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| author | Alice Dee <alice.dee@guardian.co.uk> | 2019-05-11 17:16:06 +0100 |
|---|---|---|
| committer | Louis Pilfold <louis@lpil.uk> | 2019-05-11 17:22:56 +0100 |
| commit | f7d6fe3105fbf650f0f0f95568aca801048f6d15 (patch) | |
| tree | ed60af8c3017a5c6b820a8f7f500eff8360f1d56 /gen | |
| parent | 1d91cb03285269794823843e54ae3dbb43e7c4d6 (diff) | |
| download | gleam_stdlib-f7d6fe3105fbf650f0f0f95568aca801048f6d15.tar.gz gleam_stdlib-f7d6fe3105fbf650f0f0f95568aca801048f6d15.zip | |
Adds split to list stdlib
Diffstat (limited to 'gen')
| -rw-r--r-- | gen/src/list.erl | 20 | ||||
| -rw-r--r-- | gen/test/list_test.erl | 10 |
2 files changed, 28 insertions, 2 deletions
diff --git a/gen/src/list.erl b/gen/src/list.erl index 96dd7d2..1395112 100644 --- a/gen/src/list.erl +++ b/gen/src/list.erl @@ -1,7 +1,7 @@ -module(list). -compile(no_auto_import). --export([length/1, reverse/1, is_empty/1, contains/2, head/1, tail/1, filter/2, map/2, index_map/2, traverse/2, drop/2, take/2, new/0, append/2, flatten/1, fold/3, fold_right/3, find/2, all/2, any/2, zip/2, strict_zip/2, intersperse/2, at/2, unique/1, sort/1, range/2, repeat/2]). +-export([length/1, reverse/1, is_empty/1, contains/2, head/1, tail/1, filter/2, map/2, index_map/2, traverse/2, drop/2, take/2, new/0, append/2, flatten/1, fold/3, fold_right/3, find/2, all/2, any/2, zip/2, strict_zip/2, intersperse/2, at/2, unique/1, sort/1, range/2, repeat/2, split/2]). length(A) -> erlang:length(A). @@ -331,3 +331,21 @@ do_repeat(A, Times, Acc) -> repeat(A, Times) -> do_repeat(A, Times, []). + +do_split(List, N, Taken) -> + case N =< 0 of + true -> + {reverse(Taken), List}; + + false -> + case List of + [] -> + {reverse(Taken), []}; + + [X | Xs] -> + do_split(Xs, N - 1, [X | Taken]) + end + end. + +split(List, N) -> + do_split(List, N, []). diff --git a/gen/test/list_test.erl b/gen/test/list_test.erl index b00d507..705cb3c 100644 --- a/gen/test/list_test.erl +++ b/gen/test/list_test.erl @@ -1,7 +1,7 @@ -module(list_test). -compile(no_auto_import). --export([length_test/0, reverse_test/0, is_empty_test/0, contains_test/0, head_test/0, tail_test/0, filter_test/0, map_test/0, traverse_test/0, drop_test/0, take_test/0, new_test/0, append_test/0, flatten_test/0, fold_test/0, fold_right_test/0, find_test/0, all_test/0, any_test/0, zip_test/0, strict_zip_test/0, intersperse_test/0, at_test/0, unique_test/0, sort_test/0, index_map_test/0, range_test/0, repeat_test/0]). +-export([length_test/0, reverse_test/0, is_empty_test/0, contains_test/0, head_test/0, tail_test/0, filter_test/0, map_test/0, traverse_test/0, drop_test/0, take_test/0, new_test/0, append_test/0, flatten_test/0, fold_test/0, fold_right_test/0, find_test/0, all_test/0, any_test/0, zip_test/0, strict_zip_test/0, intersperse_test/0, at_test/0, unique_test/0, sort_test/0, index_map_test/0, range_test/0, repeat_test/0, split_test/0]). length_test() -> expect:equal(list:length([]), 0), @@ -162,3 +162,11 @@ repeat_test() -> expect:equal(list:repeat(2, 3), [2, 2, 2]), expect:equal(list:repeat(<<"x">>, 5), [<<"x">>, <<"x">>, <<"x">>, <<"x">>, <<"x">>]). + +split_test() -> + expect:equal(list:split([], 0), {[], []}), + expect:equal(list:split([0, 1, 2, 3, 4], 0), {[], [0, 1, 2, 3, 4]}), + expect:equal(list:split([0, 1, 2, 3, 4], -2), {[], [0, 1, 2, 3, 4]}), + expect:equal(list:split([0, 1, 2, 3, 4], 1), {[0], [1, 2, 3, 4]}), + expect:equal(list:split([0, 1, 2, 3, 4], 3), {[0, 1, 2], [3, 4]}), + expect:equal(list:split([0, 1, 2, 3, 4], 9), {[0, 1, 2, 3, 4], []}). |