2 files changed, 72 insertions, 0 deletions
diff --git a/src/gleam/float.gleam b/src/gleam/float.gleam
index 701b45e..9a922c1 100644
--- a/src/gleam/float.gleam
+++ b/src/gleam/float.gleam
@@ -428,6 +428,55 @@ fn do_product(numbers: List(Float), initial: Float) -> Float {
 @external(javascript, "../gleam_stdlib.mjs", "random_uniform")
 pub fn random() -> Float
 
+/// Computes the modulo of an float division of inputs as a `Result`.
+///
+/// Returns division of the inputs as a `Result`: If the given divisor equals
+/// `0`, this function returns an `Error`.
+///
+/// ## Examples
+///
+/// ```gleam
+/// modulo(3.0, 2.0)
+/// // -> Ok(1.0)
+/// ```
+///
+/// ```gleam
+/// modulo(1.0, 0.0)
+/// // -> Error(Nil)
+/// ```
+///
+/// ```gleam
+/// modulo(10.0, -1.0)
+/// // -> Ok(0.0)
+/// ```
+///
+/// ```gleam
+/// modulo(13.0, by: 3.0)
+/// // -> Ok(1.0)
+/// ```
+///
+/// ```gleam
+/// modulo(-13.0, by: 3.0)
+/// // -> Ok(2.0)
+/// ```
+///
+/// ```gleam
+/// modulo(13.0, by: -3.0)
+/// // -> Ok(-2.0)
+/// ```
+///
+/// ```gleam
+/// modulo(-13.0, by: -3.0)
+/// // -> Ok(-1.0)
+/// ```
+///
+pub fn modulo(dividend: Float, by divisor: Float) -> Result(Float, Nil) {
+  case divisor {
+    0.0 -> Error(Nil)
+    _ -> Ok(dividend -. floor(dividend /. divisor) *. divisor)
+  }
+}
+
 /// Returns division of the inputs as a `Result`.
 ///
 /// ## Examples
diff --git a/test/gleam/float_test.gleam b/test/gleam/float_test.gleam
index 6731c23..11a8e25 100644
--- a/test/gleam/float_test.gleam
+++ b/test/gleam/float_test.gleam
@@ -384,6 +384,29 @@ pub fn random_test() {
   |> should.be_true
 }
 
+pub fn modulo_test() {
+  float.modulo(3.0, 2.0)
+  |> should.equal(Ok(1.0))
+
+  float.modulo(1.0, 0.0)
+  |> should.equal(Error(Nil))
+
+  float.modulo(10.0, -1.0)
+  |> should.equal(Ok(0.0))
+
+  float.modulo(13.0, by: 3.0)
+  |> should.equal(Ok(1.0))
+
+  float.modulo(-13.0, by: 3.0)
+  |> should.equal(Ok(2.0))
+
+  float.modulo(13.0, by: -3.0)
+  |> should.equal(Ok(-2.0))
+
+  float.modulo(-13.0, by: -3.0)
+  |> should.equal(Ok(-1.0))
+}
+
 pub fn divide_test() {
   float.divide(1.0, 1.0)
   |> should.equal(Ok(1.0))