%%
  Ported from the String Lambdas in    Functional Javascript
  /
%%
  This work is licensed under the MIT License :
%%
  ( c ) 2007  
  Portions Copyright ( c ) 2006  
%% 
%% Permission is hereby granted, free of charge, to any person obtaining
%% a copy of this software and associated documentation files (the
  " Software " ) , to deal in the Software without restriction , including
%% without limitation the rights to use, copy, modify, merge, publish,
  distribute , sublicense , and/or sell copies of the Software , and to
  permit persons to whom the Software is furnished to do so , subject to
%% the following conditions:
%% 
%% The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software .
%% 
  THE SOFTWARE IS PROVIDED " AS IS " , WITHOUT WARRANTY OF ANY KIND ,
%% EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
%% MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
%% NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM , DAMAGES OR OTHER LIABILITY , WHETHER IN AN ACTION
%% OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
%% WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

-module(lib_misc).

%%
%% Exported Functions
%%
-export([split_n_each/2, split_into_n/2, join/2, compose/1, all_and/1, join/1]).

split_n_each(N, List) when length(List) < N -> [List];

split_n_each(N, List) ->
    split_n_each(N, List, []).

split_into_n(N, List) when length(List) < N -> split_n_each(1, List);
split_into_n(N, List) -> split_n_each(length(List) div N, List).

%% @spec compose([function()]) -> function()
%% @doc Composing by chaining backward.

compose([Fn]) -> Fn;
compose([Fn | FnRest]) ->
  fun(Args) ->
    apply(Fn, [apply(compose(FnRest), [Args])])
  end.

%% returns the boolean result after applying all predicates
%% to all the arguments.

all_and([]) -> true;
all_and([Pred]) ->
    fun(Args) ->
        apply(Pred, [Args])
    end;
all_and([Pred | PredTail]) ->
    fun(Args) ->
        case apply(Pred, [Args]) of
            true -> apply(all_and(PredTail), [Args]);
            false -> false
        end
    end.

%% join a list of strings to form a single string

join(L) -> joinX(L, []).
joinX([X], Acc) -> Acc ++ X;
joinX([X | T], Acc) -> joinX(T, Acc ++ X).                                                      
    
%%
%% Local Functions
%%

split_n_each(_, [], Acc) -> Acc;
split_n_each(N, List, Acc) when length(List) < N 
                          -> split_n_each(N, [], Acc ++ [List]);
split_n_each(N, List, Acc) ->
    {List1, List2} = lists:split(N, List),
    split_n_each(N, List2, Acc ++ [List1]).

%% join a list of strings to form a single string
%% each separated by a separator

join(List, Separator) ->
    string:substr(joinx(fun thing_to_list/1, List, Separator), 2).

thing_to_list(X) when is_integer(X) -> integer_to_list(X);
thing_to_list(X) when is_float(X)   -> float_to_list(X);
thing_to_list(X) when is_atom(X)    -> atom_to_list(X);
thing_to_list(X) when is_list(X)    -> X.	%Assumed to be a string

joinx(F, [Hd|Tail], Separator) ->
    Separator ++ F(Hd) ++ joinx(F, Tail, Separator);
joinx(F, [], _) when is_function(F, 1) -> [].













 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
 without limitation the rights to use, copy, modify, merge, publish,
 the following conditions:
 
 The above copyright notice and this permission notice shall be
 
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 Exported Functions

 @spec compose([function()]) -> function()
 @doc Composing by chaining backward.
 returns the boolean result after applying all predicates
 to all the arguments.
 join a list of strings to form a single string

 Local Functions

 join a list of strings to form a single string
 each separated by a separator
Assumed to be a string
  Ported from the String Lambdas in    Functional Javascript
  /
  This work is licensed under the MIT License :
  ( c ) 2007  
  Portions Copyright ( c ) 2006  
  " Software " ) , to deal in the Software without restriction , including
  distribute , sublicense , and/or sell copies of the Software , and to
  permit persons to whom the Software is furnished to do so , subject to
  included in all copies or substantial portions of the Software .
  THE SOFTWARE IS PROVIDED " AS IS " , WITHOUT WARRANTY OF ANY KIND ,
  LIABLE FOR ANY CLAIM , DAMAGES OR OTHER LIABILITY , WHETHER IN AN ACTION

-module(lib_misc).

-export([split_n_each/2, split_into_n/2, join/2, compose/1, all_and/1, join/1]).

split_n_each(N, List) when length(List) < N -> [List];

split_n_each(N, List) ->
    split_n_each(N, List, []).

split_into_n(N, List) when length(List) < N -> split_n_each(1, List);
split_into_n(N, List) -> split_n_each(length(List) div N, List).


compose([Fn]) -> Fn;
compose([Fn | FnRest]) ->
  fun(Args) ->
    apply(Fn, [apply(compose(FnRest), [Args])])
  end.


all_and([]) -> true;
all_and([Pred]) ->
    fun(Args) ->
        apply(Pred, [Args])
    end;
all_and([Pred | PredTail]) ->
    fun(Args) ->
        case apply(Pred, [Args]) of
            true -> apply(all_and(PredTail), [Args]);
            false -> false
        end
    end.


join(L) -> joinX(L, []).
joinX([X], Acc) -> Acc ++ X;
joinX([X | T], Acc) -> joinX(T, Acc ++ X).                                                      
    

split_n_each(_, [], Acc) -> Acc;
split_n_each(N, List, Acc) when length(List) < N 
                          -> split_n_each(N, [], Acc ++ [List]);
split_n_each(N, List, Acc) ->
    {List1, List2} = lists:split(N, List),
    split_n_each(N, List2, Acc ++ [List1]).


join(List, Separator) ->
    string:substr(joinx(fun thing_to_list/1, List, Separator), 2).

thing_to_list(X) when is_integer(X) -> integer_to_list(X);
thing_to_list(X) when is_float(X)   -> float_to_list(X);
thing_to_list(X) when is_atom(X)    -> atom_to_list(X);

joinx(F, [Hd|Tail], Separator) ->
    Separator ++ F(Hd) ++ joinx(F, Tail, Separator);
joinx(F, [], _) when is_function(F, 1) -> [].









