Your code will throw an error for the perfectly legitimate case:

array(array(int)) a = ({({0, 1})}); flatten(a+a);

/ Henrik Grubbström (Lysator)

Previous text:

2003-04-28 16:12: Subject: Array.flatten

---

In order to not escalate the CVS war, I'll present my solution for how to deal with cyclic arrays in Array.flatten here:

//! Flatten a multi-dimensional array to a one-dimensional array. //! @trows //! @[flatten] throws an error if @[a] is cyclic. array flatten(array a) { array ret=({}); multiset seen = (<>);

void low_flatten(array aa) { foreach(aa, mixed b) if(arrayp(b)) { if(!sizeof([array]b)) continue; if(seen[b]) error("Trying to flatten a cyclic array.\n"); seen[b]=1; low_flatten([array]b); } else ret += ({ b }); }; low_flatten(a); return ret; }

(aside from the fact the programs like the one below hangs pike)

void foo() {

void bar(array i) { error("gazonk\n"); };

array a = ({ 0 }); a[0]=a; bar(a); }

/ Martin Nilsson (har bott i google)

While the fix grubba made does not necessarily produce useful results for cyclic structures, it seemed like a decent solution IMHO.

/ Johan Sundström (folkskådare)

Previous text:

2003-04-28 16:12: Subject: Array.flatten

---

In order to not escalate the CVS war, I'll present my solution for how to deal with cyclic arrays in Array.flatten here:

//! Flatten a multi-dimensional array to a one-dimensional array. //! @trows //! @[flatten] throws an error if @[a] is cyclic. array flatten(array a) { array ret=({}); multiset seen = (<>);

void low_flatten(array aa) { foreach(aa, mixed b) if(arrayp(b)) { if(!sizeof([array]b)) continue; if(seen[b]) error("Trying to flatten a cyclic array.\n"); seen[b]=1; low_flatten([array]b); } else ret += ({ b }); }; low_flatten(a); return ret; }

(aside from the fact the programs like the one below hangs pike)

void foo() {

void bar(array i) { error("gazonk\n"); };

array a = ({ 0 }); a[0]=a; bar(a); }

/ Martin Nilsson (har bott i google)