-module(buclambda). -export([ pipe/1 , compose/1 , curry/1 , curry/2 , curry/3 , curry/4 , f_curry/1 , f_curry/2 , f_curry/3 , f_curry/4 , rcurry/1 , rcurry/2 , rcurry/3 , rcurry/4 , f_rcurry/1 , f_rcurry/2 , f_rcurry/3 , f_rcurry/4 ]). % @doc % Performs left-to-right function composition. % % 
% {ok, F} = buclambda:pipe([
%   buclambda:f_curry(fun lists:filter/2, [fun(E) -> E > 10 end]),
%   fun erlang:length/1
% ]).
% F([8, 9, 10, 11, 12]).
% % => 2
%
% @end -spec pipe(Functions :: [function() | {function(), [term()]}]) -> {ok, function()} | error. pipe(Functions) -> case lists:all(buclambda:f_rcurry(fun erlang:is_function/2, [1]), Functions) of true -> {ok, fun(X) -> funcalls(lists:reverse(Functions), X) end}; false -> error end. funcalls([], X) -> X; funcalls([Function|Rest], X) -> erlang:apply(Function, [funcalls(Rest, X)]). % @doc % Performs right-to-left function composition. % % 
% {ok, F} = buclambda:compose([
%   fun erlang:length/1,
%   buclambda:f_curry(fun lists:filter/2, [fun(E) -> E > 10 end])
% ]).
% F([8, 9, 10, 11, 12]).
% % => 2
%
% @end -spec compose(Functions :: [function()]) -> {ok, function()} | error. compose(Functions) -> case lists:all(buclambda:f_rcurry(fun erlang:is_function/2, [1]), Functions) of true -> {ok, fun(X) -> funcalls(Functions, X) end}; false -> error end. % @doc % Returns a curried equivalent of the provided function. % % 
% buclambda:curry(fun lists:keystore/4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A0) -> fun(A1) -> fun(A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
% @end -spec curry(Fun :: function()) -> {ok, function()} | error. curry(Fun) when is_function(Fun) -> case get_fun_info(Fun) of {Module, Function, Arity} -> curry(Module, Function, Arity); {_Fun, _Arity} -> error % TODO: currify(Fun, Arity, Arity, lr) end. % @doc % Same as buclambda:curry/1 but fails with an exception on error % @end -spec f_curry(Fun :: function()) -> function(). f_curry(Fun) -> case curry(Fun) of {ok, F} -> F; Error -> error(Error) end. % @doc % Returns a curried equivalent of the provided function, with the specified deep or params. % % 
% buclambda:curry(fun lists:keystore/4, 4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A0) -> fun(A1) -> fun(A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
% buclambda:curry(fun lists:keystore/4, 3).
% % => {ok, #Fun<erl_eval.12.99386804>}
% % => fun(A0, A1) -> fun(A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end end.
%
% buclambda:curry(fun lists:keystore/4, 2).
% % =>{ok, #Fun<erl_eval.18.99386804>}
% % => fun(A0, A1, A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end.
%
% buclambda:curry(fun lists:keystore/4, 1).
% % => {ok, #Fun<erl_eval.4.99386804>}
% % => fun(A0, A1, A2, A3) -> lists:keystore(A0, A1, A2, A3) end.
%
% {ok, F} = buclambda:curry(fun lists:keyfind/3, [toto, 1]).
% F([{tata, 1}, {toto, 2}, {titi, 3}]).
% % => {toto, 2}
% F([{tata, 1}, {tutu, 2}, {titi, 3}]).
% % => false
%
% @end -spec curry(Fun :: function(), DeepOrArgs :: integer() | [term()]) -> {ok, function()} | error. curry(Fun, Deep) when is_integer(Deep) orelse is_list(Deep) -> case get_fun_info(Fun) of {Module, Function, Arity} -> curry(Module, Function, Arity, Deep); {_Fun, _Arity} -> error % TODO: case bucs:type(Deep) of % TODO: integer -> % TODO: currify(Fun, Arity, Deep, lr); % TODO: _ -> % TODO: case currify(Fun, Arity, Arity - length(Deep) + 1, lr) of % TODO: {ok, CurryFun} -> {ok, erlang:apply(CurryFun, Deep)}; % TODO: Other -> Other % TODO: end % TODO: end end. % @doc % Same as buclambda:curry/2 but fails with an exception on error % @end -spec f_curry(Fun :: function(), DeepOrArgs :: integer() | [term()]) -> function(). f_curry(Fun, Deep) -> case curry(Fun, Deep) of {ok, F} -> F; Error -> error(Error) end. % @doc % Returns a reverse curried equivalent of the provided function. % % 
% buclambda:rcurry(fun lists:keystore/4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A3) -> fun(A2) -> fun(A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
-spec rcurry(Fun :: function()) -> {ok, function()} | error. rcurry(Fun) when is_function(Fun) -> case get_fun_info(Fun) of {Module, Function, Arity} -> rcurry(Module, Function, Arity); {_Fun, _Arity} -> error % TODO: currify(Fun, Arity, Arity, rl) end. % @doc % Same as buclambda:r_curry/1 but fails with an exception on error % @end -spec f_rcurry(Fun :: function()) -> function(). f_rcurry(Fun) -> case rcurry(Fun) of {ok, F} -> F; Error -> error(Error) end. % @doc % Returns a reverse curried equivalent of the provided function, with the specified deep or params. % % 
% buclambda:rcurry(fun lists:keystore/4, 4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A3) -> fun(A2) -> fun(A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
% buclambda:rcurry(fun lists:keystore/4, 3).
% % => {ok, #Fun<erl_eval.12.99386804>}
% % => fun(A3, A2) -> fun(A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end end.
%
% buclambda:rcurry(fun lists:keystore/4, 2).
% % => {ok, #Fun<erl_eval.18.99386804>}
% % => fun(A3, A2, A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end.
%
% buclambda:rcurry(fun lists:keystore/4, 1).
% % => {ok, #Fun<erl_eval.4.99386804>}
% % => fun(A3, A2, A1, A0) -> lists:keystore(A0, A1, A2, A3) end.
%
% {ok, F} = buclambda:rcurry(lists, keyfind, 3, [[{tata, 1}, {toto, 2}, {titi, 3}], 1]).
% F(toto).
% % => {toto, 2}
% F(tutu).
% % => false
%
% @end -spec rcurry(Fun :: function(), DeepOrArgs :: integer() | [term()]) -> {ok, function()} | error. rcurry(Fun, Deep) when is_integer(Deep) orelse is_list(Deep) -> case get_fun_info(Fun) of {Module, Function, Arity} -> rcurry(Module, Function, Arity, Deep); {_Fun, _Arity} -> error % TODO: case bucs:type(Deep) of % TODO: integer -> % TODO: currify(Fun, Arity, Deep, lr); % TODO: _ -> % TODO: case currify(Fun, Arity, Arity - length(Deep) + 1, rl) of % TODO: {ok, CurryFun} -> {ok, erlang:apply(CurryFun, Deep)}; % TODO: Other -> Other % TODO: end % TODO: end end. % @doc % Same as buclambda:rcurry/2 but fails with an exception on error % @end -spec f_rcurry(Fun :: function(), DeepOrArgs :: integer() | [term()]) -> function(). f_rcurry(Fun, Deep) -> case rcurry(Fun, Deep) of {ok, F} -> F; Error -> error(Error) end. % @doc % Returns a curried equivalent of the provided function. % % 
% buclambda:curry(lists, keystore, 4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A0) -> fun(A1) -> fun(A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
% @end -spec curry(Module :: module(), Function :: atom(), Arity :: integer()) -> {ok, function()} | error. curry(Module, Function, Arity) -> currify({Module, Function}, Arity, Arity, lr). % @doc % Same as buclambda:curry/3 but fails with an exception on error % @end -spec f_curry(Module :: module(), Function :: atom(), Arity :: integer()) -> function(). f_curry(Module, Function, Arity) -> case curry(Module, Function, Arity) of {ok, F} -> F; Error -> error(Error) end. % @doc % Returns a curried equivalent of the provided function, with the specified deep or params. % % 
% buclambda:curry(lists, keystore, 4, 4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A0) -> fun(A1) -> fun(A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
% buclambda:curry(lists, keystore, 4, 3).
% % => {ok, #Fun<erl_eval.12.99386804>}
% % => fun(A0, A1) -> fun(A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end end.
%
% buclambda:curry(lists, keystore, 4, 2).
% % =>{ok, #Fun<erl_eval.18.99386804>}
% % => fun(A0, A1, A2) -> fun(A3) -> lists:keystore(A0, A1, A2, A3) end end.
%
% buclambda:curry(lists, keystore, 4, 1).
% % => {ok, #Fun<erl_eval.4.99386804>}
% % => fun(A0, A1, A2, A3) -> lists:keystore(A0, A1, A2, A3) end.
%
% {ok, F} = buclambda:curry(lists, keyfind, 3, [toto, 1]).
% F([{tata, 1}, {toto, 2}, {titi, 3}]).
% % => {toto, 2}
% F([{tata, 1}, {tutu, 2}, {titi, 3}]).
% % => false
%
% @end -spec curry(Module :: module(), Function :: atom(), Arity :: integer(), DeepOrArgs :: integer() | [term()]) -> {ok, function()} | error. curry(Module, Function, Arity, Deep) when is_integer(Deep) -> currify({Module, Function}, Arity, Deep, lr); curry(Module, Function, Arity, Args) when is_list(Args) -> case curry(Module, Function, Arity, Arity - length(Args) + 1) of {ok, Fun} -> {ok, erlang:apply(Fun, Args)}; Other -> Other end. % @doc % Same as buclambda:curry/4 but fails with an exception on error % @end -spec f_curry(Module :: module(), Function :: atom(), Arity :: integer(), DeepOrArgs :: integer() | [term()]) -> function(). f_curry(Module, Function, Arity, Deep) -> case curry(Module, Function, Arity, Deep) of {ok, F} -> F; Error -> error(Error) end. % @doc % Returns a reverse curried equivalent of the provided function. % % 
% buclambda:rcurry(lists, keystore, 4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A3) -> fun(A2) -> fun(A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
% @end -spec rcurry(Module :: module(), Function :: atom(), Arity :: integer()) -> {ok, function()} | error. rcurry(Module, Function, Arity) -> currify({Module, Function}, Arity, Arity, rl). % @doc % Same as buclambda:rcurry/3 but fails with an exception on error % @end -spec f_rcurry(Module :: module(), Function :: atom(), Arity :: integer()) -> function(). f_rcurry(Module, Function, Arity) -> case rcurry(Module, Function, Arity) of {ok, F} -> F; Error -> error(Error) end. % @doc % Returns a reverse curried equivalent of the provided function, with the specified deep or params. % % 
% buclambda:rcurry(lists, keystore, 4, 4).
% % => {ok, #Fun<erl_eval.6.99386804>}
% % => fun(A3) -> fun(A2) -> fun(A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end end end.
%
% buclambda:rcurry(lists, keystore, 4, 3).
% % => {ok, #Fun<erl_eval.12.99386804>}
% % => fun(A3, A2) -> fun(A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end end.
%
% buclambda:rcurry(lists, keystore, 4, 2).
% % => {ok, #Fun<erl_eval.18.99386804>}
% % => fun(A3, A2, A1) -> fun(A0) -> lists:keystore(A0, A1, A2, A3) end end.
%
% buclambda:rcurry(lists, keystore, 4, 1).
% % => {ok, #Fun<erl_eval.4.99386804>}
% % => fun(A3, A2, A1, A0) -> lists:keystore(A0, A1, A2, A3) end.
%
% {ok, F} = buclambda:rcurry(lists, keyfind, 3, [[{tata, 1}, {toto, 2}, {titi, 3}], 1]).
% F(toto).
% % => {toto, 2}
% F(tutu).
% % => false
%
% @end -spec rcurry(Module :: module(), Function :: atom(), Arity :: integer(), DeepOrArgs :: integer() | [term()]) -> {ok, function()} | error. rcurry(Module, Function, Arity, Deep) when is_integer(Deep) -> currify({Module, Function}, Arity, Deep, rl); rcurry(Module, Function, Arity, Args) when is_list(Args) -> case rcurry(Module, Function, Arity, Arity - length(Args) + 1) of {ok, Fun} -> {ok, erlang:apply(Fun, Args)}; Other -> Other end. % @doc % Same as buclambda:rcurry/4 but fails with an exception on error % @end -spec f_rcurry(Module :: module(), Function :: atom(), Arity :: integer(), DeepOrArgs :: integer() | [term()]) -> function(). f_rcurry(Module, Function, Arity, Deep) -> case rcurry(Module, Function, Arity, Deep) of {ok, F} -> F; Error -> error(Error) end. % ----------------------------------------------------------------------------- currify(Function, Arity, Deep, Orient) when ((is_tuple(Function) andalso size(Function) == 2 andalso is_atom(element(1, Function)) andalso is_atom(element(1, Function))) orelse is_function(Function, Arity)), is_integer(Arity), is_integer(Deep), Deep =< Arity, (Orient == lr orelse Orient == rl) -> FunStr = lists:flatten([currify(Function, Arity, Deep, Deep, Orient), "."]), io:format("% => ~s~n% => ", [FunStr]), case erl_scan:string(FunStr) of {ok, Scanned, _} -> case erl_parse:parse_exprs(Scanned) of {ok, Parsed} -> case erl_eval:exprs(Parsed, []) of {value, Fun, _Env} -> {ok, Fun}; _ -> error end; _Error -> error end; _Error -> error end; currify(_Function, _Arity, _Deep, _Orient) -> error. currify({Module, Function}, Arity, _Deep, 0, _Orient) -> io_lib:format("~p:~p(~s)", [Module, Function, string:join(args(0, Arity, 1), ", ")]); % TODO: currify(Function, Arity, _Deep, 0, _Orient) when is_function(Function) -> % TODO: io_lib:format("(~s)(~s)", [fun_to_string(Function), string:join(args(0, Arity, 1), ", ")]); currify(Function, Arity, Deep, N, lr) when N == Deep -> NB = Arity - (Deep - 1), io_lib:format("fun(~s) -> ~s end", [string:join(args(0, NB, 1), ", "), currify(Function, Arity, Deep, N - 1, lr)]); currify(Function, Arity, Deep, N, lr) -> io_lib:format("fun(A~p) -> ~s end", [(Deep - N + 1) + (Arity - (Deep + 1)), currify(Function, Arity, Deep, N - 1, lr)]); currify(Function, Arity, Deep, N, rl) when N == Deep -> NB = Arity - (Deep - 1), io_lib:format("fun(~s) -> ~s end", [string:join(args(Arity - 1, NB, -1), ", "), currify(Function, Arity, Deep, N - 1, rl)]); currify(Function, Arity, Deep, N, rl) -> io_lib:format("fun(A~p) -> ~s end", [N - 1, currify(Function, Arity, Deep, N - 1, rl)]). args(_Start, 0, _Add) -> []; args(Start, N, Add) -> [lists:flatten(io_lib:format("A~p", [Start]))|args(Start + Add, N - 1, Add)]. get_fun_info(Fun) -> Infos = erlang:fun_info(Fun), {module, Module} = lists:keyfind(module, 1, Infos), {name, Function} = lists:keyfind(name, 1, Infos), {arity, Arity} = lists:keyfind(arity, 1, Infos), case lists:member({Function, Arity}, Module:module_info(exports)) of true -> {Module, Function, Arity}; false -> {Fun, Arity} end. % TODO: fun_to_string(Fun) -> % TODO: {env, [{_, _, _, Abs}]} = erlang:fun_info(Fun, env), % TODO: lists:flatten(erl_pp:expr({'fun', 1, {clauses, Abs}})).