state context works

include/state.h

@@ -9,10 +9,12 @@ inline T* _sm_var(sm_state* state, U name, T init)
 {
 	auto val = &state->current->user.data[name];
 	bool set = val->set;
+
 	val->set = true;
-	val->free = false;
+	
+
 	return ( ! set ) ?
-		_sm_init<T>(val, init) :
+		(val->free = false, _sm_init<T>(val, init)) :
 		_sm_get<T>(val);
 }
 template<uint64_t name, typename T>
@@ -43,3 +45,5 @@ inline sm_yield sm_continue() { return (sm_yield)_sm_noop; }
 
 #define SM_YIELD(v) do { state->current->pc = __LINE__; return (sm_yield)(v); case __LINE__:; } while(0)
 
+sm_state* sm_new();
+void sm_free(sm_state* state);

src/dev.h

@@ -4,6 +4,8 @@
 
 #ifdef __cplusplus
 #include <cstdio>
+#define restrict __restrict__
+
 [[noreturn]]
 #else
 #include <stdio.h>

src/frame.cpp

@@ -5,7 +5,6 @@
 #define BODY(T, U, nm) \
 template<> T* _sm_init<T>(_sm_user* frame, T init) \
 { \
-	printf("hi\n"); \
 	frame->free = false; \
 	frame-> nm = (U)init; \
 	return (T*)&frame-> nm; \

src/main.cpp

@@ -16,21 +16,32 @@ sm_yield sm_test(sm_state* state)
 	*d = 10.f;
 
 	SM_BEGIN;
-		SM_YIELD(sm_continue());
 		*a = 5;
 		SM_YIELD(sm_continue());
+		printf("a = %d\n", *a);
 		*a = 0;
+		SM_YIELD(sm_continue());
+		printf("a = %d\n", *a);
 	SM_END;
 }
 
 int main()
 {
 
+	auto state = sm_new();
+
+	sm_test(state);
+	sm_test(state);
+	sm_test(state);
+
+	sm_free(state);
+
+	/*
 	//TODO: `sm_state` creation/initialisation & freeing functions
 	//TODO: Test `sm_test`
 
 	_test hi = { 0, 0 };
 	auto _a = _sm_init(nullptr, hi);
-
+	*/
 	return 0;
 }

src/state.cpp

@@ -1,13 +1,64 @@
 #include <state.h>
 #include "dev.h"
 
-void _sm_pop_stack(sm_state* state)
+/// A generator that just returns `nullptr` (end). Used for yielding without calling in to another generator. 
+///
+/// NOTE: To avoid uselessly creating a stack frame for calls to this generator, its address is (TODO) directly compared to when switching into a deeper generator, and then skipped entirely.
+sm_yield _sm_noop(sm_state*) 
 {
-	TODO("Free the current stack frame in `state` and replace it with the previous one");
+	return (sm_yield)nullptr;
 }
 
-sm_yield _sm_noop(sm_state*)
+sm_state* sm_new()
 {
-	return (sm_yield)nullptr;
+	auto state = box<sm_state>();
+	state->current = box<_sm_frame, true>();
+	return state;
 }
 
+inline static void sm_free_user(_sm_user* data)
+{
+	if (data->free) {
+		free(data->_ptr);
+	}
+}
+
+inline static void _sm_free_page(_sm_user_page* page)
+{
+	for (int i=0;i<_SM_STACK_SIZE;i++) sm_free_user(&page->data[i]);
+}
+
+inline static void _sm_free_all_pages(_sm_user_page* page)
+{
+	while(page)
+	{
+		_sm_free_page(page);
+		auto old = page;
+		page = page->next;
+		free(old);
+	}
+}
+
+void sm_free(sm_state* state)
+{
+	_sm_frame* frame = unbox(state).current;
+
+	while(frame)
+	{
+		_sm_free_all_pages(frame->user.next);
+		_sm_free_page(&frame->user);
+
+		frame = unbox(frame).prev;
+	}
+}
+
+void _sm_pop_stack(sm_state* state)
+{
+	if(!state->current) return;
+
+	auto last = unbox(state->current);
+	state->current = last.prev;
+
+	_sm_free_all_pages(last.user.next);
+	_sm_free_page(&last.user);
+}