "0.24.0"
+version = "0.25.0"
 licences = ["Apache-2.0"]
 description = "A Gleam library for working with Erlang"
 

src/gleam/erlang.gleam

@@ -1,7 +1,7 @@
 import gleam/dynamic.{type Dynamic}
-import gleam/list
 import gleam/erlang/atom.{type Atom}
 import gleam/erlang/charlist.{type Charlist}
+import gleam/list
 
 @external(erlang, "io_lib", "format")
 fn erl_format(a: String, b: List(a)) -> Charlist

src/gleam/erlang/process.gleam

@@ -1,7 +1,7 @@
-import gleam/string
-import gleam/dynamic.{type Dynamic}
+import gleam/dynamic.{type DecodeErrors, type Dynamic}
 import gleam/erlang.{type Reference}
 import gleam/erlang/atom.{type Atom}
+import gleam/string
 
 /// A `Pid` (or Process identifier) is a reference to an Erlang process. Each
 /// process has a `Pid` and it is one of the lowest level building blocks of
@@ -563,10 +563,9 @@ pub fn try_call(
   let result =
     new_selector()
     |> selecting(reply_subject, Ok)
-    |> selecting_process_down(
-      monitor,
-      fn(down: ProcessDown) { Error(CalleeDown(reason: down.reason)) },
-    )
+    |> selecting_process_down(monitor, fn(down: ProcessDown) {
+      Error(CalleeDown(reason: down.reason))
+    })
     |> select(timeout)
 
   // Demonitor the process and close the channels as we're done
@@ -744,3 +743,18 @@ pub fn unregister(name: Atom) -> Result(Nil, Nil)
 ///
 @external(erlang, "gleam_erlang_ffi", "process_named")
 pub fn named(name: Atom) -> Result(Pid, Nil)
+
+/// Checks to see whether a `Dynamic` value is a pid, and return the pid if
+/// it is.
+///
+/// ## Examples
+///
+///    > import gleam/dynamic
+///    > from_dynamic(dynamic.from(process.self()))
+///    Ok(process.self())
+///
+///    > from_dynamic(dynamic.from(123))
+///    Error([DecodeError(expected: "Pid", found: "Int", path: [])])
+///
+@external(erlang, "gleam_erlang_ffi", "pid_from_dynamic")
+pub fn pid_from_dynamic(from from: Dynamic) -> Result(Pid, DecodeErrors)

src/gleam_erlang_ffi.erl

@@ -6,7 +6,7 @@
     new_selector/0, link/1, insert_selector_handler/3, select/1, select/2,
     trap_exits/1, map_selector/2, merge_selector/2, flush_messages/0,
     priv_directory/1, connect_node/1, register_process/2, unregister_process/1,
-    process_named/1, identity/1
+    process_named/1, identity/1, pid_from_dynamic/1
 ]).
 
 -spec atom_from_string(binary()) -> {ok, atom()} | {error, atom_not_loaded}.
@@ -20,6 +20,11 @@ atom_from_dynamic(Data) when is_atom(Data) ->
 atom_from_dynamic(Data) ->
     {error, [{decode_error, <<"Atom">>, gleam@dynamic:classify(Data), []}]}.
 
+pid_from_dynamic(Data) when is_pid(Data) ->
+    {ok, Data};
+pid_from_dynamic(Data) ->
+    {error, [{decode_error, <<"Pid">>, gleam@dynamic:classify(Data), []}]}.
+
 -spec get_line(io:prompt()) -> {ok, unicode:unicode_binary()} | {error, eof | no_data}.
 get_line(Prompt) ->
     case io:get_line(Prompt) of

test/gleam/erlang/atom_test.gleam

@@ -1,5 +1,5 @@
-import gleam/erlang/atom
 import gleam/dynamic.{DecodeError}
+import gleam/erlang/atom
 
 pub fn from_string_test() {
   let assert Ok(_) = atom.from_string("ok")

test/gleam/erlang/env_test.gleam

@@ -1,5 +1,5 @@
-import gleam/erlang/os
 import gleam/dict
+import gleam/erlang/os
 
 pub fn get_all_test() {
   os.set_env("MYVAR", "MYVALUE")

test/gleam/erlang/node_tests.gleam

@@ -1,5 +1,5 @@
-import gleam/erlang/node
 import gleam/erlang/atom
+import gleam/erlang/node
 
 // TODO: Improve these tests by spawning a peer node.