// The constructor.
internal Wam()
{
_h = _hb = new Address(_heap, 0);
_a = new Area("A", 9);
_p = new Address(_code, 0);
_b = new Address(_stack, 0);
_b[0]
= new ChoicePoint(0, null, null, null, null, null, null, null);
_e = _b + 1;
_e[0] = new Environment(0, null, null);
_tr = new Address(_trail, 0);
}
internal void RetryMeElse(Address L)
{
ChoicePoint b_ = (ChoicePoint)_b._cell;
uint n = b_._n;
for (uint i = 1; i <= n; i++)
{
_a[i] = _b[i];
}
_e = b_._ce;
_cp = b_._cp;
b_._bp = L;
UnwindTrail(b_._tr._address, _tr._address);
_tr = b_._tr;
_h = b_._h;
_hb = _h;
}
internal void TrustMe()
{
ChoicePoint b_ = (ChoicePoint)_b._cell;
uint n = b_._n;
for (uint i = 1; i <= n; i++)
{
_a[i] = _b[i];
}
_e = b_._ce;
_cp = b_._cp;
UnwindTrail(b_._tr._address, _tr._address);
_tr = b_._tr;
_h = b_._h;
_b = b_._b;
_hb = ((ChoicePoint)_b._cell)._hb;
}
// Choice instructions. There are no indexing instructions,
// so try, retry, and trust are unimplemented.
internal void TryMeElse(Address L, uint n)
{
Address b;
if (Greater(_e, _b))
{
b = _e + 1 + ((Environment)_e._cell)._n;
}
else
{
b = _b + 1 + ((ChoicePoint)_b._cell)._n;
}
ChoicePoint b_ = new ChoicePoint(n, _e, _cp, _b, L, _tr, _h, _hb);
b._cell = b_;
for (uint i = 1; i <= n; i++)
{
b[i] = _a[i];
}
_b = b;
_hb = _h;
}