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gleam_stdlib
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retired
A standard library for the Gleam programming language
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Files
src/gleam@iterator.erl
-module(gleam@iterator).
-compile(no_auto_import).
-export([unfold/2, repeatedly/1, repeat/1, from_list/1, fold/3, run/1, to_list/1, step/1, take/2, drop/2, map/2, append/2, flatten/1, flat_map/2, filter/2, cycle/1, range/2, find/2, index/1, iterate/2, take_while/2, drop_while/2, scan/3, zip/2, chunk/2, sized_chunk/2, intersperse/2, any/2, all/2, group/2, reduce/2, last/1, empty/0, once/1, single/1, interleave/2, fold_until/3, try_fold/3, first/1, at/2]).
-export_type([action/1, iterator/1, step/2, chunk/2, sized_chunk/1]).
-type action(BCN) :: stop | {continue, BCN, fun(() -> action(BCN))}.
-opaque iterator(BCO) :: {iterator, fun(() -> action(BCO))}.
-type step(BCP, BCQ) :: {next, BCP, BCQ} | done.
-type chunk(BCR, BCS) :: {another_by,
list(BCR),
BCS,
BCR,
fun(() -> action(BCR))} |
{last_by, list(BCR)}.
-type sized_chunk(BCT) :: {another, list(BCT), fun(() -> action(BCT))} |
{last, list(BCT)} |
no_more.
-spec stop() -> action(any()).
stop() ->
stop.
-spec do_unfold(BCY, fun((BCY) -> step(BCZ, BCY))) -> fun(() -> action(BCZ)).
do_unfold(Initial, F) ->
fun() -> case F(Initial) of
{next, X, Acc} ->
{continue, X, do_unfold(Acc, F)};
done ->
stop
end end.
-spec unfold(BDD, fun((BDD) -> step(BDE, BDD))) -> iterator(BDE).
unfold(Initial, F) ->
_pipe = Initial,
_pipe@1 = do_unfold(_pipe, F),
{iterator, _pipe@1}.
-spec repeatedly(fun(() -> BDI)) -> iterator(BDI).
repeatedly(F) ->
unfold(nil, fun(_) -> {next, F(), nil} end).
-spec repeat(BDK) -> iterator(BDK).
repeat(X) ->
repeatedly(fun() -> X end).
-spec from_list(list(BDM)) -> iterator(BDM).
from_list(List) ->
Yield = fun(Acc) -> case Acc of
[] ->
done;
[Head | Tail] ->
{next, Head, Tail}
end end,
unfold(List, Yield).
-spec do_fold(fun(() -> action(BDP)), fun((BDR, BDP) -> BDR), BDR) -> BDR.
do_fold(Continuation, F, Accumulator) ->
case Continuation() of
{continue, Elem, Next} ->
do_fold(Next, F, F(Accumulator, Elem));
stop ->
Accumulator
end.
-spec fold(iterator(BDS), BDU, fun((BDU, BDS) -> BDU)) -> BDU.
fold(Iterator, Initial, F) ->
_pipe = erlang:element(2, Iterator),
do_fold(_pipe, F, Initial).
-spec run(iterator(any())) -> nil.
run(Iterator) ->
fold(Iterator, nil, fun(_, _) -> nil end).
-spec to_list(iterator(BDX)) -> list(BDX).
to_list(Iterator) ->
_pipe = Iterator,
_pipe@1 = fold(_pipe, [], fun(Acc, E) -> [E | Acc] end),
gleam@list:reverse(_pipe@1).
-spec step(iterator(BEA)) -> step(BEA, iterator(BEA)).
step(Iterator) ->
case (erlang:element(2, Iterator))() of
stop ->
done;
{continue, E, A} ->
{next, E, {iterator, A}}
end.
-spec do_take(fun(() -> action(BEF)), integer()) -> fun(() -> action(BEF)).
do_take(Continuation, Desired) ->
fun() -> case Desired > 0 of
false ->
stop;
true ->
case Continuation() of
stop ->
stop;
{continue, E, Next} ->
{continue, E, do_take(Next, Desired - 1)}
end
end end.
-spec take(iterator(BEI), integer()) -> iterator(BEI).
take(Iterator, Desired) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_take(_pipe, Desired),
{iterator, _pipe@1}.
-spec do_drop(fun(() -> action(BEL)), integer()) -> action(BEL).
do_drop(Continuation, Desired) ->
case Continuation() of
stop ->
stop;
{continue, E, Next} ->
case Desired > 0 of
true ->
do_drop(Next, Desired - 1);
false ->
{continue, E, Next}
end
end.
-spec drop(iterator(BEO), integer()) -> iterator(BEO).
drop(Iterator, Desired) ->
_pipe = fun() -> do_drop(erlang:element(2, Iterator), Desired) end,
{iterator, _pipe}.
-spec do_map(fun(() -> action(BER)), fun((BER) -> BET)) -> fun(() -> action(BET)).
do_map(Continuation, F) ->
fun() -> case Continuation() of
stop ->
stop;
{continue, E, Continuation@1} ->
{continue, F(E), do_map(Continuation@1, F)}
end end.
-spec map(iterator(BEV), fun((BEV) -> BEX)) -> iterator(BEX).
map(Iterator, F) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_map(_pipe, F),
{iterator, _pipe@1}.
-spec do_append(fun(() -> action(BEZ)), fun(() -> action(BEZ))) -> action(BEZ).
do_append(First, Second) ->
case First() of
{continue, E, First@1} ->
{continue, E, fun() -> do_append(First@1, Second) end};
stop ->
Second()
end.
-spec append(iterator(BFD), iterator(BFD)) -> iterator(BFD).
append(First, Second) ->
_pipe = fun() ->
do_append(erlang:element(2, First), erlang:element(2, Second))
end,
{iterator, _pipe}.
-spec do_flatten(fun(() -> action(iterator(BFH)))) -> action(BFH).
do_flatten(Flattened) ->
case Flattened() of
stop ->
stop;
{continue, It, Next_iterator} ->
do_append(
erlang:element(2, It),
fun() -> do_flatten(Next_iterator) end
)
end.
-spec flatten(iterator(iterator(BFL))) -> iterator(BFL).
flatten(Iterator) ->
_pipe = fun() -> do_flatten(erlang:element(2, Iterator)) end,
{iterator, _pipe}.
-spec flat_map(iterator(BFP), fun((BFP) -> iterator(BFR))) -> iterator(BFR).
flat_map(Iterator, F) ->
_pipe = Iterator,
_pipe@1 = map(_pipe, F),
flatten(_pipe@1).
-spec do_filter(fun(() -> action(BFU)), fun((BFU) -> boolean())) -> action(BFU).
do_filter(Continuation, Predicate) ->
case Continuation() of
stop ->
stop;
{continue, E, Iterator} ->
case Predicate(E) of
true ->
{continue, E, fun() -> do_filter(Iterator, Predicate) end};
false ->
do_filter(Iterator, Predicate)
end
end.
-spec filter(iterator(BFX), fun((BFX) -> boolean())) -> iterator(BFX).
filter(Iterator, Predicate) ->
_pipe = fun() -> do_filter(erlang:element(2, Iterator), Predicate) end,
{iterator, _pipe}.
-spec cycle(iterator(BGA)) -> iterator(BGA).
cycle(Iterator) ->
_pipe = repeat(Iterator),
flatten(_pipe).
-spec range(integer(), integer()) -> iterator(integer()).
range(Start, Stop) ->
case gleam@int:compare(Start, Stop) of
eq ->
once(fun() -> Start end);
gt ->
unfold(Start, fun(Current) -> case Current < Stop of
false ->
{next, Current, Current - 1};
true ->
done
end end);
lt ->
unfold(Start, fun(Current@1) -> case Current@1 > Stop of
false ->
{next, Current@1, Current@1 + 1};
true ->
done
end end)
end.
-spec do_find(fun(() -> action(BGE)), fun((BGE) -> boolean())) -> {ok, BGE} |
{error, nil}.
do_find(Continuation, F) ->
case Continuation() of
stop ->
{error, nil};
{continue, E, Next} ->
case F(E) of
true ->
{ok, E};
false ->
do_find(Next, F)
end
end.
-spec find(iterator(BGI), fun((BGI) -> boolean())) -> {ok, BGI} | {error, nil}.
find(Haystack, Is_desired) ->
_pipe = erlang:element(2, Haystack),
do_find(_pipe, Is_desired).
-spec do_index(fun(() -> action(BGM)), integer()) -> fun(() -> action({integer(),
BGM})).
do_index(Continuation, Next) ->
fun() -> case Continuation() of
stop ->
stop;
{continue, E, Continuation@1} ->
{continue, {Next, E}, do_index(Continuation@1, Next + 1)}
end end.
-spec index(iterator(BGP)) -> iterator({integer(), BGP}).
index(Iterator) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_index(_pipe, 0),
{iterator, _pipe@1}.
-spec iterate(BGS, fun((BGS) -> BGS)) -> iterator(BGS).
iterate(Initial, F) ->
unfold(Initial, fun(Element) -> {next, Element, F(Element)} end).
-spec do_take_while(fun(() -> action(BGU)), fun((BGU) -> boolean())) -> fun(() -> action(BGU)).
do_take_while(Continuation, Predicate) ->
fun() -> case Continuation() of
stop ->
stop;
{continue, E, Next} ->
case Predicate(E) of
false ->
stop;
true ->
{continue, E, do_take_while(Next, Predicate)}
end
end end.
-spec take_while(iterator(BGX), fun((BGX) -> boolean())) -> iterator(BGX).
take_while(Iterator, Predicate) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_take_while(_pipe, Predicate),
{iterator, _pipe@1}.
-spec do_drop_while(fun(() -> action(BHA)), fun((BHA) -> boolean())) -> action(BHA).
do_drop_while(Continuation, Predicate) ->
case Continuation() of
stop ->
stop;
{continue, E, Next} ->
case Predicate(E) of
false ->
{continue, E, Next};
true ->
do_drop_while(Next, Predicate)
end
end.
-spec drop_while(iterator(BHD), fun((BHD) -> boolean())) -> iterator(BHD).
drop_while(Iterator, Predicate) ->
_pipe = fun() -> do_drop_while(erlang:element(2, Iterator), Predicate) end,
{iterator, _pipe}.
-spec do_scan(fun(() -> action(BHG)), fun((BHI, BHG) -> BHI), BHI) -> fun(() -> action(BHI)).
do_scan(Continuation, F, Accumulator) ->
fun() -> case Continuation() of
stop ->
stop;
{continue, El, Next} ->
Accumulated = F(Accumulator, El),
{continue, Accumulated, do_scan(Next, F, Accumulated)}
end end.
-spec scan(iterator(BHK), BHM, fun((BHM, BHK) -> BHM)) -> iterator(BHM).
scan(Iterator, Initial, F) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_scan(_pipe, F, Initial),
{iterator, _pipe@1}.
-spec do_zip(fun(() -> action(BHO)), fun(() -> action(BHQ))) -> fun(() -> action({BHO,
BHQ})).
do_zip(Left, Right) ->
fun() -> case Left() of
stop ->
stop;
{continue, El_left, Next_left} ->
case Right() of
stop ->
stop;
{continue, El_right, Next_right} ->
{continue,
{El_left, El_right},
do_zip(Next_left, Next_right)}
end
end end.
-spec zip(iterator(BHT), iterator(BHV)) -> iterator({BHT, BHV}).
zip(Left, Right) ->
_pipe = do_zip(erlang:element(2, Left), erlang:element(2, Right)),
{iterator, _pipe}.
-spec next_chunk(fun(() -> action(BIB)), fun((BIB) -> BID), BID, list(BIB)) -> chunk(BIB, BID).
next_chunk(Continuation, F, Previous_key, Current_chunk) ->
case Continuation() of
stop ->
{last_by, gleam@list:reverse(Current_chunk)};
{continue, E, Next} ->
Key = F(E),
case Key =:= Previous_key of
true ->
next_chunk(Next, F, Key, [E | Current_chunk]);
false ->
{another_by,
gleam@list:reverse(Current_chunk),
Key,
E,
Next}
end
end.
-spec do_chunk(fun(() -> action(BIH)), fun((BIH) -> BIJ), BIJ, BIH) -> action(list(BIH)).
do_chunk(Continuation, F, Previous_key, Previous_element) ->
case next_chunk(Continuation, F, Previous_key, [Previous_element]) of
{last_by, Chunk} ->
{continue, Chunk, fun stop/0};
{another_by, Chunk@1, Key, El, Next} ->
{continue, Chunk@1, fun() -> do_chunk(Next, F, Key, El) end}
end.
-spec chunk(iterator(BIM), fun((BIM) -> any())) -> iterator(list(BIM)).
chunk(Iterator, F) ->
_pipe = fun() -> case (erlang:element(2, Iterator))() of
stop ->
stop;
{continue, E, Next} ->
do_chunk(Next, F, F(E), E)
end end,
{iterator, _pipe}.
-spec next_sized_chunk(fun(() -> action(BIU)), integer(), list(BIU)) -> sized_chunk(BIU).
next_sized_chunk(Continuation, Left, Current_chunk) ->
case Continuation() of
stop ->
case Current_chunk of
[] ->
no_more;
Remaining ->
{last, gleam@list:reverse(Remaining)}
end;
{continue, E, Next} ->
Chunk = [E | Current_chunk],
case Left > 1 of
false ->
{another, gleam@list:reverse(Chunk), Next};
true ->
next_sized_chunk(Next, Left - 1, Chunk)
end
end.
-spec do_sized_chunk(fun(() -> action(BIY)), integer()) -> fun(() -> action(list(BIY))).
do_sized_chunk(Continuation, Count) ->
fun() -> case next_sized_chunk(Continuation, Count, []) of
no_more ->
stop;
{last, Chunk} ->
{continue, Chunk, fun stop/0};
{another, Chunk@1, Next_element} ->
{continue, Chunk@1, do_sized_chunk(Next_element, Count)}
end end.
-spec sized_chunk(iterator(BJC), integer()) -> iterator(list(BJC)).
sized_chunk(Iterator, Count) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_sized_chunk(_pipe, Count),
{iterator, _pipe@1}.
-spec do_intersperse(fun(() -> action(BJG)), BJG) -> action(BJG).
do_intersperse(Continuation, Separator) ->
case Continuation() of
stop ->
stop;
{continue, E, Next} ->
Next_interspersed = fun() -> do_intersperse(Next, Separator) end,
{continue, Separator, fun() -> {continue, E, Next_interspersed} end}
end.
-spec intersperse(iterator(BJJ), BJJ) -> iterator(BJJ).
intersperse(Iterator, Elem) ->
_pipe = fun() -> case (erlang:element(2, Iterator))() of
stop ->
stop;
{continue, E, Next} ->
{continue, E, fun() -> do_intersperse(Next, Elem) end}
end end,
{iterator, _pipe}.
-spec do_any(fun(() -> action(BJM)), fun((BJM) -> boolean())) -> boolean().
do_any(Continuation, Predicate) ->
case Continuation() of
stop ->
false;
{continue, E, Next} ->
Predicate(E) orelse do_any(Next, Predicate)
end.
-spec any(iterator(BJO), fun((BJO) -> boolean())) -> boolean().
any(Iterator, Predicate) ->
_pipe = erlang:element(2, Iterator),
do_any(_pipe, Predicate).
-spec do_all(fun(() -> action(BJQ)), fun((BJQ) -> boolean())) -> boolean().
do_all(Continuation, Predicate) ->
case Continuation() of
stop ->
true;
{continue, E, Next} ->
Predicate(E) andalso do_all(Next, Predicate)
end.
-spec all(iterator(BJS), fun((BJS) -> boolean())) -> boolean().
all(Iterator, Predicate) ->
_pipe = erlang:element(2, Iterator),
do_all(_pipe, Predicate).
-spec update_group_with(BJU) -> fun((gleam@option:option(list(BJU))) -> list(BJU)).
update_group_with(El) ->
fun(Maybe_group) -> case Maybe_group of
{some, Group} ->
[El | Group];
none ->
[El]
end end.
-spec group_updater(fun((BJY) -> BJZ)) -> fun((gleam@map:map_(BJZ, list(BJY)), BJY) -> gleam@map:map_(BJZ, list(BJY))).
group_updater(F) ->
fun(Groups, Elem) ->
_pipe = Groups,
gleam@map:update(_pipe, F(Elem), update_group_with(Elem))
end.
-spec group(iterator(BKG), fun((BKG) -> BKI)) -> gleam@map:map_(BKI, list(BKG)).
group(Iterator, Key) ->
_pipe = Iterator,
_pipe@1 = fold(_pipe, gleam@map:new(), group_updater(Key)),
gleam@map:map_values(
_pipe@1,
fun(_, Group) -> gleam@list:reverse(Group) end
).
-spec reduce(iterator(BKM), fun((BKM, BKM) -> BKM)) -> {ok, BKM} | {error, nil}.
reduce(Iterator, F) ->
case (erlang:element(2, Iterator))() of
stop ->
{error, nil};
{continue, E, Next} ->
_pipe = do_fold(Next, F, E),
{ok, _pipe}
end.
-spec last(iterator(BKQ)) -> {ok, BKQ} | {error, nil}.
last(Iterator) ->
_pipe = Iterator,
reduce(_pipe, fun(_, Elem) -> Elem end).
-spec empty() -> iterator(any()).
empty() ->
{iterator, fun stop/0}.
-spec once(fun(() -> BKW)) -> iterator(BKW).
once(F) ->
_pipe = fun() -> {continue, F(), fun stop/0} end,
{iterator, _pipe}.
-spec single(BKY) -> iterator(BKY).
single(Elem) ->
once(fun() -> Elem end).
-spec do_interleave(fun(() -> action(BLA)), fun(() -> action(BLA))) -> action(BLA).
do_interleave(Current, Next) ->
case Current() of
stop ->
Next();
{continue, E, Next_other} ->
{continue, E, fun() -> do_interleave(Next, Next_other) end}
end.
-spec interleave(iterator(BLE), iterator(BLE)) -> iterator(BLE).
interleave(Left, Right) ->
_pipe = fun() ->
do_interleave(erlang:element(2, Left), erlang:element(2, Right))
end,
{iterator, _pipe}.
-spec do_fold_until(
fun(() -> action(BLI)),
fun((BLK, BLI) -> gleam@list:continue_or_stop(BLK)),
BLK
) -> BLK.
do_fold_until(Continuation, F, Accumulator) ->
case Continuation() of
stop ->
Accumulator;
{continue, Elem, Next} ->
case F(Accumulator, Elem) of
{continue, Accumulator@1} ->
do_fold_until(Next, F, Accumulator@1);
{stop, Accumulator@2} ->
Accumulator@2
end
end.
-spec fold_until(
iterator(BLM),
BLO,
fun((BLO, BLM) -> gleam@list:continue_or_stop(BLO))
) -> BLO.
fold_until(Iterator, Initial, F) ->
_pipe = erlang:element(2, Iterator),
do_fold_until(_pipe, F, Initial).
-spec do_try_fold(
fun(() -> action(BLQ)),
fun((BLS, BLQ) -> {ok, BLS} | {error, BLT}),
BLS
) -> {ok, BLS} | {error, BLT}.
do_try_fold(Continuation, F, Accumulator) ->
case Continuation() of
stop ->
{ok, Accumulator};
{continue, Elem, Next} ->
case F(Accumulator, Elem) of
{error, _try} -> {error, _try};
{ok, Accumulator@1} ->
do_try_fold(Next, F, Accumulator@1)
end
end.
-spec try_fold(iterator(BLY), BMA, fun((BMA, BLY) -> {ok, BMA} | {error, BMB})) -> {ok,
BMA} |
{error, BMB}.
try_fold(Iterator, Initial, F) ->
_pipe = erlang:element(2, Iterator),
do_try_fold(_pipe, F, Initial).
-spec first(iterator(BMG)) -> {ok, BMG} | {error, nil}.
first(Iterator) ->
case (erlang:element(2, Iterator))() of
stop ->
{error, nil};
{continue, E, _@1} ->
{ok, E}
end.
-spec at(iterator(BMK), integer()) -> {ok, BMK} | {error, nil}.
at(Iterator, Index) ->
_pipe = Iterator,
_pipe@1 = drop(_pipe, Index),
first(_pipe@1).