Add square_root function for floats

2 files changed, 31 insertions, 0 deletions

diff --git a/src/gleam/float.gleam b/src/gleam/float.gleam
index 3767113..448424a 100644
--- a/src/gleam/float.gleam
+++ b/src/gleam/float.gleam
@@ -142,3 +142,20 @@ pub external fn absolute_value(Float) -> Float =
 ///
 pub external fn power(base: Float, exponent: Float) -> Float =
   "math" "pow"
+
+/// Returns the square root of the input as a float.
+///
+/// ## Examples
+///
+///    > square_root(4.0)
+///    2.0
+///
+///    > square_root(-16.0)
+///    Error(Nil)
+///
+pub fn square_root(number: Float) -> Result(Float, Nil) {
+  case number <. 0.0 {
+    True -> Error(Nil)
+    False -> Ok(power(number, 0.5))
+  }
+}
diff --git a/test/gleam/float_test.gleam b/test/gleam/float_test.gleam
index 234df59..79bece2 100644
--- a/test/gleam/float_test.gleam
+++ b/test/gleam/float_test.gleam
@@ -217,3 +217,17 @@ pub fn power_test() {
   float.power(2.0, -1.0)
   |> should.equal(0.5)
 }
+
+pub fn square_root_test() {
+  float.square_root(4.0)
+  |> should.equal(Ok(2.0))
+
+  float.square_root(16.0)
+  |> should.equal(Ok(4.0))
+
+  float.square_root(0.0)
+  |> should.equal(Ok(0.0))
+
+  float.square_root(-4.0)
+  |> should.equal(Error(Nil))
+}