fib.flx

open syntax chips;

// the most basic integer summing device
chip sum
  connector pins
  pin i1: %< int
  pin i2: %< int
  pin r1: %> int
{
  while true do
    write(pins.r1,
	pins.i1.read + pins.i2.read
    );
  done
}

// the most basic integer duplicating device
chip dup
  connector pins
  pin i1 : %< int
  pin r1 : %> int
  pin r2 : %> int
{
  var n: int;
  while true do
    n = read(pins.i1);
    write(pins.r1, n);
    write(pins.r2, n);
  done
}

// the most basic integer printing device
// we artificially cap this at 40 iterations
chip display
  connector pins
  pin i1: %< int
{
  var n =0;
  while n <= 40 do
    println$ read(pins.i1);
    n = n + 1;
  done
}

// a chip to kick off the processing,
// it provides the initial values at the start
chip initializer
  connector pins
  pin fn0 : %> int
  pin fn1 : %> int
{
  write(pins.fn0, 0);
  write(pins.fn1, 1);
}


// create some copies of the stock duplicators
// because we need two of them
device dupFn = dup;
device dupFn1 = dup;

// connect everything together.
// believe it or not, this is the heart of the fibonacci
// this corresponds to the diagram above.
circuit
  connect dupFn.r1, display.i1
  connect dupFn.r2, sum.i1
  connect dupFn1.r1, sum.i2
  connect dupFn1.r2, dupFn.i1
  connect sum.r1, dupFn1.i1

  // introduce our initial values to the circuit
  connect initializer.fn0, dupFn.i1
  connect initializer.fn1, dupFn1.i1
endcircuit

output.txt

$ flx -c --static -o fib fib.flx
$ time ./fib
0
1
1
2
3
5
8
13
21
34
55
89
144
233
377
610
987
1597
2584
4181
6765
10946
17711
28657
46368
75025
121393
196418
317811
514229
832040
1346269
2178309
3524578
5702887
9227465
14930352
24157817
39088169
63245986
102334155

real	0m0.004s
user	0m0.002s
sys	0m0.001s