// Author: Simon-Pierre Boucher — contact@spboucher.ai
#include "core/autograd.h"

#include <cstdio>
#include <cstdlib>

namespace forge {

Tape& Tape::get() {
    static Tape tape;
    return tape;
}

void Tape::backward(const Var& loss) {
    if (loss.value().numel() != 1) {
        std::fprintf(stderr, "forge: backward() needs a scalar loss\n");
        std::abort();
    }
    loss.grad().fill_(1.0f);
    for (auto it = nodes_.rbegin(); it != nodes_.rend(); ++it) (*it)();
    clear();
}

} // namespace forge