## martes, 14 de febrero de 2017

### LED is my new Hello World - Prolog time

As promised...here's my LED Numbers app written in Prolog...it took me a long time...a lot of research...a lot of headaches...so I hope you like it...still a complete Prolog newbie...so...no warranties at all -;)

LEDNumbers.pl

```number(0,[[' _  '],['| | '],['|_| ']]).
number(1,[['  '],['| '],['| ']]).
number(2,[[' _  '],[' _| '],['|_  ']]).
number(3,[['_  '],['_| '],['_| ']]).
number(4,[['    '],['|_| '],['  | ']]).
number(5,[[' _  '],['|_  '],[' _| ']]).
number(6,[[' _  '],['|_  '],['|_| ']]).
number(7,[['_   '],[' |  '],[' |  ']]).
number(8,[[' _  '],['|_| '],['|_| ']]).
number(9,[[' _  '],['|_| '],[' _| ']]).

digits(0,[]).
digits(X,[H|T]) :- (X/10 > 0 -> H1 is floor(X/10), H is X mod 10, digits(H1,T)), !.

accRev([],A,A).
accRev([H|T],A,R) :- accRev(T,[H|A],R).

getDigits(L,R) :- digits(L,Y), accRev(Y, [], R).

show_records([]).
show_records([A|B]) :-
print_records(A), nl,
show_records(B).

print_records([]).
print_records([A|B]) :-
format('~w',A),
print_records(B).

merge([L], L).
merge([H1,H2|T], R) :- maplist(append, H1, H2, H),
merge([H|T], R), !.

listnum([],[]).
listnum([H1|T1],[R|Y]) :- number(H1,R), listnum(T1,Y).

led(X) :- getDigits(X,Y), listnum(Y,Z), merge(Z,R), show_records(R).
```

Wanna see it in action? Me too -;)

Back to learning -;)

Greetings,

Blag.
Development Culture.