// Slicing a many-pointer `mp[lo..hi]` builds a correct `{ ptr = mp + lo,
// len = hi - lo }` slice — the caller supplies the bounds (a `[*]T` carries no
// length of its own). This makes a `List` (whose `items` is `[*]T`) iterable
// with a `for`-each over `items[0..len]`.
//
// Regression (issue 0159): a many-pointer base previously fell through the
// subslice emitter's `else` arm to an undefined slice (`LLVMGetUndef`), so the
// resulting `.len` was garbage and iterating it segfaulted.
#import "modules/std.sx";

main :: () -> i64 {
    a : [4]i64 = .[5, 6, 7, 8];

    // Slice a many-pointer with explicit bounds.
    mp : [*]i64 = xx @a[0];
    s := mp[1..4];                       // { &a[1], len 3 }
    print("mp[1..4]: len={} [{} {} {}]\n", s.len, s[0], s[1], s[2]);  // 3 [6 7 8]

    // The payoff: iterate a List with a for-each over items[0..len].
    xs : List(i64) = .{};
    xs.append(10); xs.append(20); xs.append(30);
    sum := 0;
    for xs.items[0..xs.len] (e) { sum = sum + e; }
    print("List for-each sum={}\n", sum);                            // 60
    return 0;
}