From 0b70df9a3f1122113a856b0ad749b51862e415ca Mon Sep 17 00:00:00 2001 From: Robert Attard Date: Fri, 30 Jul 2021 14:12:14 -0400 Subject: iterator.try_fold --- test/gleam/iterator_test.gleam | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'test') diff --git a/test/gleam/iterator_test.gleam b/test/gleam/iterator_test.gleam index 8de4251..84292e4 100644 --- a/test/gleam/iterator_test.gleam +++ b/test/gleam/iterator_test.gleam @@ -430,7 +430,7 @@ pub fn interleave_test() { |> should.equal([1, 100, 2, 3, 4]) } -// a |> from_list |> fold_until(a, f) == a |> list.fold_until(_, a, f) +// a |> from_list |> fold_until(acc, f) == a |> list.fold_until(acc, f) pub fn fold_until_test() { let test = fn(subject, acc, f) { subject @@ -455,3 +455,34 @@ pub fn fold_until_test() { |> iterator.fold_until([], f) |> should.equal([5, 4, 3, 2, 1]) } + +// a |> from_list |> try_fold(acc, f) == a |> list.try_fold(acc, f) +pub fn try_fold_test() { + let test = fn(subject, acc, fun) { + subject + |> iterator.from_list() + |> iterator.try_fold(acc, fun) + |> should.equal(list.try_fold(subject, acc, fun)) + } + + let f = fn(e, acc) { + case e % 2 { + 0 -> Ok(e + acc) + _ -> Error("tried to add an odd number") + } + } + test([], 0, f) + test([2, 4, 6], 0, f) + test([1, 2, 3], 0, f) + test([1, 2, 3, 4, 5, 6, 7, 8], 0, f) + + [0, 2, 4, 6] + |> iterator.from_list() + |> iterator.try_fold(0, f) + |> should.equal(Ok(12)) + + [1, 2, 3, 4] + |> iterator.from_list() + |> iterator.try_fold(0, f) + |> should.equal(Error("tried to add an odd number")) +} -- cgit v1.2.3