Add set.is_empty

2 files changed, 35 insertions, 0 deletions

diff --git a/src/gleam/set.gleam b/src/gleam/set.gleam
index d0b4f16..12bfba1 100644
--- a/src/gleam/set.gleam
+++ b/src/gleam/set.gleam
@@ -51,6 +51,24 @@ pub fn size(set: Set(member)) -> Int {
   dict.size(set.dict)
 }
 
+/// Determines whether or not the set is empty.
+///
+/// ## Examples
+///
+/// ```gleam
+/// new() |> is_empty
+/// // -> True
+/// ```
+///
+/// ```gleam
+/// new() |> insert(1) |> is_empty
+/// // -> False
+/// ```
+///
+pub fn is_empty(set: Set(member)) -> Bool {
+  set == new()
+}
+
 /// Inserts an member into the set.
 ///
 /// This function runs in logarithmic time.
diff --git a/test/gleam/set_test.gleam b/test/gleam/set_test.gleam
index 94dd5da..908fe29 100644
--- a/test/gleam/set_test.gleam
+++ b/test/gleam/set_test.gleam
@@ -22,6 +22,23 @@ pub fn size_test() {
   |> should.equal(2)
 }
 
+pub fn is_empty_test() {
+  set.new()
+  |> set.is_empty()
+  |> should.be_true()
+
+  set.new()
+  |> set.insert(1)
+  |> set.is_empty()
+  |> should.be_false()
+
+  set.new()
+  |> set.insert(1)
+  |> set.delete(1)
+  |> set.is_empty()
+  |> should.be_true()
+}
+
 pub fn contains_test() {
   set.new()
   |> set.insert(1)