From fd938a7c29ed20d8b6753be6907f731a735ad84c Mon Sep 17 00:00:00 2001
From: "S. Mahmudul Hasan" <mahmudulhasan947@gmail.com>
Date: Sat, 14 Oct 2023 18:01:59 -0400
Subject: [PATCH] WIP: added deque iterator

---
 include/pocketpy/collections.h |  1 -
 include/pocketpy/common.h      |  1 +
 include/pocketpy/iter.h        | 15 +++++++++++++++
 src/collections.cpp            | 35 ++++++++++++++++++++++------------
 src/iter.cpp                   | 15 +++++++++++++++
 src/pocketpy.cpp               |  1 +
 6 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/include/pocketpy/collections.h b/include/pocketpy/collections.h
index 7132e050..7920a899 100644
--- a/include/pocketpy/collections.h
+++ b/include/pocketpy/collections.h
@@ -6,7 +6,6 @@
 #include "str.h"
 #include "iter.h"
 #include "cffi.h"
-#include <deque>
 
 namespace pkpy
 {
diff --git a/include/pocketpy/common.h b/include/pocketpy/common.h
index 08fb1980..929f9c5e 100644
--- a/include/pocketpy/common.h
+++ b/include/pocketpy/common.h
@@ -21,6 +21,7 @@
 #include <type_traits>
 #include <random>
 #include <bitset>
+#include <deque>
 
 #define PK_VERSION				"1.2.4"
 
diff --git a/include/pocketpy/iter.h b/include/pocketpy/iter.h
index 262b40ec..34f24498 100644
--- a/include/pocketpy/iter.h
+++ b/include/pocketpy/iter.h
@@ -29,6 +29,21 @@ struct ArrayIter{
     static void _register(VM* vm, PyObject* mod, PyObject* type);
 };
 
+struct PyDequeIter{
+    // Iterator for the deque type
+    PY_CLASS(PyDequeIter, builtins, "_deque_iterator")
+    PyObject* ref;
+    std::deque<PyObject*>::iterator begin;
+    std::deque<PyObject*>::iterator end;
+    std::deque<PyObject*>::iterator current;
+
+    PyDequeIter(PyObject* ref, std::deque<PyObject*>::iterator begin, std::deque<PyObject*>::iterator end)
+        : ref(ref), begin(begin), end(end), current(begin) {}
+
+    void _gc_mark() const{ PK_OBJ_MARK(ref); }
+    static void _register(VM* vm, PyObject* mod, PyObject* type);
+};
+
 struct StringIter{
     PY_CLASS(StringIter, builtins, "_string_iterator")
     PyObject* ref;
diff --git a/src/collections.cpp b/src/collections.cpp
index 65282943..0062ad54 100644
--- a/src/collections.cpp
+++ b/src/collections.cpp
@@ -20,6 +20,21 @@ namespace pkpy
                      return VAR(self.dequeItems.size());
                  });
 
+        vm->bind(type, "__repr__(self) -> str",
+                 [](VM *vm, ArgsView args)
+                 {
+                     PyDeque &self = _CAST(PyDeque &, args[0]);
+                     std::stringstream ss = self.getRepr(vm);
+                     return VAR(ss.str());
+                 });
+
+        vm->bind(type, "__iter__(self) -> deque_iterator",
+                 [](VM *vm, ArgsView args)
+                 {
+                     PyDeque &self = _CAST(PyDeque &, args[0]);
+                     return vm->heap.gcnew<PyDequeIter>(PyDequeIter::_type(vm), args[0], self.dequeItems.begin(), self.dequeItems.end());
+                 });
+
         vm->bind(type, "append(self, item) -> None",
                  [](VM *vm, ArgsView args)
                  {
@@ -127,14 +142,6 @@ namespace pkpy
                      return vm->None;
                  });
 
-        vm->bind(type, "__repr__(self) -> str",
-                 [](VM *vm, ArgsView args)
-                 {
-                     PyDeque &self = _CAST(PyDeque &, args[0]);
-                     std::stringstream ss = self.getRepr(vm);
-                     return VAR(ss.str());
-                 });
-
         vm->bind(type, "pop(self) -> PyObject",
                  [](VM *vm, ArgsView args)
                  {
@@ -197,17 +204,21 @@ namespace pkpy
             });
     }
 
-    PyDeque::PyDeque(VM *vm, PyObject* iterable, PyObject* maxlen)
+    PyDeque::PyDeque(VM *vm, PyObject *iterable, PyObject *maxlen)
     {
-        if(maxlen!=vm->None){
+        if (maxlen != vm->None)
+        {
             this->maxlen = CAST(int, maxlen);
             this->bounded = true;
-        }else{
+        }
+        else
+        {
             this->bounded = false;
             this->maxlen = -1;
         }
 
-        if(iterable!=vm->None){
+        if (iterable != vm->None)
+        {
             auto _lock = vm->heap.gc_scope_lock();
             PyObject *it = vm->py_iter(iterable); // strong ref
             PyObject *obj = vm->py_next(it);
diff --git a/src/iter.cpp b/src/iter.cpp
index eabc4790..57fa918c 100644
--- a/src/iter.cpp
+++ b/src/iter.cpp
@@ -26,6 +26,21 @@ namespace pkpy{
         });
     }
 
+    void PyDequeIter::_register(VM* vm, PyObject* mod, PyObject* type){
+        // Iterator for the deque type
+        vm->_all_types[PK_OBJ_GET(Type, type)].subclass_enabled = false;
+        vm->bind_notimplemented_constructor<PyDequeIter>(type);
+
+        vm->bind__iter__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ return obj; });
+        vm->bind__next__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+            PyDequeIter& self = _CAST(PyDequeIter&, obj);
+            if(self.current == self.end) return vm->StopIteration;
+            PyObject* ret = *self.current;
+            ++self.current;
+            return ret;
+        });
+    }
+
     void StringIter::_register(VM* vm, PyObject* mod, PyObject* type){
         vm->_all_types[PK_OBJ_GET(Type, type)].subclass_enabled = false;
         vm->bind_notimplemented_constructor<StringIter>(type);
diff --git a/src/pocketpy.cpp b/src/pocketpy.cpp
index 086e5772..5a265906 100644
--- a/src/pocketpy.cpp
+++ b/src/pocketpy.cpp
@@ -1414,6 +1414,7 @@ void init_builtins(VM* _vm) {
 
     RangeIter::register_class(_vm, _vm->builtins);
     ArrayIter::register_class(_vm, _vm->builtins);
+    PyDequeIter::register_class(_vm, _vm->builtins);
     StringIter::register_class(_vm, _vm->builtins);
     Generator::register_class(_vm, _vm->builtins);
 }