Fibonacci Code Golf

Question

Generate the Fibonacci sequence in the fewest amount of characters possible. Any language is OK, except for one that you define with one operator, f, which prints the Fibonacci numbers.

Starting point: 25 14 characters in Haskell:

f=0:1:zipWith(+)f(tail f)

f=0:scanl(+)1f

Answer 1

Language: C++ Compiler Errors
Characters: 205

#define t template <int n> struct 
#define u template <> struct f
t g { int v[0]; };
t f { enum { v = f<n-1>::v + f<n-2>::v }; g<v> x;};
u<1> { enum { v = 1 }; };
u<0> { enum { v = 0 }; };
int main() { f<10> x; }

Answer 2

Befunge-93

31 chars

Will output an infinite list of the Fibonacci numbers, from 0 upwards, separated by tabs (could be reduced to 29 chars by deleting 9, in the first row, at the expense of no whitespace between numbers).

Unfortunately, all the Befunge-93 interpreters I've tried seem to overflow after 65k, so the output is only correct until and including 46368 (which is F₂₄).

#v::1p1>01g:.\:01p+9,#
 >     ^

Confirmed to work (with caveat above) with the Befunge-93 interpreter in Javascript and the Visual Befunge Applet Full.

I'm proud to say this is a completely original work (i.e. I did not copy this code from anyone), and it's much shorter than the Befunge solution currently on Rosetta Code.

Answer 3

Brainfuck, 33 characters:

+.>+.[<[>+>+<<-]>.[<+>-]>[<+>-]<]

Answer 4

BrainF**k:

>+++++>+>+<[[>]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[>+>+<<-]>>[<<+>>-]<[<]>-]

That'll generate the first 5. To generate more, replace the 5 + at the beginning with more: eg:

>++++++++++++++++++++++>+>+<[[>]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[>+>+<<-]>>[<<+>>-]<[<]>-]

Answer 5

Not the shortest, but the fastest at the time of posting. :-)

float f(float n) {
    return (pow(1+sqrt(5.0))/2.0),n) - pow(1+sqrt(5.0))/2.0),n)/sqrt(n));
}

Answer 6

Lua - 49 chars

function f(n)return n<2 and n or f(n-1)+f(n-2)end