v0.30.0

Author: lpil

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.30.0 - 2024-11-11
+
+- The `gleam/erlang/process` module gains the `deselecting` function.
+
 ## v0.29.0 - 2024-11-10
 
 - The `gleam/erlang/process` module gains the `call_forever` and

gleam.toml

@@ -1,6 +1,6 @@
 name = "gleam_erlang"
 
-version = "0.29.0"
+version = "0.30.0"
 licences = ["Apache-2.0"]
 description = "A Gleam library for working with Erlang"
 

src/gleam/erlang/process.gleam

@@ -256,14 +256,17 @@ pub fn selecting_trapped_exits(
 @external(erlang, "gleam_erlang_ffi", "flush_messages")
 pub fn flush_messages() -> Nil
 
-/// Add a new `Subject` to the `Selector` to that it's messages can be received.
+/// Add a new `Subject` to the `Selector` so that its messages can be selected
+/// from the receiver process inbox.
 ///
 /// The `mapping` function provided with the `Subject` can be used to convert
 /// the type of messages received using this `Subject`. This is useful for when
 /// you wish to add multiple `Subject`s to a `Selector` when they have differing
 /// message types. If you do not wish to transform the incoming messages in any
 /// way then the `identity` function can be given.
 ///
+/// See `deselecting` to remove a subject from a selector.
+///
 pub fn selecting(
   selector: Selector(payload),
   for subject: Subject(message),
@@ -273,6 +276,16 @@ pub fn selecting(
   insert_selector_handler(selector, #(subject.tag, 2), handler)
 }
 
+/// Remove a new `Subject` from the `Selector` so that its messages will not be
+/// selected from the receiver process inbox.
+///
+pub fn deselecting(
+  selector: Selector(payload),
+  for subject: Subject(message),
+) -> Selector(payload) {
+  remove_selector_handler(selector, #(subject.tag, 2))
+}
+
 /// Add a handler to a selector for 2 element tuple messages with a given tag
 /// element in the first position.
 ///

test/gleam/erlang/process_test.gleam

@@ -5,6 +5,7 @@ import gleam/float
 import gleam/function
 import gleam/int
 import gleam/option.{Some}
+import gleeunit/should
 
 pub fn self_test() {
   let subject = process.new_subject()
@@ -613,3 +614,24 @@ pub fn pid_from_dynamic_test() {
     |> dynamic.from
     |> process.pid_from_dynamic
 }
+
+pub fn deselecting_test() {
+  let subject1 = process.new_subject()
+  let subject2 = process.new_subject()
+  let selector0 = process.new_selector()
+  let selector1 = selector0 |> process.selecting(subject1, function.identity)
+  let selector2 = selector1 |> process.selecting(subject2, function.identity)
+
+  selector2
+  |> process.deselecting(subject2)
+  |> should.equal(selector1)
+
+  selector1
+  |> process.deselecting(subject1)
+  |> should.equal(selector0)
+
+  selector2
+  |> process.deselecting(subject1)
+  |> process.deselecting(subject2)
+  |> should.equal(selector0)
+}