///
/// Allocate and store unpacked UTF32
/// string on the heap.
///
internal static int AllocString(Script vm, string str)
{
int address = Heap.Alloc(vm, str.Length);
for (int i = 0; i < str.Length; i++)
{
vm.WriteWord((int)str[i], address + i);
}
return(address);
}
internal static Value Fill(Script vm)
{
int val = vm.Argument(1).AsInt;
var array = new ArrayInfo(vm, vm.Argument(0).AsInt);
for (int i = array.address; i < array.address + array.length; i++)
{
vm.WriteWord(val, i);
}
return(Value.Void);
}
internal static Value Pop(Script vm)
{
var array = new ArrayInfo(vm, vm.Argument(0).AsInt);
int element = vm.Argument(1).AsInt;
if (array.length <= 0)
{
vm.cpu.status = Cpu.Status.BAD_MEMORY_ACCESS;
return(new Value(-1));
}
vm.WriteWord(array.length - 1, array.address - 1);
return(new Value(vm.ReadWord(array.address + array.length - 1)));
}
///
/// Push element to the end of an array, reallocate the array
/// if it's full. If new memory is allocated the old array is
/// freed.
///
/// arg(0) : Address of the array
/// arg(1) : Element
///
/// Note that the address is passed by value, so Push returns
/// a pointer to the allocated array. In the future, It might
/// be better to pass a pointer to the array instead, so that
/// the reference can be updated.
///
internal static Value Push(Script vm)
{
var array = new ArrayInfo(vm, vm.Argument(0).AsInt);
int element = vm.Argument(1).AsInt;
if (array.length >= array.capacity)
{
// Double array capacity
int new_array = Heap.Alloc(vm, array.capacity * 2);
vm.MemCopy(array.address, new_array, array.capacity);
if (array.address >= vm.cpu.heap)
{
// Only free array if it's in dynamic memory
Heap.Free(vm, array.address);
}
array.address = new_array;
}
vm.WriteWord(element, array.address + array.length);
vm.WriteWord(array.length + 1, array.address - 1);
return(new Value(array.address));
}
static void WriteHeader(Script vm, int address, ref Arena arena)
{
vm.WriteWord(arena.length, address - 1);
vm.WriteWord(arena.size, address - 2);
vm.WriteWord((int)arena.state, address - 3);
}