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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(CQA) :: stop | {continue, CQA, fun(() -> action(CQA))}.
-opaque iterator(CQB) :: {iterator, fun(() -> action(CQB))}.
-type step(CQC, CQD) :: {next, CQC, CQD} | done.
-type chunk(CQE, CQF) :: {another_by,
list(CQE),
CQF,
CQE,
fun(() -> action(CQE))} |
{last_by, list(CQE)}.
-type sized_chunk(CQG) :: {another, list(CQG), fun(() -> action(CQG))} |
{last, list(CQG)} |
no_more.
-spec stop() -> action(any()).
stop() ->
stop.
-spec do_unfold(CQL, fun((CQL) -> step(CQM, CQL))) -> fun(() -> action(CQM)).
do_unfold(Initial, F) ->
fun() -> case F(Initial) of
{next, X, Acc} ->
{continue, X, do_unfold(Acc, F)};
done ->
stop
end end.
-spec unfold(CQQ, fun((CQQ) -> step(CQR, CQQ))) -> iterator(CQR).
unfold(Initial, F) ->
_pipe = Initial,
_pipe@1 = do_unfold(_pipe, F),
{iterator, _pipe@1}.
-spec repeatedly(fun(() -> CQV)) -> iterator(CQV).
repeatedly(F) ->
unfold(nil, fun(_) -> {next, F(), nil} end).
-spec repeat(CQX) -> iterator(CQX).
repeat(X) ->
repeatedly(fun() -> X end).
-spec from_list(list(CQZ)) -> iterator(CQZ).
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(CRC)), fun((CRE, CRC) -> CRE), CRE) -> CRE.
do_fold(Continuation, F, Accumulator) ->
case Continuation() of
{continue, Elem, Next} ->
do_fold(Next, F, F(Accumulator, Elem));
stop ->
Accumulator
end.
-spec fold(iterator(CRF), CRH, fun((CRH, CRF) -> CRH)) -> CRH.
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(CRK)) -> list(CRK).
to_list(Iterator) ->
_pipe = Iterator,
_pipe@1 = fold(_pipe, [], fun(Acc, E) -> [E | Acc] end),
gleam@list:reverse(_pipe@1).
-spec step(iterator(CRN)) -> step(CRN, iterator(CRN)).
step(Iterator) ->
case (erlang:element(2, Iterator))() of
stop ->
done;
{continue, E, A} ->
{next, E, {iterator, A}}
end.
-spec do_take(fun(() -> action(CRS)), integer()) -> fun(() -> action(CRS)).
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(CRV), integer()) -> iterator(CRV).
take(Iterator, Desired) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_take(_pipe, Desired),
{iterator, _pipe@1}.
-spec do_drop(fun(() -> action(CRY)), integer()) -> action(CRY).
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(CSB), integer()) -> iterator(CSB).
drop(Iterator, Desired) ->
_pipe = fun() -> do_drop(erlang:element(2, Iterator), Desired) end,
{iterator, _pipe}.
-spec do_map(fun(() -> action(CSE)), fun((CSE) -> CSG)) -> fun(() -> action(CSG)).
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(CSI), fun((CSI) -> CSK)) -> iterator(CSK).
map(Iterator, F) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_map(_pipe, F),
{iterator, _pipe@1}.
-spec do_append(fun(() -> action(CSM)), fun(() -> action(CSM))) -> action(CSM).
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(CSQ), iterator(CSQ)) -> iterator(CSQ).
append(First, Second) ->
_pipe = fun() ->
do_append(erlang:element(2, First), erlang:element(2, Second))
end,
{iterator, _pipe}.
-spec do_flatten(fun(() -> action(iterator(CSU)))) -> action(CSU).
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(CSY))) -> iterator(CSY).
flatten(Iterator) ->
_pipe = fun() -> do_flatten(erlang:element(2, Iterator)) end,
{iterator, _pipe}.
-spec flat_map(iterator(CTC), fun((CTC) -> iterator(CTE))) -> iterator(CTE).
flat_map(Iterator, F) ->
_pipe = Iterator,
_pipe@1 = map(_pipe, F),
flatten(_pipe@1).
-spec do_filter(fun(() -> action(CTH)), fun((CTH) -> boolean())) -> action(CTH).
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(CTK), fun((CTK) -> boolean())) -> iterator(CTK).
filter(Iterator, Predicate) ->
_pipe = fun() -> do_filter(erlang:element(2, Iterator), Predicate) end,
{iterator, _pipe}.
-spec cycle(iterator(CTN)) -> iterator(CTN).
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(CTR)), fun((CTR) -> boolean())) -> {ok, CTR} |
{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(CTV), fun((CTV) -> boolean())) -> {ok, CTV} | {error, nil}.
find(Haystack, Is_desired) ->
_pipe = erlang:element(2, Haystack),
do_find(_pipe, Is_desired).
-spec do_index(fun(() -> action(CTZ)), integer()) -> fun(() -> action({integer(),
CTZ})).
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(CUC)) -> iterator({integer(), CUC}).
index(Iterator) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_index(_pipe, 0),
{iterator, _pipe@1}.
-spec iterate(CUF, fun((CUF) -> CUF)) -> iterator(CUF).
iterate(Initial, F) ->
unfold(Initial, fun(Element) -> {next, Element, F(Element)} end).
-spec do_take_while(fun(() -> action(CUH)), fun((CUH) -> boolean())) -> fun(() -> action(CUH)).
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(CUK), fun((CUK) -> boolean())) -> iterator(CUK).
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(CUN)), fun((CUN) -> boolean())) -> action(CUN).
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(CUQ), fun((CUQ) -> boolean())) -> iterator(CUQ).
drop_while(Iterator, Predicate) ->
_pipe = fun() -> do_drop_while(erlang:element(2, Iterator), Predicate) end,
{iterator, _pipe}.
-spec do_scan(fun(() -> action(CUT)), fun((CUV, CUT) -> CUV), CUV) -> fun(() -> action(CUV)).
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(CUX), CUZ, fun((CUZ, CUX) -> CUZ)) -> iterator(CUZ).
scan(Iterator, Initial, F) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_scan(_pipe, F, Initial),
{iterator, _pipe@1}.
-spec do_zip(fun(() -> action(CVB)), fun(() -> action(CVD))) -> fun(() -> action({CVB,
CVD})).
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(CVG), iterator(CVI)) -> iterator({CVG, CVI}).
zip(Left, Right) ->
_pipe = do_zip(erlang:element(2, Left), erlang:element(2, Right)),
{iterator, _pipe}.
-spec next_chunk(fun(() -> action(CVO)), fun((CVO) -> CVQ), CVQ, list(CVO)) -> chunk(CVO, CVQ).
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(CVU)), fun((CVU) -> CVW), CVW, CVU) -> action(list(CVU)).
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(CVZ), fun((CVZ) -> any())) -> iterator(list(CVZ)).
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(CWH)), integer(), list(CWH)) -> sized_chunk(CWH).
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(CWL)), integer()) -> fun(() -> action(list(CWL))).
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(CWP), integer()) -> iterator(list(CWP)).
sized_chunk(Iterator, Count) ->
_pipe = erlang:element(2, Iterator),
_pipe@1 = do_sized_chunk(_pipe, Count),
{iterator, _pipe@1}.
-spec do_intersperse(fun(() -> action(CWT)), CWT) -> action(CWT).
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(CWW), CWW) -> iterator(CWW).
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(CWZ)), fun((CWZ) -> 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(CXB), fun((CXB) -> boolean())) -> boolean().
any(Iterator, Predicate) ->
_pipe = erlang:element(2, Iterator),
do_any(_pipe, Predicate).
-spec do_all(fun(() -> action(CXD)), fun((CXD) -> 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(CXF), fun((CXF) -> boolean())) -> boolean().
all(Iterator, Predicate) ->
_pipe = erlang:element(2, Iterator),
do_all(_pipe, Predicate).
-spec update_group_with(CXH) -> fun((gleam@option:option(list(CXH))) -> list(CXH)).
update_group_with(El) ->
fun(Maybe_group) -> case Maybe_group of
{some, Group} ->
[El | Group];
none ->
[El]
end end.
-spec group_updater(fun((CXL) -> CXM)) -> fun((gleam@map:map_(CXM, list(CXL)), CXL) -> gleam@map:map_(CXM, list(CXL))).
group_updater(F) ->
fun(Groups, Elem) ->
_pipe = Groups,
gleam@map:update(_pipe, F(Elem), update_group_with(Elem))
end.
-spec group(iterator(CXT), fun((CXT) -> CXV)) -> gleam@map:map_(CXV, list(CXT)).
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(CXZ), fun((CXZ, CXZ) -> CXZ)) -> {ok, CXZ} | {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(CYD)) -> {ok, CYD} | {error, nil}.
last(Iterator) ->
_pipe = Iterator,
reduce(_pipe, fun(_, Elem) -> Elem end).
-spec empty() -> iterator(any()).
empty() ->
{iterator, fun stop/0}.
-spec once(fun(() -> CYJ)) -> iterator(CYJ).
once(F) ->
_pipe = fun() -> {continue, F(), fun stop/0} end,
{iterator, _pipe}.
-spec single(CYL) -> iterator(CYL).
single(Elem) ->
once(fun() -> Elem end).
-spec do_interleave(fun(() -> action(CYN)), fun(() -> action(CYN))) -> action(CYN).
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(CYR), iterator(CYR)) -> iterator(CYR).
interleave(Left, Right) ->
_pipe = fun() ->
do_interleave(erlang:element(2, Left), erlang:element(2, Right))
end,
{iterator, _pipe}.
-spec do_fold_until(
fun(() -> action(CYV)),
fun((CYX, CYV) -> gleam@list:continue_or_stop(CYX)),
CYX
) -> CYX.
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(CYZ),
CZB,
fun((CZB, CYZ) -> gleam@list:continue_or_stop(CZB))
) -> CZB.
fold_until(Iterator, Initial, F) ->
_pipe = erlang:element(2, Iterator),
do_fold_until(_pipe, F, Initial).
-spec do_try_fold(
fun(() -> action(CZD)),
fun((CZF, CZD) -> {ok, CZF} | {error, CZG}),
CZF
) -> {ok, CZF} | {error, CZG}.
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(CZL), CZN, fun((CZN, CZL) -> {ok, CZN} | {error, CZO})) -> {ok,
CZN} |
{error, CZO}.
try_fold(Iterator, Initial, F) ->
_pipe = erlang:element(2, Iterator),
do_try_fold(_pipe, F, Initial).
-spec first(iterator(CZT)) -> {ok, CZT} | {error, nil}.
first(Iterator) ->
case (erlang:element(2, Iterator))() of
stop ->
{error, nil};
{continue, E, _@1} ->
{ok, E}
end.
-spec at(iterator(CZX), integer()) -> {ok, CZX} | {error, nil}.
at(Iterator, Index) ->
_pipe = Iterator,
_pipe@1 = drop(_pipe, Index),
first(_pipe@1).