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| author | Robert Peterson <robert.peterson@gmail.com> | 2019-04-18 07:41:38 -0700 |
|---|---|---|
| committer | Louis Pilfold <louis@lpil.uk> | 2019-04-18 16:16:05 +0100 |
| commit | 108d01c3efda55d63193f33e29fb878b07313dfc (patch) | |
| tree | 82750c1490569b6c986803697dd2b9f72d6e3c80 /gen | |
| parent | f2b09ca44f9448cf351093abdf50f9bb6e411423 (diff) | |
| download | gleam_stdlib-108d01c3efda55d63193f33e29fb878b07313dfc.tar.gz gleam_stdlib-108d01c3efda55d63193f33e29fb878b07313dfc.zip | |
Add list:index_map
Diffstat (limited to 'gen')
| -rw-r--r-- | gen/src/list.erl | 14 | ||||
| -rw-r--r-- | gen/test/list_test.erl | 9 |
2 files changed, 21 insertions, 2 deletions
diff --git a/gen/src/list.erl b/gen/src/list.erl index 10a093a..36fb42d 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, 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, intersperse/2, at/2, unique/1, sort/1]). +-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, intersperse/2, at/2, unique/1, sort/1]). length(A) -> erlang:length(A). @@ -70,6 +70,18 @@ do_map(List, Fun, Acc) -> map(List, Fun) -> do_map(List, Fun, []). +do_index_map(List, Fun, Index, Acc) -> + case List of + [] -> + reverse(Acc); + + [X | Xs] -> + do_index_map(Xs, Fun, Index + 1, [Fun(Index, X) | Acc]) + end. + +index_map(List, Fun) -> + do_index_map(List, Fun, 0, []). + do_traverse(List, Fun, Acc) -> case List of [] -> diff --git a/gen/test/list_test.erl b/gen/test/list_test.erl index 6105a88..1944d25 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, intersperse_test/0, at_test/0, unique_test/0, sort_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, intersperse_test/0, at_test/0, unique_test/0, sort_test/0, index_map_test/0]). length_test() -> expect:equal(list:length([]), 0), @@ -132,3 +132,10 @@ sort_test() -> expect:equal(list:sort([4, 3, 6, 5, 4]), [3, 4, 4, 5, 6]), expect:equal(list:sort([]), []), expect:equal(list:sort([{1, 2}, {4, 5}, {3, 2}]), [{1, 2}, {3, 2}, {4, 5}]). + +index_map_test() -> + expect:equal(list:index_map([3, 4, 5], fun(I, X) -> {I, X} end), + [{0, 3}, {1, 4}, {2, 5}]), + F = fun(I, X) -> str:append(X, str:from_int(I)) end, + expect:equal(list:index_map([<<"a">>, <<"b">>, <<"c">>], F), + [<<"a0">>, <<"b1">>, <<"c2">>]). |