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src/gleam@list.erl

-module(gleam@list).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/gleam/list.gleam").
-export([length/1, count/2, reverse/1, is_empty/1, contains/2, first/1, rest/1, group/2, filter/2, filter_map/2, map/2, map2/3, map_fold/3, index_map/2, try_map/2, drop/2, take/2, new/0, wrap/1, append/2, prepend/2, flatten/1, flat_map/2, fold/3, fold_right/3, index_fold/3, try_fold/3, fold_until/3, find/2, find_map/2, all/2, any/2, zip/2, strict_zip/2, unzip/1, intersperse/2, unique/1, sort/2, range/2, repeat/2, split/2, split_while/2, key_find/2, key_filter/2, key_pop/2, key_set/3, each/2, try_each/2, partition/2, window/2, window_by_2/1, drop_while/2, take_while/2, chunk/2, sized_chunk/2, reduce/2, scan/3, last/1, combinations/2, combination_pairs/1, transpose/1, interleave/1, shuffle/1, max/2, sample/2, permutations/1]).
-export_type([continue_or_stop/1, sorting/0]).
-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.
?MODULEDOC(
" Lists are an ordered sequence of elements and are one of the most common\n"
" data types in Gleam.\n"
"\n"
" New elements can be added and removed from the front of a list in\n"
" constant time, while adding and removing from the end requires traversing\n"
" and copying the whole list, so keep this in mind when designing your\n"
" programs.\n"
"\n"
" There is a dedicated syntax for prefixing to a list:\n"
"\n"
" ```gleam\n"
" let new_list = [1, 2, ..existing_list]\n"
" ```\n"
"\n"
" And a matching syntax for getting the first elements of a list:\n"
"\n"
" ```gleam\n"
" case list {\n"
" [first_element, ..rest] -> first_element\n"
" _ -> \"this pattern matches when the list is empty\"\n"
" }\n"
" ```\n"
"\n"
).
-type continue_or_stop(XI) :: {continue, XI} | {stop, XI}.
-type sorting() :: ascending | descending.
-file("src/gleam/list.gleam", 60).
-spec length_loop(list(any()), integer()) -> integer().
length_loop(List, Count) ->
case List of
[_ | List@1] ->
length_loop(List@1, Count + 1);
[] ->
Count
end.
-file("src/gleam/list.gleam", 56).
?DOC(
" Counts the number of elements in a given list.\n"
"\n"
" This function has to traverse the list to determine the number of elements,\n"
" so it runs in linear time.\n"
"\n"
" This function is natively implemented by the virtual machine and is highly\n"
" optimised.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" length([])\n"
" // -> 0\n"
" ```\n"
"\n"
" ```gleam\n"
" length([1])\n"
" // -> 1\n"
" ```\n"
"\n"
" ```gleam\n"
" length([1, 2])\n"
" // -> 2\n"
" ```\n"
).
-spec length(list(any())) -> integer().
length(List) ->
erlang:length(List).
-file("src/gleam/list.gleam", 93).
-spec count_loop(list(XP), fun((XP) -> boolean()), integer()) -> integer().
count_loop(List, Predicate, Acc) ->
case List of
[] ->
Acc;
[First | Rest] ->
case Predicate(First) of
true ->
count_loop(Rest, Predicate, Acc + 1);
false ->
count_loop(Rest, Predicate, Acc)
end
end.
-file("src/gleam/list.gleam", 89).
?DOC(
" Counts the number of elements in a given list satisfying a given predicate.\n"
"\n"
" This function has to traverse the list to determine the number of elements,\n"
" so it runs in linear time.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" count([], fn(a) { a > 0 })\n"
" // -> 0\n"
" ```\n"
"\n"
" ```gleam\n"
" count([1], fn(a) { a > 0 })\n"
" // -> 1\n"
" ```\n"
"\n"
" ```gleam\n"
" count([1, 2, 3], int.is_odd)\n"
" // -> 2\n"
" ```\n"
).
-spec count(list(XN), fun((XN) -> boolean())) -> integer().
count(List, Predicate) ->
count_loop(List, Predicate, 0).
-file("src/gleam/list.gleam", 131).
?DOC(
" Creates a new list from a given list containing the same elements but in the\n"
" opposite order.\n"
"\n"
" This function has to traverse the list to create the new reversed list, so\n"
" it runs in linear time.\n"
"\n"
" This function is natively implemented by the virtual machine and is highly\n"
" optimised.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" reverse([])\n"
" // -> []\n"
" ```\n"
"\n"
" ```gleam\n"
" reverse([1])\n"
" // -> [1]\n"
" ```\n"
"\n"
" ```gleam\n"
" reverse([1, 2])\n"
" // -> [2, 1]\n"
" ```\n"
).
-spec reverse(list(XR)) -> list(XR).
reverse(List) ->
lists:reverse(List).
-file("src/gleam/list.gleam", 168).
?DOC(
" Determines whether or not the list is empty.\n"
"\n"
" This function runs in constant time.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" is_empty([])\n"
" // -> True\n"
" ```\n"
"\n"
" ```gleam\n"
" is_empty([1])\n"
" // -> False\n"
" ```\n"
"\n"
" ```gleam\n"
" is_empty([1, 1])\n"
" // -> False\n"
" ```\n"
).
-spec is_empty(list(any())) -> boolean().
is_empty(List) ->
List =:= [].
-file("src/gleam/list.gleam", 204).
?DOC(
" Determines whether or not a given element exists within a given list.\n"
"\n"
" This function traverses the list to find the element, so it runs in linear\n"
" time.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" [] |> contains(any: 0)\n"
" // -> False\n"
" ```\n"
"\n"
" ```gleam\n"
" [0] |> contains(any: 0)\n"
" // -> True\n"
" ```\n"
"\n"
" ```gleam\n"
" [1] |> contains(any: 0)\n"
" // -> False\n"
" ```\n"
"\n"
" ```gleam\n"
" [1, 1] |> contains(any: 0)\n"
" // -> False\n"
" ```\n"
"\n"
" ```gleam\n"
" [1, 0] |> contains(any: 0)\n"
" // -> True\n"
" ```\n"
).
-spec contains(list(YA), YA) -> boolean().
contains(List, Elem) ->
case List of
[] ->
false;
[First | _] when First =:= Elem ->
true;
[_ | Rest] ->
contains(Rest, Elem)
end.
-file("src/gleam/list.gleam", 231).
?DOC(
" Gets the first element from the start of the list, if there is one.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" first([])\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" first([0])\n"
" // -> Ok(0)\n"
" ```\n"
"\n"
" ```gleam\n"
" first([1, 2])\n"
" // -> Ok(1)\n"
" ```\n"
).
-spec first(list(YC)) -> {ok, YC} | {error, nil}.
first(List) ->
case List of
[] ->
{error, nil};
[First | _] ->
{ok, First}
end.
-file("src/gleam/list.gleam", 260).
?DOC(
" Returns the list minus the first element. If the list is empty, `Error(Nil)` is\n"
" returned.\n"
"\n"
" This function runs in constant time and does not make a copy of the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" rest([])\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" rest([0])\n"
" // -> Ok([])\n"
" ```\n"
"\n"
" ```gleam\n"
" rest([1, 2])\n"
" // -> Ok([2])\n"
" ```\n"
).
-spec rest(list(YG)) -> {ok, list(YG)} | {error, nil}.
rest(List) ->
case List of
[] ->
{error, nil};
[_ | Rest] ->
{ok, Rest}
end.
-file("src/gleam/list.gleam", 302).
-spec group_loop(list(YR), fun((YR) -> YT), gleam@dict:dict(YT, list(YR))) -> gleam@dict:dict(YT, list(YR)).
group_loop(List, To_key, Groups) ->
case List of
[] ->
Groups;
[First | Rest] ->
Key = To_key(First),
Groups@1 = case gleam_stdlib:map_get(Groups, Key) of
{error, _} ->
gleam@dict:insert(Groups, Key, [First]);
{ok, Existing} ->
gleam@dict:insert(Groups, Key, [First | Existing])
end,
group_loop(Rest, To_key, Groups@1)
end.
-file("src/gleam/list.gleam", 298).
?DOC(
" Groups the elements from the given list by the given key function.\n"
"\n"
" Does not preserve the initial value order.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" import gleam/dict\n"
"\n"
" [Ok(3), Error(\"Wrong\"), Ok(200), Ok(73)]\n"
" |> group(by: fn(i) {\n"
" case i {\n"
" Ok(_) -> \"Successful\"\n"
" Error(_) -> \"Failed\"\n"
" }\n"
" })\n"
" |> dict.to_list\n"
" // -> [\n"
" // #(\"Failed\", [Error(\"Wrong\")]),\n"
" // #(\"Successful\", [Ok(73), Ok(200), Ok(3)])\n"
" // ]\n"
" ```\n"
"\n"
" ```gleam\n"
" import gleam/dict\n"
"\n"
" group([1,2,3,4,5], by: fn(i) { i - i / 3 * 3 })\n"
" |> dict.to_list\n"
" // -> [#(0, [3]), #(1, [4, 1]), #(2, [5, 2])]\n"
" ```\n"
).
-spec group(list(YL), fun((YL) -> YN)) -> gleam@dict:dict(YN, list(YL)).
group(List, Key) ->
group_loop(List, Key, maps:new()).
-file("src/gleam/list.gleam", 339).
-spec filter_loop(list(AAD), fun((AAD) -> boolean()), list(AAD)) -> list(AAD).
filter_loop(List, Fun, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
New_acc = case Fun(First) of
true ->
[First | Acc];
false ->
Acc
end,
filter_loop(Rest, Fun, New_acc)
end.
-file("src/gleam/list.gleam", 335).
?DOC(
" Returns a new list containing only the elements from the first list for\n"
" which the given functions returns `True`.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" filter([2, 4, 6, 1], fn(x) { x > 2 })\n"
" // -> [4, 6]\n"
" ```\n"
"\n"
" ```gleam\n"
" filter([2, 4, 6, 1], fn(x) { x > 6 })\n"
" // -> []\n"
" ```\n"
).
-spec filter(list(AAA), fun((AAA) -> boolean())) -> list(AAA).
filter(List, Predicate) ->
filter_loop(List, Predicate, []).
-file("src/gleam/list.gleam", 371).
-spec filter_map_loop(
list(AAO),
fun((AAO) -> {ok, AAQ} | {error, any()}),
list(AAQ)
) -> list(AAQ).
filter_map_loop(List, Fun, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
New_acc = case Fun(First) of
{ok, First@1} ->
[First@1 | Acc];
{error, _} ->
Acc
end,
filter_map_loop(Rest, Fun, New_acc)
end.
-file("src/gleam/list.gleam", 367).
?DOC(
" Returns a new list containing only the elements from the first list for\n"
" which the given functions returns `Ok(_)`.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" filter_map([2, 4, 6, 1], Error)\n"
" // -> []\n"
" ```\n"
"\n"
" ```gleam\n"
" filter_map([2, 4, 6, 1], fn(x) { Ok(x + 1) })\n"
" // -> [3, 5, 7, 2]\n"
" ```\n"
).
-spec filter_map(list(AAH), fun((AAH) -> {ok, AAJ} | {error, any()})) -> list(AAJ).
filter_map(List, Fun) ->
filter_map_loop(List, Fun, []).
-file("src/gleam/list.gleam", 401).
-spec map_loop(list(ABA), fun((ABA) -> ABC), list(ABC)) -> list(ABC).
map_loop(List, Fun, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
map_loop(Rest, Fun, [Fun(First) | Acc])
end.
-file("src/gleam/list.gleam", 397).
?DOC(
" Returns a new list containing the results of applying the supplied function to each element.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" map([2, 4, 6], fn(x) { x * 2 })\n"
" // -> [4, 8, 12]\n"
" ```\n"
).
-spec map(list(AAW), fun((AAW) -> AAY)) -> list(AAY).
map(List, Fun) ->
map_loop(List, Fun, []).
-file("src/gleam/list.gleam", 428).
-spec map2_loop(list(ABL), list(ABN), fun((ABL, ABN) -> ABP), list(ABP)) -> list(ABP).
map2_loop(List1, List2, Fun, Acc) ->
case {List1, List2} of
{[], _} ->
lists:reverse(Acc);
{_, []} ->
lists:reverse(Acc);
{[A | As_], [B | Bs]} ->
map2_loop(As_, Bs, Fun, [Fun(A, B) | Acc])
end.
-file("src/gleam/list.gleam", 424).
?DOC(
" Combines two lists into a single list using the given function.\n"
"\n"
" If a list is longer than the other the extra elements are dropped.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" map2([1, 2, 3], [4, 5, 6], fn(x, y) { x + y })\n"
" // -> [5, 7, 9]\n"
" ```\n"
"\n"
" ```gleam\n"
" map2([1, 2], [\"a\", \"b\", \"c\"], fn(i, x) { #(i, x) })\n"
" // -> [#(1, \"a\"), #(2, \"b\")]\n"
" ```\n"
).
-spec map2(list(ABF), list(ABH), fun((ABF, ABH) -> ABJ)) -> list(ABJ).
map2(List1, List2, Fun) ->
map2_loop(List1, List2, Fun, []).
-file("src/gleam/list.gleam", 461).
-spec map_fold_loop(list(ABX), fun((ABZ, ABX) -> {ABZ, ACA}), ABZ, list(ACA)) -> {ABZ,
list(ACA)}.
map_fold_loop(List, Fun, Acc, List_acc) ->
case List of
[] ->
{Acc, lists:reverse(List_acc)};
[First | Rest] ->
{Acc@1, First@1} = Fun(Acc, First),
map_fold_loop(Rest, Fun, Acc@1, [First@1 | List_acc])
end.
-file("src/gleam/list.gleam", 453).
?DOC(
" Similar to `map` but also lets you pass around an accumulated value.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" map_fold(\n"
" over: [1, 2, 3],\n"
" from: 100,\n"
" with: fn(memo, i) { #(memo + i, i * 2) }\n"
" )\n"
" // -> #(106, [2, 4, 6])\n"
" ```\n"
).
-spec map_fold(list(ABS), ABU, fun((ABU, ABS) -> {ABU, ABV})) -> {ABU,
list(ABV)}.
map_fold(List, Initial, Fun) ->
map_fold_loop(List, Fun, Initial, []).
-file("src/gleam/list.gleam", 493).
-spec index_map_loop(
list(ACH),
fun((ACH, integer()) -> ACJ),
integer(),
list(ACJ)
) -> list(ACJ).
index_map_loop(List, Fun, Index, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
Acc@1 = [Fun(First, Index) | Acc],
index_map_loop(Rest, Fun, Index + 1, Acc@1)
end.
-file("src/gleam/list.gleam", 489).
?DOC(
" Similar to `map`, but the supplied function will also be passed the index\n"
" of the element being mapped as an additional argument.\n"
"\n"
" The index starts at 0, so the first element is 0, the second is 1, and so\n"
" on.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" index_map([\"a\", \"b\"], fn(x, i) { #(i, x) })\n"
" // -> [#(0, \"a\"), #(1, \"b\")]\n"
" ```\n"
).
-spec index_map(list(ACD), fun((ACD, integer()) -> ACF)) -> list(ACF).
index_map(List, Fun) ->
index_map_loop(List, Fun, 0, []).
-file("src/gleam/list.gleam", 547).
-spec try_map_loop(list(ACV), fun((ACV) -> {ok, ACX} | {error, ACY}), list(ACX)) -> {ok,
list(ACX)} |
{error, ACY}.
try_map_loop(List, Fun, Acc) ->
case List of
[] ->
{ok, lists:reverse(Acc)};
[First | Rest] ->
case Fun(First) of
{ok, First@1} ->
try_map_loop(Rest, Fun, [First@1 | Acc]);
{error, Error} ->
{error, Error}
end
end.
-file("src/gleam/list.gleam", 540).
?DOC(
" Takes a function that returns a `Result` and applies it to each element in a\n"
" given list in turn.\n"
"\n"
" If the function returns `Ok(new_value)` for all elements in the list then a\n"
" list of the new values is returned.\n"
"\n"
" If the function returns `Error(reason)` for any of the elements then it is\n"
" returned immediately. None of the elements in the list are processed after\n"
" one returns an `Error`.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" try_map([1, 2, 3], fn(x) { Ok(x + 2) })\n"
" // -> Ok([3, 4, 5])\n"
" ```\n"
"\n"
" ```gleam\n"
" try_map([1, 2, 3], fn(_) { Error(0) })\n"
" // -> Error(0)\n"
" ```\n"
"\n"
" ```gleam\n"
" try_map([[1], [2, 3]], first)\n"
" // -> Ok([1, 2])\n"
" ```\n"
"\n"
" ```gleam\n"
" try_map([[1], [], [2]], first)\n"
" // -> Error(Nil)\n"
" ```\n"
).
-spec try_map(list(ACM), fun((ACM) -> {ok, ACO} | {error, ACP})) -> {ok,
list(ACO)} |
{error, ACP}.
try_map(List, Fun) ->
try_map_loop(List, Fun, []).
-file("src/gleam/list.gleam", 582).
?DOC(
" Returns a list that is the given list with up to the given number of\n"
" elements removed from the front of the list.\n"
"\n"
" If the element has less than the number of elements an empty list is\n"
" returned.\n"
"\n"
" This function runs in linear time but does not copy the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" drop([1, 2, 3, 4], 2)\n"
" // -> [3, 4]\n"
" ```\n"
"\n"
" ```gleam\n"
" drop([1, 2, 3, 4], 9)\n"
" // -> []\n"
" ```\n"
).
-spec drop(list(ADF), integer()) -> list(ADF).
drop(List, N) ->
case N =< 0 of
true ->
List;
false ->
case List of
[] ->
[];
[_ | Rest] ->
drop(Rest, N - 1)
end
end.
-file("src/gleam/list.gleam", 617).
-spec take_loop(list(ADL), integer(), list(ADL)) -> list(ADL).
take_loop(List, N, Acc) ->
case N =< 0 of
true ->
lists:reverse(Acc);
false ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
take_loop(Rest, N - 1, [First | Acc])
end
end.
-file("src/gleam/list.gleam", 613).
?DOC(
" Returns a list containing the first given number of elements from the given\n"
" list.\n"
"\n"
" If the element has less than the number of elements then the full list is\n"
" returned.\n"
"\n"
" This function runs in linear time.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" take([1, 2, 3, 4], 2)\n"
" // -> [1, 2]\n"
" ```\n"
"\n"
" ```gleam\n"
" take([1, 2, 3, 4], 9)\n"
" // -> [1, 2, 3, 4]\n"
" ```\n"
).
-spec take(list(ADI), integer()) -> list(ADI).
take(List, N) ->
take_loop(List, N, []).
-file("src/gleam/list.gleam", 637).
?DOC(
" Returns a new empty list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" new()\n"
" // -> []\n"
" ```\n"
).
-spec new() -> list(any()).
new() ->
[].
-file("src/gleam/list.gleam", 657).
?DOC(
" Returns the given item wrapped in a list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" wrap(1)\n"
" // -> [1]\n"
"\n"
" wrap([\"a\", \"b\", \"c\"])\n"
" // -> [[\"a\", \"b\", \"c\"]]\n"
"\n"
" wrap([[]])\n"
" // -> [[[]]]\n"
" ```\n"
).
-spec wrap(ADR) -> list(ADR).
wrap(Item) ->
[Item].
-file("src/gleam/list.gleam", 678).
-spec append_loop(list(ADX), list(ADX)) -> list(ADX).
append_loop(First, Second) ->
case First of
[] ->
Second;
[First@1 | Rest] ->
append_loop(Rest, [First@1 | Second])
end.
-file("src/gleam/list.gleam", 674).
?DOC(
" Joins one list onto the end of another.\n"
"\n"
" This function runs in linear time, and it traverses and copies the first\n"
" list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" append([1, 2], [3])\n"
" // -> [1, 2, 3]\n"
" ```\n"
).
-spec append(list(ADT), list(ADT)) -> list(ADT).
append(First, Second) ->
lists:append(First, Second).
-file("src/gleam/list.gleam", 698).
?DOC(
" Prefixes an item to a list. This can also be done using the dedicated\n"
" syntax instead\n"
"\n"
" ```gleam\n"
" let existing_list = [2, 3, 4]\n"
"\n"
" [1, ..existing_list]\n"
" // -> [1, 2, 3, 4]\n"
"\n"
" prepend(to: existing_list, this: 1)\n"
" // -> [1, 2, 3, 4]\n"
" ```\n"
).
-spec prepend(list(AEB), AEB) -> list(AEB).
prepend(List, Item) ->
[Item | List].
-file("src/gleam/list.gleam", 719).
-spec flatten_loop(list(list(AEI)), list(AEI)) -> list(AEI).
flatten_loop(Lists, Acc) ->
case Lists of
[] ->
lists:reverse(Acc);
[List | Further_lists] ->
flatten_loop(Further_lists, lists:reverse(List, Acc))
end.
-file("src/gleam/list.gleam", 715).
?DOC(
" Joins a list of lists into a single list.\n"
"\n"
" This function traverses all elements twice on the JavaScript target.\n"
" This function traverses all elements once on the Erlang target.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" flatten([[1], [2, 3], []])\n"
" // -> [1, 2, 3]\n"
" ```\n"
).
-spec flatten(list(list(AEE))) -> list(AEE).
flatten(Lists) ->
lists:append(Lists).
-file("src/gleam/list.gleam", 736).
?DOC(
" Maps the list with the given function into a list of lists, and then flattens it.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" flat_map([2, 4, 6], fn(x) { [x, x + 1] })\n"
" // -> [2, 3, 4, 5, 6, 7]\n"
" ```\n"
).
-spec flat_map(list(AEN), fun((AEN) -> list(AEP))) -> list(AEP).
flat_map(List, Fun) ->
lists:append(map(List, Fun)).
-file("src/gleam/list.gleam", 748).
?DOC(
" Reduces a list of elements into a single value by calling a given function\n"
" on each element, going from left to right.\n"
"\n"
" `fold([1, 2, 3], 0, add)` is the equivalent of\n"
" `add(add(add(0, 1), 2), 3)`.\n"
"\n"
" This function runs in linear time.\n"
).
-spec fold(list(AES), AEU, fun((AEU, AES) -> AEU)) -> AEU.
fold(List, Initial, Fun) ->
case List of
[] ->
Initial;
[First | Rest] ->
fold(Rest, Fun(Initial, First), Fun)
end.
-file("src/gleam/list.gleam", 770).
?DOC(
" Reduces a list of elements into a single value by calling a given function\n"
" on each element, going from right to left.\n"
"\n"
" `fold_right([1, 2, 3], 0, add)` is the equivalent of\n"
" `add(add(add(0, 3), 2), 1)`.\n"
"\n"
" This function runs in linear time.\n"
"\n"
" Unlike `fold` this function is not tail recursive. Where possible use\n"
" `fold` instead as it will use less memory.\n"
).
-spec fold_right(list(AEV), AEX, fun((AEX, AEV) -> AEX)) -> AEX.
fold_right(List, Initial, Fun) ->
case List of
[] ->
Initial;
[First | Rest] ->
Fun(fold_right(Rest, Initial, Fun), First)
end.
-file("src/gleam/list.gleam", 807).
-spec index_fold_loop(
list(AFB),
AFD,
fun((AFD, AFB, integer()) -> AFD),
integer()
) -> AFD.
index_fold_loop(Over, Acc, With, Index) ->
case Over of
[] ->
Acc;
[First | Rest] ->
index_fold_loop(Rest, With(Acc, First, Index), With, Index + 1)
end.
-file("src/gleam/list.gleam", 799).
?DOC(
" Like fold but the folding function also receives the index of the current element.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" [\"a\", \"b\", \"c\"]\n"
" |> index_fold(\"\", fn(acc, item, index) {\n"
" acc <> int.to_string(index) <> \":\" <> item <> \" \"\n"
" })\n"
" // -> \"0:a 1:b 2:c\"\n"
" ```\n"
"\n"
" ```gleam\n"
" [10, 20, 30]\n"
" |> index_fold(0, fn(acc, item, index) { acc + item * index })\n"
" // -> 80\n"
" ```\n"
).
-spec index_fold(list(AEY), AFA, fun((AFA, AEY, integer()) -> AFA)) -> AFA.
index_fold(List, Initial, Fun) ->
index_fold_loop(List, Initial, Fun, 0).
-file("src/gleam/list.gleam", 839).
?DOC(
" A variant of fold that might fail.\n"
"\n"
" The folding function should return `Result(accumulator, error)`.\n"
" If the returned value is `Ok(accumulator)` try_fold will try the next value in the list.\n"
" If the returned value is `Error(error)` try_fold will stop and return that error.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" [1, 2, 3, 4]\n"
" |> try_fold(0, fn(acc, i) {\n"
" case i < 3 {\n"
" True -> Ok(acc + i)\n"
" False -> Error(Nil)\n"
" }\n"
" })\n"
" // -> Error(Nil)\n"
" ```\n"
).
-spec try_fold(list(AFE), AFG, fun((AFG, AFE) -> {ok, AFG} | {error, AFH})) -> {ok,
AFG} |
{error, AFH}.
try_fold(List, Initial, Fun) ->
case List of
[] ->
{ok, Initial};
[First | Rest] ->
case Fun(Initial, First) of
{ok, Result} ->
try_fold(Rest, Result, Fun);
{error, _} = Error ->
Error
end
end.
-file("src/gleam/list.gleam", 878).
?DOC(
" A variant of fold that allows to stop folding earlier.\n"
"\n"
" The folding function should return `ContinueOrStop(accumulator)`.\n"
" If the returned value is `Continue(accumulator)` fold_until will try the next value in the list.\n"
" If the returned value is `Stop(accumulator)` fold_until will stop and return that accumulator.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" [1, 2, 3, 4]\n"
" |> fold_until(0, fn(acc, i) {\n"
" case i < 3 {\n"
" True -> Continue(acc + i)\n"
" False -> Stop(acc)\n"
" }\n"
" })\n"
" // -> 3\n"
" ```\n"
).
-spec fold_until(list(AFM), AFO, fun((AFO, AFM) -> continue_or_stop(AFO))) -> AFO.
fold_until(List, Initial, Fun) ->
case List of
[] ->
Initial;
[First | Rest] ->
case Fun(Initial, First) of
{continue, Next_accumulator} ->
fold_until(Rest, Next_accumulator, Fun);
{stop, B} ->
B
end
end.
-file("src/gleam/list.gleam", 915).
?DOC(
" Finds the first element in a given list for which the given function returns\n"
" `True`.\n"
"\n"
" Returns `Error(Nil)` if no such element is found.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" find([1, 2, 3], fn(x) { x > 2 })\n"
" // -> Ok(3)\n"
" ```\n"
"\n"
" ```gleam\n"
" find([1, 2, 3], fn(x) { x > 4 })\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" find([], fn(_) { True })\n"
" // -> Error(Nil)\n"
" ```\n"
).
-spec find(list(AFQ), fun((AFQ) -> boolean())) -> {ok, AFQ} | {error, nil}.
find(List, Is_desired) ->
case List of
[] ->
{error, nil};
[First | Rest] ->
case Is_desired(First) of
true ->
{ok, First};
false ->
find(Rest, Is_desired)
end
end.
-file("src/gleam/list.gleam", 951).
?DOC(
" Finds the first element in a given list for which the given function returns\n"
" `Ok(new_value)`, then returns the wrapped `new_value`.\n"
"\n"
" Returns `Error(Nil)` if no such element is found.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" find_map([[], [2], [3]], first)\n"
" // -> Ok(2)\n"
" ```\n"
"\n"
" ```gleam\n"
" find_map([[], []], first)\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" find_map([], first)\n"
" // -> Error(Nil)\n"
" ```\n"
).
-spec find_map(list(AFU), fun((AFU) -> {ok, AFW} | {error, any()})) -> {ok, AFW} |
{error, nil}.
find_map(List, Fun) ->
case List of
[] ->
{error, nil};
[First | Rest] ->
case Fun(First) of
{ok, First@1} ->
{ok, First@1};
{error, _} ->
find_map(Rest, Fun)
end
end.
-file("src/gleam/list.gleam", 986).
?DOC(
" Returns `True` if the given function returns `True` for all the elements in\n"
" the given list. If the function returns `False` for any of the elements it\n"
" immediately returns `False` without checking the rest of the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" all([], fn(x) { x > 3 })\n"
" // -> True\n"
" ```\n"
"\n"
" ```gleam\n"
" all([4, 5], fn(x) { x > 3 })\n"
" // -> True\n"
" ```\n"
"\n"
" ```gleam\n"
" all([4, 3], fn(x) { x > 3 })\n"
" // -> False\n"
" ```\n"
).
-spec all(list(AGC), fun((AGC) -> boolean())) -> boolean().
all(List, Predicate) ->
case List of
[] ->
true;
[First | Rest] ->
case Predicate(First) of
true ->
all(Rest, Predicate);
false ->
false
end
end.
-file("src/gleam/list.gleam", 1023).
?DOC(
" Returns `True` if the given function returns `True` for any the elements in\n"
" the given list. If the function returns `True` for any of the elements it\n"
" immediately returns `True` without checking the rest of the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" any([], fn(x) { x > 3 })\n"
" // -> False\n"
" ```\n"
"\n"
" ```gleam\n"
" any([4, 5], fn(x) { x > 3 })\n"
" // -> True\n"
" ```\n"
"\n"
" ```gleam\n"
" any([4, 3], fn(x) { x > 4 })\n"
" // -> False\n"
" ```\n"
"\n"
" ```gleam\n"
" any([3, 4], fn(x) { x > 3 })\n"
" // -> True\n"
" ```\n"
).
-spec any(list(AGE), fun((AGE) -> boolean())) -> boolean().
any(List, Predicate) ->
case List of
[] ->
false;
[First | Rest] ->
case Predicate(First) of
true ->
true;
false ->
any(Rest, Predicate)
end
end.
-file("src/gleam/list.gleam", 1065).
-spec zip_loop(list(AGL), list(AGN), list({AGL, AGN})) -> list({AGL, AGN}).
zip_loop(One, Other, Acc) ->
case {One, Other} of
{[First_one | Rest_one], [First_other | Rest_other]} ->
zip_loop(Rest_one, Rest_other, [{First_one, First_other} | Acc]);
{_, _} ->
lists:reverse(Acc)
end.
-file("src/gleam/list.gleam", 1061).
?DOC(
" Takes two lists and returns a single list of 2-element tuples.\n"
"\n"
" If one of the lists is longer than the other, the remaining elements from\n"
" the longer list are not used.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" zip([], [])\n"
" // -> []\n"
" ```\n"
"\n"
" ```gleam\n"
" zip([1, 2], [3])\n"
" // -> [#(1, 3)]\n"
" ```\n"
"\n"
" ```gleam\n"
" zip([1], [3, 4])\n"
" // -> [#(1, 3)]\n"
" ```\n"
"\n"
" ```gleam\n"
" zip([1, 2], [3, 4])\n"
" // -> [#(1, 3), #(2, 4)]\n"
" ```\n"
).
-spec zip(list(AGG), list(AGI)) -> list({AGG, AGI}).
zip(List, Other) ->
zip_loop(List, Other, []).
-file("src/gleam/list.gleam", 1106).
-spec strict_zip_loop(list(AGY), list(AHA), list({AGY, AHA})) -> {ok,
list({AGY, AHA})} |
{error, nil}.
strict_zip_loop(One, Other, Acc) ->
case {One, Other} of
{[], []} ->
{ok, lists:reverse(Acc)};
{[], _} ->
{error, nil};
{_, []} ->
{error, nil};
{[First_one | Rest_one], [First_other | Rest_other]} ->
strict_zip_loop(
Rest_one,
Rest_other,
[{First_one, First_other} | Acc]
)
end.
-file("src/gleam/list.gleam", 1099).
?DOC(
" Takes two lists and returns a single list of 2-element tuples.\n"
"\n"
" If one of the lists is longer than the other, an `Error` is returned.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" strict_zip([], [])\n"
" // -> Ok([])\n"
" ```\n"
"\n"
" ```gleam\n"
" strict_zip([1, 2], [3])\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" strict_zip([1], [3, 4])\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" strict_zip([1, 2], [3, 4])\n"
" // -> Ok([#(1, 3), #(2, 4)])\n"
" ```\n"
).
-spec strict_zip(list(AGR), list(AGT)) -> {ok, list({AGR, AGT})} | {error, nil}.
strict_zip(List, Other) ->
strict_zip_loop(List, Other, []).
-file("src/gleam/list.gleam", 1137).
-spec unzip_loop(list({AHL, AHM}), list(AHL), list(AHM)) -> {list(AHL),
list(AHM)}.
unzip_loop(Input, One, Other) ->
case Input of
[] ->
{lists:reverse(One), lists:reverse(Other)};
[{First_one, First_other} | Rest] ->
unzip_loop(Rest, [First_one | One], [First_other | Other])
end.
-file("src/gleam/list.gleam", 1133).
?DOC(
" Takes a single list of 2-element tuples and returns two lists.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" unzip([#(1, 2), #(3, 4)])\n"
" // -> #([1, 3], [2, 4])\n"
" ```\n"
"\n"
" ```gleam\n"
" unzip([])\n"
" // -> #([], [])\n"
" ```\n"
).
-spec unzip(list({AHG, AHH})) -> {list(AHG), list(AHH)}.
unzip(Input) ->
unzip_loop(Input, [], []).
-file("src/gleam/list.gleam", 1172).
-spec intersperse_loop(list(AHV), AHV, list(AHV)) -> list(AHV).
intersperse_loop(List, Separator, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
intersperse_loop(Rest, Separator, [First, Separator | Acc])
end.
-file("src/gleam/list.gleam", 1165).
?DOC(
" Inserts a given value between each existing element in a given list.\n"
"\n"
" This function runs in linear time and copies the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" intersperse([1, 1, 1], 2)\n"
" // -> [1, 2, 1, 2, 1]\n"
" ```\n"
"\n"
" ```gleam\n"
" intersperse([], 2)\n"
" // -> []\n"
" ```\n"
).
-spec intersperse(list(AHS), AHS) -> list(AHS).
intersperse(List, Elem) ->
case List of
[] ->
List;
[_] ->
List;
[First | Rest] ->
intersperse_loop(Rest, Elem, [First])
end.
-file("src/gleam/list.gleam", 1195).
-spec unique_loop(list(AIC), gleam@dict:dict(AIC, nil), list(AIC)) -> list(AIC).
unique_loop(List, Seen, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
case gleam@dict:has_key(Seen, First) of
true ->
unique_loop(Rest, Seen, Acc);
false ->
unique_loop(
Rest,
gleam@dict:insert(Seen, First, nil),
[First | Acc]
)
end
end.
-file("src/gleam/list.gleam", 1191).
?DOC(
" Removes any duplicate elements from a given list.\n"
"\n"
" This function returns in loglinear time.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" unique([1, 1, 1, 4, 7, 3, 3, 4])\n"
" // -> [1, 4, 7, 3]\n"
" ```\n"
).
-spec unique(list(AHZ)) -> list(AHZ).
unique(List) ->
unique_loop(List, maps:new(), []).
-file("src/gleam/list.gleam", 1281).
?DOC(
" Given a list it returns slices of it that are locally sorted in ascending\n"
" order.\n"
"\n"
" Imagine you have this list:\n"
"\n"
" ```\n"
" [1, 2, 3, 2, 1, 0]\n"
" ^^^^^^^ ^^^^^^^ This is a slice in descending order\n"
" |\n"
" | This is a slice that is sorted in ascending order\n"
" ```\n"
"\n"
" So the produced result will contain these two slices, each one sorted in\n"
" ascending order: `[[1, 2, 3], [0, 1, 2]]`.\n"
"\n"
" - `growing` is an accumulator with the current slice being grown\n"
" - `direction` is the growing direction of the slice being grown, it could\n"
" either be ascending or strictly descending\n"
" - `prev` is the previous element that needs to be added to the growing slice\n"
" it is carried around to check whether we have to keep growing the current\n"
" slice or not\n"
" - `acc` is the accumulator containing the slices sorted in ascending order\n"
).
-spec sequences(
list(AIL),
fun((AIL, AIL) -> gleam@order:order()),
list(AIL),
sorting(),
AIL,
list(list(AIL))
) -> list(list(AIL)).
sequences(List, Compare, Growing, Direction, Prev, Acc) ->
Growing@1 = [Prev | Growing],
case List of
[] ->
case Direction of
ascending ->
[lists:reverse(Growing@1) | Acc];
descending ->
[Growing@1 | Acc]
end;
[New | Rest] ->
case {Compare(Prev, New), Direction} of
{gt, descending} ->
sequences(Rest, Compare, Growing@1, Direction, New, Acc);
{lt, ascending} ->
sequences(Rest, Compare, Growing@1, Direction, New, Acc);
{eq, ascending} ->
sequences(Rest, Compare, Growing@1, Direction, New, Acc);
{gt, ascending} ->
Acc@1 = case Direction of
ascending ->
[lists:reverse(Growing@1) | Acc];
descending ->
[Growing@1 | Acc]
end,
case Rest of
[] ->
[[New] | Acc@1];
[Next | Rest@1] ->
Direction@1 = case Compare(New, Next) of
lt ->
ascending;
eq ->
ascending;
gt ->
descending
end,
sequences(
Rest@1,
Compare,
[New],
Direction@1,
Next,
Acc@1
)
end;
{lt, descending} ->
Acc@1 = case Direction of
ascending ->
[lists:reverse(Growing@1) | Acc];
descending ->
[Growing@1 | Acc]
end,
case Rest of
[] ->
[[New] | Acc@1];
[Next | Rest@1] ->
Direction@1 = case Compare(New, Next) of
lt ->
ascending;
eq ->
ascending;
gt ->
descending
end,
sequences(
Rest@1,
Compare,
[New],
Direction@1,
Next,
Acc@1
)
end;
{eq, descending} ->
Acc@1 = case Direction of
ascending ->
[lists:reverse(Growing@1) | Acc];
descending ->
[Growing@1 | Acc]
end,
case Rest of
[] ->
[[New] | Acc@1];
[Next | Rest@1] ->
Direction@1 = case Compare(New, Next) of
lt ->
ascending;
eq ->
ascending;
gt ->
descending
end,
sequences(
Rest@1,
Compare,
[New],
Direction@1,
Next,
Acc@1
)
end
end
end.
-file("src/gleam/list.gleam", 1429).
?DOC(
" Merges two lists sorted in ascending order into a single list sorted in\n"
" descending order according to the given comparator function.\n"
"\n"
" This reversing of the sort order is not avoidable if we want to implement\n"
" merge as a tail recursive function. We could reverse the accumulator before\n"
" returning it but that would end up being less efficient; so the merging\n"
" algorithm has to play around this.\n"
).
-spec merge_ascendings(
list(AJI),
list(AJI),
fun((AJI, AJI) -> gleam@order:order()),
list(AJI)
) -> list(AJI).
merge_ascendings(List1, List2, Compare, Acc) ->
case {List1, List2} of
{[], List} ->
lists:reverse(List, Acc);
{List, []} ->
lists:reverse(List, Acc);
{[First1 | Rest1], [First2 | Rest2]} ->
case Compare(First1, First2) of
lt ->
merge_ascendings(Rest1, List2, Compare, [First1 | Acc]);
gt ->
merge_ascendings(List1, Rest2, Compare, [First2 | Acc]);
eq ->
merge_ascendings(List1, Rest2, Compare, [First2 | Acc])
end
end.
-file("src/gleam/list.gleam", 1382).
?DOC(
" Given a list of ascending lists, it merges adjacent pairs into a single\n"
" descending list, halving their number.\n"
" It returns a list of the remaining descending lists.\n"
).
-spec merge_ascending_pairs(
list(list(AIW)),
fun((AIW, AIW) -> gleam@order:order()),
list(list(AIW))
) -> list(list(AIW)).
merge_ascending_pairs(Sequences, Compare, Acc) ->
case Sequences of
[] ->
lists:reverse(Acc);
[Sequence] ->
lists:reverse([lists:reverse(Sequence) | Acc]);
[Ascending1, Ascending2 | Rest] ->
Descending = merge_ascendings(Ascending1, Ascending2, Compare, []),
merge_ascending_pairs(Rest, Compare, [Descending | Acc])
end.
-file("src/gleam/list.gleam", 1456).
?DOC(
" This is exactly the same as merge_ascendings but mirrored: it merges two\n"
" lists sorted in descending order into a single list sorted in ascending\n"
" order according to the given comparator function.\n"
"\n"
" This reversing of the sort order is not avoidable if we want to implement\n"
" merge as a tail recursive function. We could reverse the accumulator before\n"
" returning it but that would end up being less efficient; so the merging\n"
" algorithm has to play around this.\n"
).
-spec merge_descendings(
list(AJN),
list(AJN),
fun((AJN, AJN) -> gleam@order:order()),
list(AJN)
) -> list(AJN).
merge_descendings(List1, List2, Compare, Acc) ->
case {List1, List2} of
{[], List} ->
lists:reverse(List, Acc);
{List, []} ->
lists:reverse(List, Acc);
{[First1 | Rest1], [First2 | Rest2]} ->
case Compare(First1, First2) of
lt ->
merge_descendings(List1, Rest2, Compare, [First2 | Acc]);
gt ->
merge_descendings(Rest1, List2, Compare, [First1 | Acc]);
eq ->
merge_descendings(Rest1, List2, Compare, [First1 | Acc])
end
end.
-file("src/gleam/list.gleam", 1404).
?DOC(" This is the same as merge_ascending_pairs but flipped for descending lists.\n").
-spec merge_descending_pairs(
list(list(AJC)),
fun((AJC, AJC) -> gleam@order:order()),
list(list(AJC))
) -> list(list(AJC)).
merge_descending_pairs(Sequences, Compare, Acc) ->
case Sequences of
[] ->
lists:reverse(Acc);
[Sequence] ->
lists:reverse([lists:reverse(Sequence) | Acc]);
[Descending1, Descending2 | Rest] ->
Ascending = merge_descendings(Descending1, Descending2, Compare, []),
merge_descending_pairs(Rest, Compare, [Ascending | Acc])
end.
-file("src/gleam/list.gleam", 1348).
?DOC(
" Given some some sorted sequences (assumed to be sorted in `direction`) it\n"
" merges them all together until we're left with just a list sorted in\n"
" ascending order.\n"
).
-spec merge_all(
list(list(AIS)),
sorting(),
fun((AIS, AIS) -> gleam@order:order())
) -> list(AIS).
merge_all(Sequences, Direction, Compare) ->
case {Sequences, Direction} of
{[], _} ->
[];
{[Sequence], ascending} ->
Sequence;
{[Sequence@1], descending} ->
lists:reverse(Sequence@1);
{_, ascending} ->
Sequences@1 = merge_ascending_pairs(Sequences, Compare, []),
merge_all(Sequences@1, descending, Compare);
{_, descending} ->
Sequences@2 = merge_descending_pairs(Sequences, Compare, []),
merge_all(Sequences@2, ascending, Compare)
end.
-file("src/gleam/list.gleam", 1219).
?DOC(
" Sorts from smallest to largest based upon the ordering specified by a given\n"
" function.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" import gleam/int\n"
"\n"
" sort([4, 3, 6, 5, 4, 1, 2], by: int.compare)\n"
" // -> [1, 2, 3, 4, 4, 5, 6]\n"
" ```\n"
).
-spec sort(list(AII), fun((AII, AII) -> gleam@order:order())) -> list(AII).
sort(List, Compare) ->
case List of
[] ->
[];
[X] ->
[X];
[X@1, Y | Rest] ->
Direction = case Compare(X@1, Y) of
lt ->
ascending;
eq ->
ascending;
gt ->
descending
end,
Sequences = sequences(Rest, Compare, [X@1], Direction, Y, []),
merge_all(Sequences, ascending, Compare)
end.
-file("src/gleam/list.gleam", 1496).
-spec range_loop(integer(), integer(), list(integer())) -> list(integer()).
range_loop(Start, Stop, Acc) ->
case gleam@int:compare(Start, Stop) of
eq ->
[Stop | Acc];
gt ->
range_loop(Start, Stop + 1, [Stop | Acc]);
lt ->
range_loop(Start, Stop - 1, [Stop | Acc])
end.
-file("src/gleam/list.gleam", 1492).
?DOC(
" Creates a list of ints ranging from a given start and finish.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" range(0, 0)\n"
" // -> [0]\n"
" ```\n"
"\n"
" ```gleam\n"
" range(0, 5)\n"
" // -> [0, 1, 2, 3, 4, 5]\n"
" ```\n"
"\n"
" ```gleam\n"
" range(1, -5)\n"
" // -> [1, 0, -1, -2, -3, -4, -5]\n"
" ```\n"
).
-spec range(integer(), integer()) -> list(integer()).
range(Start, Stop) ->
range_loop(Start, Stop, []).
-file("src/gleam/list.gleam", 1522).
-spec repeat_loop(AJX, integer(), list(AJX)) -> list(AJX).
repeat_loop(Item, Times, Acc) ->
case Times =< 0 of
true ->
Acc;
false ->
repeat_loop(Item, Times - 1, [Item | Acc])
end.
-file("src/gleam/list.gleam", 1518).
?DOC(
" Builds a list of a given value a given number of times.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" repeat(\"a\", times: 0)\n"
" // -> []\n"
" ```\n"
"\n"
" ```gleam\n"
" repeat(\"a\", times: 5)\n"
" // -> [\"a\", \"a\", \"a\", \"a\", \"a\"]\n"
" ```\n"
).
-spec repeat(AJV, integer()) -> list(AJV).
repeat(A, Times) ->
repeat_loop(A, Times, []).
-file("src/gleam/list.gleam", 1555).
-spec split_loop(list(AKE), integer(), list(AKE)) -> {list(AKE), list(AKE)}.
split_loop(List, N, Taken) ->
case N =< 0 of
true ->
{lists:reverse(Taken), List};
false ->
case List of
[] ->
{lists:reverse(Taken), []};
[First | Rest] ->
split_loop(Rest, N - 1, [First | Taken])
end
end.
-file("src/gleam/list.gleam", 1551).
?DOC(
" Splits a list in two before the given index.\n"
"\n"
" If the list is not long enough to have the given index the before list will\n"
" be the input list, and the after list will be empty.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" split([6, 7, 8, 9], 0)\n"
" // -> #([], [6, 7, 8, 9])\n"
" ```\n"
"\n"
" ```gleam\n"
" split([6, 7, 8, 9], 2)\n"
" // -> #([6, 7], [8, 9])\n"
" ```\n"
"\n"
" ```gleam\n"
" split([6, 7, 8, 9], 4)\n"
" // -> #([6, 7, 8, 9], [])\n"
" ```\n"
).
-spec split(list(AKA), integer()) -> {list(AKA), list(AKA)}.
split(List, Index) ->
split_loop(List, Index, []).
-file("src/gleam/list.gleam", 1591).
-spec split_while_loop(list(AKN), fun((AKN) -> boolean()), list(AKN)) -> {list(AKN),
list(AKN)}.
split_while_loop(List, F, Acc) ->
case List of
[] ->
{lists:reverse(Acc), []};
[First | Rest] ->
case F(First) of
true ->
split_while_loop(Rest, F, [First | Acc]);
false ->
{lists:reverse(Acc), List}
end
end.
-file("src/gleam/list.gleam", 1584).
?DOC(
" Splits a list in two before the first element that a given function returns\n"
" `False` for.\n"
"\n"
" If the function returns `True` for all elements the first list will be the\n"
" input list, and the second list will be empty.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" split_while([1, 2, 3, 4, 5], fn(x) { x <= 3 })\n"
" // -> #([1, 2, 3], [4, 5])\n"
" ```\n"
"\n"
" ```gleam\n"
" split_while([1, 2, 3, 4, 5], fn(x) { x <= 5 })\n"
" // -> #([1, 2, 3, 4, 5], [])\n"
" ```\n"
).
-spec split_while(list(AKJ), fun((AKJ) -> boolean())) -> {list(AKJ), list(AKJ)}.
split_while(List, Predicate) ->
split_while_loop(List, Predicate, []).
-file("src/gleam/list.gleam", 1631).
?DOC(
" Given a list of 2-element tuples, finds the first tuple that has a given\n"
" key as the first element and returns the second element.\n"
"\n"
" If no tuple is found with the given key then `Error(Nil)` is returned.\n"
"\n"
" This function may be useful for interacting with Erlang code where lists of\n"
" tuples are common.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" key_find([#(\"a\", 0), #(\"b\", 1)], \"a\")\n"
" // -> Ok(0)\n"
" ```\n"
"\n"
" ```gleam\n"
" key_find([#(\"a\", 0), #(\"b\", 1)], \"b\")\n"
" // -> Ok(1)\n"
" ```\n"
"\n"
" ```gleam\n"
" key_find([#(\"a\", 0), #(\"b\", 1)], \"c\")\n"
" // -> Error(Nil)\n"
" ```\n"
).
-spec key_find(list({AKS, AKT}), AKS) -> {ok, AKT} | {error, nil}.
key_find(Keyword_list, Desired_key) ->
find_map(
Keyword_list,
fun(Keyword) ->
{Key, Value} = Keyword,
case Key =:= Desired_key of
true ->
{ok, Value};
false ->
{error, nil}
end
end
).
-file("src/gleam/list.gleam", 1662).
?DOC(
" Given a list of 2-element tuples, finds all tuples that have a given\n"
" key as the first element and returns the second element.\n"
"\n"
" This function may be useful for interacting with Erlang code where lists of\n"
" tuples are common.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" key_filter([#(\"a\", 0), #(\"b\", 1), #(\"a\", 2)], \"a\")\n"
" // -> [0, 2]\n"
" ```\n"
"\n"
" ```gleam\n"
" key_filter([#(\"a\", 0), #(\"b\", 1)], \"c\")\n"
" // -> []\n"
" ```\n"
).
-spec key_filter(list({AKX, AKY}), AKX) -> list(AKY).
key_filter(Keyword_list, Desired_key) ->
filter_map(
Keyword_list,
fun(Keyword) ->
{Key, Value} = Keyword,
case Key =:= Desired_key of
true ->
{ok, Value};
false ->
{error, nil}
end
end
).
-file("src/gleam/list.gleam", 1702).
-spec key_pop_loop(list({ALH, ALI}), ALH, list({ALH, ALI})) -> {ok,
{ALI, list({ALH, ALI})}} |
{error, nil}.
key_pop_loop(List, Key, Checked) ->
case List of
[] ->
{error, nil};
[{K, V} | Rest] when K =:= Key ->
{ok, {V, lists:reverse(Checked, Rest)}};
[First | Rest@1] ->
key_pop_loop(Rest@1, Key, [First | Checked])
end.
-file("src/gleam/list.gleam", 1698).
?DOC(
" Given a list of 2-element tuples, finds the first tuple that has a given\n"
" key as the first element. This function will return the second element\n"
" of the found tuple and list with tuple removed.\n"
"\n"
" If no tuple is found with the given key then `Error(Nil)` is returned.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" key_pop([#(\"a\", 0), #(\"b\", 1)], \"a\")\n"
" // -> Ok(#(0, [#(\"b\", 1)]))\n"
" ```\n"
"\n"
" ```gleam\n"
" key_pop([#(\"a\", 0), #(\"b\", 1)], \"b\")\n"
" // -> Ok(#(1, [#(\"a\", 0)]))\n"
" ```\n"
"\n"
" ```gleam\n"
" key_pop([#(\"a\", 0), #(\"b\", 1)], \"c\")\n"
" // -> Error(Nil)\n"
" ```\n"
).
-spec key_pop(list({ALB, ALC}), ALB) -> {ok, {ALC, list({ALB, ALC})}} |
{error, nil}.
key_pop(List, Key) ->
key_pop_loop(List, Key, []).
-file("src/gleam/list.gleam", 1736).
-spec key_set_loop(list({ALS, ALT}), ALS, ALT, list({ALS, ALT})) -> list({ALS,
ALT}).
key_set_loop(List, Key, Value, Inspected) ->
case List of
[{K, _} | Rest] when K =:= Key ->
lists:reverse(Inspected, [{K, Value} | Rest]);
[First | Rest@1] ->
key_set_loop(Rest@1, Key, Value, [First | Inspected]);
[] ->
lists:reverse([{Key, Value} | Inspected])
end.
-file("src/gleam/list.gleam", 1732).
?DOC(
" Given a list of 2-element tuples, inserts a key and value into the list.\n"
"\n"
" If there was already a tuple with the key then it is replaced, otherwise it\n"
" is added to the end of the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" key_set([#(5, 0), #(4, 1)], 4, 100)\n"
" // -> [#(5, 0), #(4, 100)]\n"
" ```\n"
"\n"
" ```gleam\n"
" key_set([#(5, 0), #(4, 1)], 1, 100)\n"
" // -> [#(5, 0), #(4, 1), #(1, 100)]\n"
" ```\n"
).
-spec key_set(list({ALO, ALP}), ALO, ALP) -> list({ALO, ALP}).
key_set(List, Key, Value) ->
key_set_loop(List, Key, Value, []).
-file("src/gleam/list.gleam", 1764).
?DOC(
" Calls a function for each element in a list, discarding the return value.\n"
"\n"
" Useful for calling a side effect for every item of a list.\n"
"\n"
" ```gleam\n"
" import gleam/io\n"
"\n"
" each([\"1\", \"2\", \"3\"], io.println)\n"
" // -> Nil\n"
" // 1\n"
" // 2\n"
" // 3\n"
" ```\n"
).
-spec each(list(ALX), fun((ALX) -> any())) -> nil.
each(List, F) ->
case List of
[] ->
nil;
[First | Rest] ->
F(First),
each(Rest, F)
end.
-file("src/gleam/list.gleam", 1790).
?DOC(
" Calls a `Result` returning function for each element in a list, discarding\n"
" the return value. If the function returns `Error` then the iteration is\n"
" stopped and the error is returned.\n"
"\n"
" Useful for calling a side effect for every item of a list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" try_each(\n"
" over: [1, 2, 3],\n"
" with: function_that_might_fail,\n"
" )\n"
" // -> Ok(Nil)\n"
" ```\n"
).
-spec try_each(list(AMA), fun((AMA) -> {ok, any()} | {error, AMD})) -> {ok, nil} |
{error, AMD}.
try_each(List, Fun) ->
case List of
[] ->
{ok, nil};
[First | Rest] ->
case Fun(First) of
{ok, _} ->
try_each(Rest, Fun);
{error, E} ->
{error, E}
end
end.
-file("src/gleam/list.gleam", 1823).
-spec partition_loop(list(BFT), fun((BFT) -> boolean()), list(BFT), list(BFT)) -> {list(BFT),
list(BFT)}.
partition_loop(List, Categorise, Trues, Falses) ->
case List of
[] ->
{lists:reverse(Trues), lists:reverse(Falses)};
[First | Rest] ->
case Categorise(First) of
true ->
partition_loop(Rest, Categorise, [First | Trues], Falses);
false ->
partition_loop(Rest, Categorise, Trues, [First | Falses])
end
end.
-file("src/gleam/list.gleam", 1816).
?DOC(
" Partitions a list into a tuple/pair of lists\n"
" by a given categorisation function.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" import gleam/int\n"
"\n"
" [1, 2, 3, 4, 5] |> partition(int.is_odd)\n"
" // -> #([1, 3, 5], [2, 4])\n"
" ```\n"
).
-spec partition(list(AMI), fun((AMI) -> boolean())) -> {list(AMI), list(AMI)}.
partition(List, Categorise) ->
partition_loop(List, Categorise, [], []).
-file("src/gleam/list.gleam", 1903).
-spec window_loop(list(list(ANP)), list(ANP), integer()) -> list(list(ANP)).
window_loop(Acc, List, N) ->
Window = take(List, N),
case erlang:length(Window) =:= N of
true ->
window_loop([Window | Acc], drop(List, 1), N);
false ->
lists:reverse(Acc)
end.
-file("src/gleam/list.gleam", 1896).
?DOC(
" Returns a list of sliding windows.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" window([1,2,3,4,5], 3)\n"
" // -> [[1, 2, 3], [2, 3, 4], [3, 4, 5]]\n"
" ```\n"
"\n"
" ```gleam\n"
" window([1, 2], 4)\n"
" // -> []\n"
" ```\n"
).
-spec window(list(ANL), integer()) -> list(list(ANL)).
window(List, N) ->
case N =< 0 of
true ->
[];
false ->
window_loop([], List, N)
end.
-file("src/gleam/list.gleam", 1926).
?DOC(
" Returns a list of tuples containing two contiguous elements.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" window_by_2([1,2,3,4])\n"
" // -> [#(1, 2), #(2, 3), #(3, 4)]\n"
" ```\n"
"\n"
" ```gleam\n"
" window_by_2([1])\n"
" // -> []\n"
" ```\n"
).
-spec window_by_2(list(ANV)) -> list({ANV, ANV}).
window_by_2(List) ->
zip(List, drop(List, 1)).
-file("src/gleam/list.gleam", 1939).
?DOC(
" Drops the first elements in a given list for which the predicate function returns `True`.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" drop_while([1, 2, 3, 4], fn (x) { x < 3 })\n"
" // -> [3, 4]\n"
" ```\n"
).
-spec drop_while(list(ANY), fun((ANY) -> boolean())) -> list(ANY).
drop_while(List, Predicate) ->
case List of
[] ->
[];
[First | Rest] ->
case Predicate(First) of
true ->
drop_while(Rest, Predicate);
false ->
[First | Rest]
end
end.
-file("src/gleam/list.gleam", 1969).
-spec take_while_loop(list(AOE), fun((AOE) -> boolean()), list(AOE)) -> list(AOE).
take_while_loop(List, Predicate, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[First | Rest] ->
case Predicate(First) of
true ->
take_while_loop(Rest, Predicate, [First | Acc]);
false ->
lists:reverse(Acc)
end
end.
-file("src/gleam/list.gleam", 1962).
?DOC(
" Takes the first elements in a given list for which the predicate function returns `True`.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" take_while([1, 2, 3, 2, 4], fn (x) { x < 3 })\n"
" // -> [1, 2]\n"
" ```\n"
).
-spec take_while(list(AOB), fun((AOB) -> boolean())) -> list(AOB).
take_while(List, Predicate) ->
take_while_loop(List, Predicate, []).
-file("src/gleam/list.gleam", 2001).
-spec chunk_loop(list(AON), fun((AON) -> AOP), AOP, list(AON), list(list(AON))) -> list(list(AON)).
chunk_loop(List, F, Previous_key, Current_chunk, Acc) ->
case List of
[First | Rest] ->
Key = F(First),
case Key =:= Previous_key of
true ->
chunk_loop(Rest, F, Key, [First | Current_chunk], Acc);
false ->
New_acc = [lists:reverse(Current_chunk) | Acc],
chunk_loop(Rest, F, Key, [First], New_acc)
end;
[] ->
lists:reverse([lists:reverse(Current_chunk) | Acc])
end.
-file("src/gleam/list.gleam", 1994).
?DOC(
" Returns a list of chunks in which\n"
" the return value of calling `f` on each element is the same.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" [1, 2, 2, 3, 4, 4, 6, 7, 7] |> chunk(by: fn(n) { n % 2 })\n"
" // -> [[1], [2, 2], [3], [4, 4, 6], [7, 7]]\n"
" ```\n"
).
-spec chunk(list(AOI), fun((AOI) -> any())) -> list(list(AOI)).
chunk(List, F) ->
case List of
[] ->
[];
[First | Rest] ->
chunk_loop(Rest, F, F(First), [First], [])
end.
-file("src/gleam/list.gleam", 2046).
-spec sized_chunk_loop(
list(AOZ),
integer(),
integer(),
list(AOZ),
list(list(AOZ))
) -> list(list(AOZ)).
sized_chunk_loop(List, Count, Left, Current_chunk, Acc) ->
case List of
[] ->
case Current_chunk of
[] ->
lists:reverse(Acc);
Remaining ->
lists:reverse([lists:reverse(Remaining) | Acc])
end;
[First | Rest] ->
Chunk = [First | Current_chunk],
case Left > 1 of
true ->
sized_chunk_loop(Rest, Count, Left - 1, Chunk, Acc);
false ->
sized_chunk_loop(
Rest,
Count,
Count,
[],
[lists:reverse(Chunk) | Acc]
)
end
end.
-file("src/gleam/list.gleam", 2042).
?DOC(
" Returns a list of chunks containing `count` elements each.\n"
"\n"
" If the last chunk does not have `count` elements, it is instead\n"
" a partial chunk, with less than `count` elements.\n"
"\n"
" For any `count` less than 1 this function behaves as if it was set to 1.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" [1, 2, 3, 4, 5, 6] |> sized_chunk(into: 2)\n"
" // -> [[1, 2], [3, 4], [5, 6]]\n"
" ```\n"
"\n"
" ```gleam\n"
" [1, 2, 3, 4, 5, 6, 7, 8] |> sized_chunk(into: 3)\n"
" // -> [[1, 2, 3], [4, 5, 6], [7, 8]]\n"
" ```\n"
).
-spec sized_chunk(list(AOV), integer()) -> list(list(AOV)).
sized_chunk(List, Count) ->
sized_chunk_loop(List, Count, Count, [], []).
-file("src/gleam/list.gleam", 2090).
?DOC(
" This function acts similar to fold, but does not take an initial state.\n"
" Instead, it starts from the first element in the list\n"
" and combines it with each subsequent element in turn using the given\n"
" function. The function is called as `fun(accumulator, current_element)`.\n"
"\n"
" Returns `Ok` to indicate a successful run, and `Error` if called on an\n"
" empty list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" [] |> reduce(fn(acc, x) { acc + x })\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" [1, 2, 3, 4, 5] |> reduce(fn(acc, x) { acc + x })\n"
" // -> Ok(15)\n"
" ```\n"
).
-spec reduce(list(APG), fun((APG, APG) -> APG)) -> {ok, APG} | {error, nil}.
reduce(List, Fun) ->
case List of
[] ->
{error, nil};
[First | Rest] ->
{ok, fold(Rest, First, Fun)}
end.
-file("src/gleam/list.gleam", 2114).
-spec scan_loop(list(APO), APQ, list(APQ), fun((APQ, APO) -> APQ)) -> list(APQ).
scan_loop(List, Accumulator, Accumulated, Fun) ->
case List of
[] ->
lists:reverse(Accumulated);
[First | Rest] ->
Next = Fun(Accumulator, First),
scan_loop(Rest, Next, [Next | Accumulated], Fun)
end.
-file("src/gleam/list.gleam", 2106).
?DOC(
" Similar to `fold`, but yields the state of the accumulator at each stage.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" scan(over: [1, 2, 3], from: 100, with: fn(acc, i) { acc + i })\n"
" // -> [101, 103, 106]\n"
" ```\n"
).
-spec scan(list(APK), APM, fun((APM, APK) -> APM)) -> list(APM).
scan(List, Initial, Fun) ->
scan_loop(List, Initial, [], Fun).
-file("src/gleam/list.gleam", 2147).
?DOC(
" Returns the last element in the given list.\n"
"\n"
" Returns `Error(Nil)` if the list is empty.\n"
"\n"
" This function runs in linear time.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" last([])\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" ```gleam\n"
" last([1, 2, 3, 4, 5])\n"
" // -> Ok(5)\n"
" ```\n"
).
-spec last(list(APT)) -> {ok, APT} | {error, nil}.
last(List) ->
case List of
[] ->
{error, nil};
[Last] ->
{ok, Last};
[_ | Rest] ->
last(Rest)
end.
-file("src/gleam/list.gleam", 2169).
?DOC(
" Return unique combinations of elements in the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" combinations([1, 2, 3], 2)\n"
" // -> [[1, 2], [1, 3], [2, 3]]\n"
" ```\n"
"\n"
" ```gleam\n"
" combinations([1, 2, 3, 4], 3)\n"
" // -> [[1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]]\n"
" ```\n"
).
-spec combinations(list(APX), integer()) -> list(list(APX)).
combinations(Items, N) ->
case {N, Items} of
{0, _} ->
[[]];
{_, []} ->
[];
{_, [First | Rest]} ->
_pipe = Rest,
_pipe@1 = combinations(_pipe, N - 1),
_pipe@2 = map(
_pipe@1,
fun(Combination) -> [First | Combination] end
),
_pipe@3 = lists:reverse(_pipe@2),
fold(_pipe@3, combinations(Rest, N), fun(Acc, C) -> [C | Acc] end)
end.
-file("src/gleam/list.gleam", 2195).
-spec combination_pairs_loop(list(AQE), list({AQE, AQE})) -> list({AQE, AQE}).
combination_pairs_loop(Items, Acc) ->
case Items of
[] ->
lists:reverse(Acc);
[First | Rest] ->
First_combinations = map(Rest, fun(Other) -> {First, Other} end),
Acc@1 = lists:reverse(First_combinations, Acc),
combination_pairs_loop(Rest, Acc@1)
end.
-file("src/gleam/list.gleam", 2191).
?DOC(
" Return unique pair combinations of elements in the list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" combination_pairs([1, 2, 3])\n"
" // -> [#(1, 2), #(1, 3), #(2, 3)]\n"
" ```\n"
).
-spec combination_pairs(list(AQB)) -> list({AQB, AQB}).
combination_pairs(Items) ->
combination_pairs_loop(Items, []).
-file("src/gleam/list.gleam", 2251).
-spec take_firsts(list(list(AQY)), list(AQY), list(list(AQY))) -> {list(AQY),
list(list(AQY))}.
take_firsts(Rows, Column, Remaining_rows) ->
case Rows of
[] ->
{lists:reverse(Column), lists:reverse(Remaining_rows)};
[[] | Rest] ->
take_firsts(Rest, Column, Remaining_rows);
[[First | Remaining_row] | Rest_rows] ->
Remaining_rows@1 = [Remaining_row | Remaining_rows],
take_firsts(Rest_rows, [First | Column], Remaining_rows@1)
end.
-file("src/gleam/list.gleam", 2238).
-spec transpose_loop(list(list(AQR)), list(list(AQR))) -> list(list(AQR)).
transpose_loop(Rows, Columns) ->
case Rows of
[] ->
lists:reverse(Columns);
_ ->
{Column, Rest} = take_firsts(Rows, [], []),
case Column of
[_ | _] ->
transpose_loop(Rest, [Column | Columns]);
[] ->
transpose_loop(Rest, Columns)
end
end.
-file("src/gleam/list.gleam", 2234).
?DOC(
" Transpose rows and columns of the list of lists.\n"
"\n"
" Notice: This function is not tail recursive,\n"
" and thus may exceed stack size if called,\n"
" with large lists (on the JavaScript target).\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" transpose([[1, 2, 3], [101, 102, 103]])\n"
" // -> [[1, 101], [2, 102], [3, 103]]\n"
" ```\n"
).
-spec transpose(list(list(AQM))) -> list(list(AQM)).
transpose(List_of_lists) ->
transpose_loop(List_of_lists, []).
-file("src/gleam/list.gleam", 2215).
?DOC(
" Make a list alternating the elements from the given lists\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" interleave([[1, 2], [101, 102], [201, 202]])\n"
" // -> [1, 101, 201, 2, 102, 202]\n"
" ```\n"
).
-spec interleave(list(list(AQI))) -> list(AQI).
interleave(List) ->
_pipe = List,
_pipe@1 = transpose(_pipe),
lists:append(_pipe@1).
-file("src/gleam/list.gleam", 2284).
-spec shuffle_pair_unwrap_loop(list({float(), ARK}), list(ARK)) -> list(ARK).
shuffle_pair_unwrap_loop(List, Acc) ->
case List of
[] ->
Acc;
[Elem_pair | Enumerable] ->
shuffle_pair_unwrap_loop(
Enumerable,
[erlang:element(2, Elem_pair) | Acc]
)
end.
-file("src/gleam/list.gleam", 2292).
-spec do_shuffle_by_pair_indexes(list({float(), ARO})) -> list({float(), ARO}).
do_shuffle_by_pair_indexes(List_of_pairs) ->
sort(
List_of_pairs,
fun(A_pair, B_pair) ->
gleam@float:compare(
erlang:element(1, A_pair),
erlang:element(1, B_pair)
)
end
).
-file("src/gleam/list.gleam", 2277).
?DOC(
" Takes a list, randomly sorts all items and returns the shuffled list.\n"
"\n"
" This function uses `float.random` to decide the order of the elements.\n"
"\n"
" ## Example\n"
"\n"
" ```gleam\n"
" range(1, 10) |> shuffle()\n"
" // -> [1, 6, 9, 10, 3, 8, 4, 2, 7, 5]\n"
" ```\n"
).
-spec shuffle(list(ARH)) -> list(ARH).
shuffle(List) ->
_pipe = List,
_pipe@1 = fold(_pipe, [], fun(Acc, A) -> [{rand:uniform(), A} | Acc] end),
_pipe@2 = do_shuffle_by_pair_indexes(_pipe@1),
shuffle_pair_unwrap_loop(_pipe@2, []).
-file("src/gleam/list.gleam", 2324).
-spec max_loop(list(ARY), fun((ARY, ARY) -> gleam@order:order()), ARY) -> ARY.
max_loop(List, Compare, Max) ->
case List of
[] ->
Max;
[First | Rest] ->
case Compare(First, Max) of
gt ->
max_loop(Rest, Compare, First);
lt ->
max_loop(Rest, Compare, Max);
eq ->
max_loop(Rest, Compare, Max)
end
end.
-file("src/gleam/list.gleam", 2314).
?DOC(
" Takes a list and a comparator, and returns the maximum element in the list\n"
"\n"
"\n"
" ## Example\n"
"\n"
" ```gleam\n"
" range(1, 10) |> list.max(int.compare)\n"
" // -> Ok(10)\n"
" ```\n"
"\n"
" ```gleam\n"
" [\"a\", \"c\", \"b\"] |> list.max(string.compare)\n"
" // -> Ok(\"c\")\n"
" ```\n"
).
-spec max(list(ARR), fun((ARR, ARR) -> gleam@order:order())) -> {ok, ARR} |
{error, nil}.
max(List, Compare) ->
case List of
[] ->
{error, nil};
[First | Rest] ->
{ok, max_loop(Rest, Compare, First)}
end.
-file("src/gleam/list.gleam", 2405).
-spec build_reservoir_loop(
list(ASN),
integer(),
gleam@dict:dict(integer(), ASN)
) -> {gleam@dict:dict(integer(), ASN), list(ASN)}.
build_reservoir_loop(List, Size, Reservoir) ->
Reservoir_size = maps:size(Reservoir),
case Reservoir_size >= Size of
true ->
{Reservoir, List};
false ->
case List of
[] ->
{Reservoir, []};
[First | Rest] ->
Reservoir@1 = gleam@dict:insert(
Reservoir,
Reservoir_size,
First
),
build_reservoir_loop(Rest, Size, Reservoir@1)
end
end.
-file("src/gleam/list.gleam", 2401).
?DOC(
" Builds the initial reservoir used by Algorithm L.\n"
" This is a dictionary with keys ranging from `0` up to `n - 1` where each\n"
" value is the corresponding element at that position in `list`.\n"
"\n"
" This also returns the remaining elements of `list` that didn't end up in\n"
" the reservoir.\n"
).
-spec build_reservoir(list(ASI), integer()) -> {gleam@dict:dict(integer(), ASI),
list(ASI)}.
build_reservoir(List, N) ->
build_reservoir_loop(List, N, maps:new()).
-file("src/gleam/list.gleam", 2389).
-spec log_random() -> float().
log_random() ->
Random@1 = case gleam@float:logarithm(
rand:uniform() + 2.2250738585072014e-308
) of
{ok, Random} -> Random;
_assert_fail ->
erlang:error(#{gleam_error => let_assert,
message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
file => <<?FILEPATH/utf8>>,
module => <<"gleam/list"/utf8>>,
function => <<"log_random"/utf8>>,
line => 2390,
value => _assert_fail,
start => 56050,
'end' => 56121,
pattern_start => 56061,
pattern_end => 56071})
end,
Random@1.
-file("src/gleam/list.gleam", 2366).
-spec sample_loop(
list(ASC),
gleam@dict:dict(integer(), ASC),
integer(),
float()
) -> gleam@dict:dict(integer(), ASC).
sample_loop(List, Reservoir, N, W) ->
Skip = begin
Log@1 = case gleam@float:logarithm(1.0 - W) of
{ok, Log} -> Log;
_assert_fail ->
erlang:error(#{gleam_error => let_assert,
message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
file => <<?FILEPATH/utf8>>,
module => <<"gleam/list"/utf8>>,
function => <<"sample_loop"/utf8>>,
line => 2373,
value => _assert_fail,
start => 55611,
'end' => 55657,
pattern_start => 55622,
pattern_end => 55629})
end,
erlang:round(math:floor(case Log@1 of
+0.0 -> +0.0;
-0.0 -> -0.0;
Gleam@denominator -> log_random() / Gleam@denominator
end))
end,
case drop(List, Skip) of
[] ->
Reservoir;
[First | Rest] ->
Reservoir@1 = gleam@dict:insert(
Reservoir,
gleam@int:random(N),
First
),
W@1 = W * math:exp(case erlang:float(N) of
+0.0 -> +0.0;
-0.0 -> -0.0;
Gleam@denominator@1 -> log_random() / Gleam@denominator@1
end),
sample_loop(Rest, Reservoir@1, N, W@1)
end.
-file("src/gleam/list.gleam", 2348).
?DOC(
" Returns a random sample of up to n elements from a list using reservoir\n"
" sampling via [Algorithm L](https://en.wikipedia.org/wiki/Reservoir_sampling#Optimal:_Algorithm_L).\n"
" Returns an empty list if the sample size is less than or equal to 0.\n"
"\n"
" Order is not random, only selection is.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" reservoir_sample([1, 2, 3, 4, 5], 3)\n"
" // -> [2, 4, 5] // A random sample of 3 items\n"
" ```\n"
).
-spec sample(list(ARZ), integer()) -> list(ARZ).
sample(List, N) ->
{Reservoir, Rest} = build_reservoir(List, N),
case gleam@dict:is_empty(Reservoir) of
true ->
[];
false ->
W = math:exp(case erlang:float(N) of
+0.0 -> +0.0;
-0.0 -> -0.0;
Gleam@denominator -> log_random() / Gleam@denominator
end),
maps:values(sample_loop(Rest, Reservoir, N, W))
end.
-file("src/gleam/list.gleam", 1850).
-spec permutation_zip(list(AMV), list(AMV), list(list(AMV))) -> list(list(AMV)).
permutation_zip(List, Rest, Acc) ->
case List of
[] ->
lists:reverse(Acc);
[Head | Tail] ->
permutation_prepend(
Head,
permutations(lists:reverse(Rest, Tail)),
Tail,
[Head | Rest],
Acc
)
end.
-file("src/gleam/list.gleam", 1868).
-spec permutation_prepend(
ANC,
list(list(ANC)),
list(ANC),
list(ANC),
list(list(ANC))
) -> list(list(ANC)).
permutation_prepend(El, Permutations, List_1, List_2, Acc) ->
case Permutations of
[] ->
permutation_zip(List_1, List_2, Acc);
[Head | Tail] ->
permutation_prepend(El, Tail, List_1, List_2, [[El | Head] | Acc])
end.
-file("src/gleam/list.gleam", 1843).
?DOC(
" Returns all the permutations of a list.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" permutations([1, 2])\n"
" // -> [[1, 2], [2, 1]]\n"
" ```\n"
).
-spec permutations(list(AMR)) -> list(list(AMR)).
permutations(List) ->
case List of
[] ->
[[]];
L ->
permutation_zip(L, [], [])
end.