Add `sample` function to List module, add `log` and `exp` functions to Float module (#772)

2 files changed, 127 insertions, 0 deletions

diff --git a/test/gleam/float_test.gleam b/test/gleam/float_test.gleam
index 7124d80..1c8f96b 100644
--- a/test/gleam/float_test.gleam
+++ b/test/gleam/float_test.gleam
@@ -528,3 +528,81 @@ pub fn subtract_test() {
   |> float.subtract(2.0, _)
   |> should.equal(-1.0)
 }
+
+pub fn logarithm_test() {
+  float.logarithm(1.0)
+  |> result.unwrap(or: 1.0)
+  |> float.loosely_equals(with: 0.0, tolerating: 0.001)
+  |> should.be_true
+
+  float.logarithm(2.718281828459045)
+  |> result.unwrap(or: 0.0)
+  |> float.loosely_equals(with: 1.0, tolerating: 0.001)
+  |> should.be_true
+
+  float.logarithm(10.0)
+  |> result.unwrap(or: 0.0)
+  |> float.loosely_equals(with: 2.302585092994046, tolerating: 0.001)
+  |> should.be_true
+
+  float.logarithm(100.0)
+  |> result.unwrap(or: 0.0)
+  |> float.loosely_equals(with: 4.605170185988092, tolerating: 0.001)
+  |> should.be_true
+
+  float.logarithm(0.5)
+  |> result.unwrap(or: 0.0)
+  |> float.loosely_equals(with: -0.6931471805599453, tolerating: 0.001)
+  |> should.be_true
+
+  float.logarithm(0.1)
+  |> result.unwrap(or: 0.0)
+  |> float.loosely_equals(with: -2.3025850929940455, tolerating: 0.001)
+  |> should.be_true
+
+  float.logarithm(0.0)
+  |> should.equal(Error(Nil))
+
+  float.logarithm(-1.0)
+  |> should.equal(Error(Nil))
+
+  float.logarithm(-100.0)
+  |> should.equal(Error(Nil))
+
+  float.logarithm(-0.1)
+  |> should.equal(Error(Nil))
+}
+
+pub fn exponential_test() {
+  float.exponential(0.0)
+  |> float.loosely_equals(with: 1.0, tolerating: 0.001)
+  |> should.be_true
+
+  float.exponential(1.0)
+  |> float.loosely_equals(with: 2.718281828459045, tolerating: 0.001)
+  |> should.be_true
+
+  float.exponential(2.0)
+  |> float.loosely_equals(with: 7.38905609893065, tolerating: 0.001)
+  |> should.be_true
+
+  float.exponential(-1.0)
+  |> float.loosely_equals(with: 0.36787944117144233, tolerating: 0.001)
+  |> should.be_true
+
+  float.exponential(5.0)
+  |> float.loosely_equals(with: 148.4131591025766, tolerating: 0.001)
+  |> should.be_true
+
+  float.exponential(-5.0)
+  |> float.loosely_equals(with: 0.006737946999085467, tolerating: 0.001)
+  |> should.be_true
+
+  float.exponential(0.000001)
+  |> float.loosely_equals(with: 1.0000010000005, tolerating: 0.001)
+  |> should.be_true
+
+  float.exponential(-100.0)
+  |> float.loosely_equals(with: 3.720075976020836e-44, tolerating: 0.001)
+  |> should.be_true
+}
diff --git a/test/gleam/list_test.gleam b/test/gleam/list_test.gleam
index 2a67f94..6228396 100644
--- a/test/gleam/list_test.gleam
+++ b/test/gleam/list_test.gleam
@@ -1299,3 +1299,52 @@ pub fn max_test() {
   |> list.max(string.compare)
   |> should.equal(Ok("c"))
 }
+
+pub fn sample_test() {
+  []
+  |> list.sample(3)
+  |> should.equal([])
+
+  [1, 2, 3]
+  |> list.sample(0)
+  |> should.equal([])
+
+  [1, 2, 3]
+  |> list.sample(-1)
+  |> should.equal([])
+
+  [1, 2]
+  |> list.sample(5)
+  |> list.sort(int.compare)
+  |> should.equal([1, 2])
+
+  [1]
+  |> list.sample(1)
+  |> should.equal([1])
+
+  let input = list.range(1, 100)
+  let sample = list.sample(input, 10)
+  list.length(sample)
+  |> should.equal(10)
+
+  let repeated = [1, 1, 1, 1, 1]
+  let sample = list.sample(repeated, 3)
+  sample
+  |> list.all(fn(x) { x == 1 })
+  |> should.be_true()
+
+  let input = list.range(1, 1000)
+  let sample = list.sample(input, 100)
+  sample
+  |> list.sort(int.compare)
+  |> list.all(fn(x) { x >= 1 && x <= 1000 })
+  |> should.be_true()
+
+  list.length(sample)
+  |> should.equal(100)
+
+  let min = list.fold(sample, 1000, int.min)
+  let max = list.fold(sample, 1, int.max)
+  should.be_true(min >= 1)
+  should.be_true(max <= 1000)
+}
\ No newline at end of file