[Rio-pm] [Golf] Função drop Haskell

[Blabos de Blebe]

sub drop{$a=@_[0];$a=0if$a<0;@_>2?@_[$a.. em _]:substr$_[1],$a}

2010/2/3 Nilson Santos Figueiredo Jr. <acid06 em gmail.com>:
> Boa. Na verdade o seu tem 63
> Não sabia que $#$b era válido. Pra mim, nesses casos, sempre tinha que
> usar $#{$b}.
>
> -Nilson
>
> 2010/2/3 Fernando Oliveira <fernandocorrea em gmail.com>:
>> 64:
>>
>> sub drop{($a,$b)=@_;$a=0if$a<0;ref$b?@$b[$a..$#$b]:substr$b,$a}
>>
>> Just another Perl Hacker,
>> Fernando (SmokeMachine)
>> http://perl-e.org
>> Sent from Rio De Janeiro, RJ, Brazil
>>
>>
>> Em 3 de fevereiro de 2010 18:33, Nilson Santos Figueiredo Jr.
>> <acid06 em gmail.com> escreveu:
>>>
>>> Eu tenho certeza que vai dar pra alguém melhorar, ainda tá grande.
>>> Mas se eu ficar mais tempo aqui tentando... vou ter meus dias inteiros
>>> pra ficar brincando de Golf ao invés de ter um trabalho. ;-)
>>>
>>> -Nilson
>>>
>>> 2010/2/3 breno <breno em rio.pm.org>:
>>> > Nilson, o final deveria dizer "mas é igual à versão do Nilson". Como
>>> > eu fiz um monte de edições e contagens, acabou q foi enviado sem e eu
>>> > nao percebi. O crédito e a menor tacada ainda são seus :-)
>>> >
>>> > []s
>>> >
>>> > -b
>>> >
>>> > 2010/2/3 Nilson Santos Figueiredo Jr. <acid06 em gmail.com>:
>>> >> Breno,
>>> >>
>>> >> Essa que você mandou é exatamente igual a minha anterior, mas ao invés
>>> >> de $a,$b eu uso $n,$w.
>>> >> Tem 65 chars fora e 55 dentro. Eu estava contando tudo.
>>> >>
>>> >> Mas essa tem um problema que retorna undef em alguns casos. Aí o
>>> >> Mantovani que tem que falar se é certo ou não.
>>> >>
>>> >> -Nilson
>>> >>
>>> >> 2010/2/3 breno <breno em rio.pm.org>:
>>> >>> fernando, nao pode funcionar pra valores negativos, vai entender :-)
>>> >>>
>>> >>> acredito que assim funcione:
>>> >>>
>>> >>> sub drop{($a,$b)=@_;$a=0if$a<0;ref$b?@$b[$a..$#{$b}]:substr$b,$a}
>>> >>>
>>> >>> 55 chars (dentro da sub).
>>> >>>
>>> >>>
>>> >>>
>>> >>> 2010/2/3 Fernando Oliveira <fernandocorrea em gmail.com>:
>>> >>>> 54:
>>> >>>>
>>> >>>> sub drop{($a,$b)=@_;ref$b?@$b[$a..$#{$b}]:substr$b,$a}
>>> >>>>
>>> >>>> Just another Perl Hacker,
>>> >>>> Fernando (SmokeMachine)
>>> >>>> http://perl-e.org
>>> >>>>
>>> >>>>
>>> >>>>
>>> >>>> Em 3 de fevereiro de 2010 17:54, Nilson Santos Figueiredo Jr.
>>> >>>> <acid06 em gmail.com> escreveu:
>>> >>>>>
>>> >>>>> Pronto, 80 caracteres (sem strict).
>>> >>>>> Estou satisfeito, agora é com vocês:
>>> >>>>>
>>> >>>>> sub
>>> >>>>>
>>> >>>>> drop{($n,$w)=@_;$n=0if$n<0;ref$w?@$w[$n..$#{$w}]:$n>length$w?'':substr$w,$n}
>>> >>>>>
>>> >>>>> -Nilson
>>> >>>>>
>>> >>>>> 2010/2/3 Nilson Santos Figueiredo Jr. <acid06 em gmail.com>:
>>> >>>>> > Melhorando a minha solução anterior, 85 caracteres (83 tirando o
>>> >>>>> > my):
>>> >>>>> >
>>> >>>>> > sub drop{my($n,$w)=@_;$n=0
>>> >>>>> > if$n<0;ref$w?@$w[$n..$#{$w}]:$n>length$w?'':substr($w,$n)}
>>> >>>>> >
>>> >>>>> > -Nilson
>>> >>>>> >
>>> >>>>> > 2010/2/3 Nilson Santos Figueiredo Jr. <acid06 em gmail.com>:
>>> >>>>> >> Uma solução, warnings and strict compliant:
>>> >>>>> >>
>>> >>>>> >> sub drop {
>>> >>>>> >>    my ($n, $w) = @_;
>>> >>>>> >>    $n = 0 if $n < 0;
>>> >>>>> >>    return ( $n > length $w ? '' : substr($w,$n) ) if !ref $w;
>>> >>>>> >>    @$w[$n..$#{$w}];
>>> >>>>> >> }
>>> >>>>> >>
>>> >>>>> >> Se colocar tudo em uma linha:
>>> >>>>> >>
>>> >>>>> >> sub drop{my($n,$w)=@_;$n=0
>>> >>>>> >>
>>> >>>>> >> if$n<0;return($n>length$w?'':substr($w,$n))if!ref$w;@$w[$n..$#{$w}];}
>>> >>>>> >>
>>> >>>>> >> 96 caracteres. Deve dar pra melhorar bastante ainda. Se tirar o
>>> >>>>> >> "my"
>>> >>>>> >> pra deixar de ser strict compliant, cai pra 94.
>>> >>>>> >>
>>> >>>>> >> -Nilson
>>> >>>>> >>
>>> >>>>> >> 2010/2/3 Daniel de Oliveira Mantovani
>>> >>>>> >> <daniel.oliveira.mantovani em gmail.com>:
>>> >>>>> >>> Olá pessoal, o desafio envolve a função drop do Haskell:
>>> >>>>> >>>
>>> >>>>> >>> <haskell>
>>> >>>>> >>> ghci> myDrop 2 "foobar"
>>> >>>>> >>> "obar"
>>> >>>>> >>> ghci> myDrop 4 "foobar"
>>> >>>>> >>> "ar"
>>> >>>>> >>> ghci> myDrop 4 [1,2]
>>> >>>>> >>> []
>>> >>>>> >>> ghci> myDrop 0 [1,2]
>>> >>>>> >>> [1,2]
>>> >>>>> >>> ghci> myDrop 7 []
>>> >>>>> >>> []
>>> >>>>> >>> ghci> myDrop (-2) "foo"
>>> >>>>> >>> "foo"
>>> >>>>> >>> </haskell>
>>> >>>>> >>>
>>> >>>>> >>> Eu fiz em Perl, para ficar claro:
>>> >>>>> >>>
>>> >>>>> >>> <perl>
>>> >>>>> >>> sub drop {
>>> >>>>> >>>    my ( $n, $xs ) = @_;
>>> >>>>> >>>    if ( ref $_[1] ne 'ARRAY' ) {
>>> >>>>> >>>        $n <= 0 ? return $_[1] : return substr( $_[1], $n );
>>> >>>>> >>>    }
>>> >>>>> >>>    if ( $n <= 0 || !@_ ) {
>>> >>>>> >>>        return @{$xs};
>>> >>>>> >>>    }
>>> >>>>> >>>    else {
>>> >>>>> >>>        shift @{$xs};
>>> >>>>> >>>        drop( ( $n - 1 ), $xs );
>>> >>>>> >>>    }
>>> >>>>> >>> }
>>> >>>>> >>> </perl>
>>> >>>>> >>>
>>> >>>>> >>> Exemplos:
>>> >>>>> >>> mantovani em mantovani-desktop:~/Perl/Funcional$ perl -MHaskell -E
>>> >>>>> >>> 'say
>>> >>>>> >>> $_ for drop(3,[1,2,3,4,5,6])'
>>> >>>>> >>> 4
>>> >>>>> >>> 5
>>> >>>>> >>> 6
>>> >>>>> >>>
>>> >>>>> >>> mantovani em mantovani-desktop:~/Perl/Funcional$ perl -MHaskell -E
>>> >>>>> >>> 'say
>>> >>>>> >>> $_ for drop(1,"ofernandoagoragolf")'
>>> >>>>> >>> fernandoagoragolf
>>> >>>>> >>>
>>> >>>>> >>> mantovani em mantovani-desktop:~/Perl/Funcional$ perl -MHaskell -E
>>> >>>>> >>> 'say
>>> >>>>> >>> $_ for drop(2,["mantovani","garu","fernando","blabos"])'
>>> >>>>> >>> fernando
>>> >>>>> >>> blabos
>>> >>>>> >>>
>>> >>>>> >>> mantovani em mantovani-desktop:~/Perl/Funcional$ perl -MHaskell -E
>>> >>>>> >>> 'say
>>> >>>>> >>> $_ for drop(-1,["mantovani","garu","fernando","blabos"])'
>>> >>>>> >>> mantovani
>>> >>>>> >>> garu
>>> >>>>> >>> fernando
>>> >>>>> >>> blabos
>>> >>>>> >>>
>>> >>>>> >>> mantovani em mantovani-desktop:~/Perl/Funcional$ perl -MHaskell -E
>>> >>>>> >>> 'say
>>> >>>>> >>> $_ for drop(-1,"mantovani")'
>>> >>>>> >>> mantovani
>>> >>>>> >>>
>>> >>>>> >>> mantovani em mantovani-desktop:~/Perl/Funcional$ perl -MHaskell -E
>>> >>>>> >>> 'say
>>> >>>>> >>> $_ for drop(10,"mantovani")'
>>> >>>>> >>>
>>> >>>>> >>> --
>>> >>>>> >>> "If you’ve never written anything thoughtful, then you’ve never
>>> >>>>> >>> had
>>> >>>>> >>> any difficult, important, or interesting thoughts. That’s the
>>> >>>>> >>> secret:
>>> >>>>> >>> people who don’t write, are people who don’t think."
>>> >>>>> >>> _______________________________________________
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>>> >>>>> >>>
>>> >>>>> >>
>>> >>>>> >
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>>> >>>>
>>> >>>>
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