pocketpy/src/iter.h
BLUELOVETH ab3605a661 ...
2023-04-18 07:10:24 +00:00

104 lines
2.4 KiB
C++

#pragma once
#include "ceval.h"
#include "frame.h"
namespace pkpy{
class RangeIter final: public BaseIter {
i64 current;
Range r; // copy by value, so we don't need to keep ref
public:
RangeIter(VM* vm, PyObject* ref) : BaseIter(vm) {
this->r = OBJ_GET(Range, ref);
this->current = r.start;
}
bool _has_next(){
return r.step > 0 ? current < r.stop : current > r.stop;
}
PyObject* next(){
if(!_has_next()) return nullptr;
current += r.step;
return VAR(current-r.step);
}
};
template <typename T>
class ArrayIter final: public BaseIter {
PyObject* ref;
T* array;
int index;
public:
ArrayIter(VM* vm, PyObject* ref) : BaseIter(vm), ref(ref) {
array = &OBJ_GET(T, ref);
index = 0;
}
PyObject* next() override{
if(index >= array->size()) return nullptr;
return array->operator[](index++);
}
void _gc_mark() const override {
OBJ_MARK(ref);
}
};
class StringIter final: public BaseIter {
PyObject* ref;
int index;
public:
StringIter(VM* vm, PyObject* ref) : BaseIter(vm), ref(ref), index(0) {}
PyObject* next() override{
// TODO: optimize this to use iterator
// operator[] is O(n) complexity
Str* str = &OBJ_GET(Str, ref);
if(index == str->u8_length()) return nullptr;
return VAR(str->u8_getitem(index++));
}
void _gc_mark() const override {
OBJ_MARK(ref);
}
};
inline PyObject* Generator::next(){
if(state == 2) return nullptr;
// reset frame._sp_base
frame._sp_base = frame._s->_sp;
frame._locals.a = frame._s->_sp;
// restore the context
for(PyObject* obj: s_backup) frame._s->push(obj);
s_backup.clear();
vm->callstack.push(std::move(frame));
PyObject* ret = vm->_run_top_frame();
if(ret == vm->_py_op_yield){
// backup the context
frame = std::move(vm->callstack.top());
PyObject* ret = frame._s->popx();
for(PyObject* obj: frame.stack_view()) s_backup.push_back(obj);
vm->_pop_frame();
state = 1;
return ret;
}else{
state = 2;
return nullptr;
}
}
inline void Generator::_gc_mark() const{
frame._gc_mark();
for(PyObject* obj: s_backup) OBJ_MARK(obj);
}
template<typename T>
void gc_mark(T& t) {
if constexpr(std::is_base_of_v<BaseIter, T>){
t._gc_mark();
}
}
} // namespace pkpy