Implement circular array

src/basic/basic.h

@@ -694,6 +694,46 @@ ReverseIter<T> IterateInReverse(Slice<T> *slice) {
     return {slice->end() - 1, slice};
 }
 
+template <class T>
+struct CircularArray {
+    Allocator allocator;
+    T        *data;
+    int16_t   cap;
+    int16_t   write;
+    int16_t   buffer_is_full;
+};
+
+template <class T>
+CircularArray<T> MakeCircularArray(Allocator allocator, int size) {
+    CircularArray<T> arr = {allocator};
+    arr.data             = AllocArray(allocator, T, size);
+    arr.cap              = size;
+    return arr;
+}
+
+template <class T>
+void Add(CircularArray<T> *arr, T item) {
+    int idx    = arr->write;
+    arr->write = (arr->write + 1) % arr->cap;
+    if (arr->write == 0) arr->buffer_is_full = 1;
+    arr->data[idx] = item;
+}
+
+template <class T>
+T Get(CircularArray<T> *arr, int idx, T default_value) {
+    if (idx >= arr->cap) return default_value;
+    int i = arr->write - 1 - idx;
+    if (i < 0 && arr->buffer_is_full) {
+        i = arr->cap + i;
+    }
+
+    if (i >= 0 && i < arr->cap) {
+        return arr->data[i];
+    } else {
+        return default_value;
+    }
+}
+
 struct UTF32Result {
     uint32_t out_str;
     int64_t  advance;

src/text_editor/commands_window.cpp

@@ -260,6 +260,7 @@ void ReplaceDebugData() {
 
     String view_list = DebugViewList(scratch);
     Append(buffer, ToString16(scratch, view_list));
+    Append(buffer, L"\n");
 
     String window_list = DebugWindowList(scratch);
     Append(buffer, ToString16(scratch, window_list));