paradygmaty.txt

## OZ ##
example function 

declare
fun {Reverse L}
   case L
   of nil then nil
   [] X|Xs then {Append{Reverse Xs}|[X]}
   end
end
X = {Reverse [1 2 3 4 5 6]}
{Browse X}

declare
fun {FoldReverse L}
   {FoldL L fun {$ A B} B|A end nil} 
end

## SHEME ##
(cdr '(1 2 3)) => (2 3)
(car '(1 2 3)) => 1

lambda 
(define mymap
	(lambda (fun lista)
		(if (null? lista)
			()
			(cons	(fun (car lista))
				(mymap fun(cdr lista))
			)
		)
	)
)

(mymap (lambda (x) (+ 1 x)) '(0 2 4 6))


## HASKEL ## 

dotp :: Num a => [a] -> [a] -> a 
dotp a b  = sum (zipWith (*) a b)
 
main = print $ dotp [1, 3, -5] [4, -2, -1]

split :: [a] -> ([a], [a])
split myList = splitAt (((length myList) + 1) `div` 2) myList

## ERLANG##

-module(z1).
-export([pythag/1]).

pythag(D) ->
	[ 	{A, B, C} ||
	 	A <- lists:seq(1, D div 2),
		B <- lists:seq(1, A),
		C <- lists:seq(trunc(math:sqrt(A * A + B * B)), trunc(math:sqrt(A * A + B * B))),
		A + B + C == D,
		A * A + B * B == C * C
	].

## PROLOG ##

k(a, b). k(a, d). k(b, c). k(b, e). k(c, f). k(d, e). k(d, g). k(e, f). k(e, h). k(f, i). k(g, h). k(h, i).

is_path(X, Y) :- path(X, Y, []).

path(X, X, _).

path(X, Y, _) :- k(X, Y).

path(X,Y,Path) :- 	k(X, Z),
		  			\+ member(Z, Path),
		  			path(Z, Y, [X | Path]).

jednokrotnie(X,L1):- select(X,L1,L2), \+ (select(X,L2,_)).
dwukrotnie(X,L1):- select(X,L1,L2), jednokrotnie(X,L2).