Fractran: Difference between revisions

{{works with|Julia|1.9}}<syntaxhighlight lang="julia">

# FRACTRAN interpreter implemented in Julia as an iterable struct

struct Fractran

input::BigInt

fracs::Vector{Rational{BigInt}}

n::Int

end

function eval(ft::Fractran)

(Int(log2(i)) for i ∈ ft if ispow2(i))

end

function Base.show(io::IO, ft::Fractran)

join(io, Iterators.take(eval(ft), ft.n ), ' ')

end

eval(Meta.parse("[" * replace(s, "/" => "//", " " => ",") * "]"))

code"17/91 78/85 19/51 23/38 29/33 77/29 95/23 77/19 1/17 11/13 13/11 15/14 15/2 55/1",

25)

println("First 30 iterations of FRACTRAN program 'primes':\n2 ",

join(Iterators.take(primes, 30), ' '), "\n")

println("First $(primes.n) primes:")

@show primes;</syntaxhighlight>

<pre>First 30 iterations of FRACTRAN program 'primes':

2 15 825 725 1925 2275 425 390 330 290 770 910 170 156 132 116 308 364 68 4 30 225 12375 10875 28875 25375 67375 79625 14875 13650 2550

First 25 primes:

primes = 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97</pre>