7 files changed, 260 insertions, 126 deletions

diff --git a/src/nvim/api/buffer.c b/src/nvim/api/buffer.c
index a268e04559..8355bfe868 100644
--- a/src/nvim/api/buffer.c
+++ b/src/nvim/api/buffer.c
@@ -51,10 +51,10 @@ Integer buffer_get_length(Buffer buffer, Error *err)
 String buffer_get_line(Buffer buffer, Integer index, Error *err)
 {
   String rv = {.size = 0};
-  StringArray slice = buffer_get_slice(buffer, index, index, true, true, err);
+  Array slice = buffer_get_slice(buffer, index, index, true, true, err);
 
   if (!err->set && slice.size) {
-    rv = slice.items[0];
+    rv = slice.items[0].data.string;
   }
 
   free(slice.items);
@@ -70,7 +70,8 @@ String buffer_get_line(Buffer buffer, Integer index, Error *err)
 /// @param[out] err Details of an error that may have occurred
 void buffer_set_line(Buffer buffer, Integer index, String line, Error *err)
 {
-  StringArray array = {.items = &line, .size = 1};
+  Object l = STRING_OBJ(line);
+  Array array = {.items = &l, .size = 1};
   buffer_set_slice(buffer, index, index, true, true, array, err);
 }
 
@@ -81,7 +82,7 @@ void buffer_set_line(Buffer buffer, Integer index, String line, Error *err)
 /// @param[out] err Details of an error that may have occurred
 void buffer_del_line(Buffer buffer, Integer index, Error *err)
 {
-  StringArray array = ARRAY_DICT_INIT;
+  Array array = ARRAY_DICT_INIT;
   buffer_set_slice(buffer, index, index, true, true, array, err);
 }
 
@@ -94,14 +95,14 @@ void buffer_del_line(Buffer buffer, Integer index, Error *err)
 /// @param include_end True if the slice includes the `end` parameter
 /// @param[out] err Details of an error that may have occurred
 /// @return An array of lines
-StringArray buffer_get_slice(Buffer buffer,
-                             Integer start,
-                             Integer end,
-                             Boolean include_start,
-                             Boolean include_end,
-                             Error *err)
+ArrayOf(String) buffer_get_slice(Buffer buffer,
+                                 Integer start,
+                                 Integer end,
+                                 Boolean include_start,
+                                 Boolean include_end,
+                                 Error *err)
 {
-  StringArray rv = ARRAY_DICT_INIT;
+  Array rv = ARRAY_DICT_INIT;
   buf_T *buf = find_buffer_by_handle(buffer, err);
 
   if (!buf) {
@@ -118,7 +119,7 @@ StringArray buffer_get_slice(Buffer buffer,
   }
 
   rv.size = (size_t)(end - start);
-  rv.items = xcalloc(sizeof(String), rv.size);
+  rv.items = xcalloc(sizeof(Object), rv.size);
 
   for (size_t i = 0; i < rv.size; i++) {
     int64_t lnum = start + (int64_t)i;
@@ -129,13 +130,13 @@ StringArray buffer_get_slice(Buffer buffer,
     }
 
     const char *bufstr = (char *) ml_get_buf(buf, (linenr_T) lnum, false);
-    rv.items[i] = cstr_to_string(bufstr);
+    rv.items[i] = STRING_OBJ(cstr_to_string(bufstr));
   }
 
 end:
   if (err->set) {
     for (size_t i = 0; i < rv.size; i++) {
-      free(rv.items[i].data);
+      free(rv.items[i].data.string.data);
     }
 
     free(rv.items);
@@ -152,15 +153,15 @@ end:
 /// @param end The last line index
 /// @param include_start True if the slice includes the `start` parameter
 /// @param include_end True if the slice includes the `end` parameter
-/// @param lines An array of lines to use as replacement(A 0-length array
-///        will simply delete the line range)
+/// @param replacement An array of lines to use as replacement(A 0-length
+//         array will simply delete the line range)
 /// @param[out] err Details of an error that may have occurred
 void buffer_set_slice(Buffer buffer,
                       Integer start,
                       Integer end,
                       Boolean include_start,
                       Boolean include_end,
-                      StringArray replacement,
+                      ArrayOf(String) replacement,
                       Error *err)
 {
   buf_T *buf = find_buffer_by_handle(buffer, err);
@@ -184,10 +185,15 @@ void buffer_set_slice(Buffer buffer,
   size_t new_len = replacement.size;
   size_t old_len = (size_t)(end - start);
   ssize_t extra = 0;  // lines added to text, can be negative
-  char **lines = (new_len != 0) ? xmalloc(new_len * sizeof(char *)) : NULL;
+  char **lines = (new_len != 0) ? xcalloc(new_len, sizeof(char *)) : NULL;
 
   for (size_t i = 0; i < new_len; i++) {
-    String l = replacement.items[i];
+    if (replacement.items[i].type != kObjectTypeString) {
+      set_api_error("all items in the replacement array must be strings", err);
+      goto end;
+    }
+
+    String l = replacement.items[i].data.string;
     lines[i] = xmemdupz(l.data, l.size);
   }
 
@@ -430,7 +436,10 @@ Boolean buffer_is_valid(Buffer buffer)
 ///        to the end of the buffer.
 /// @param lines An array of lines
 /// @param[out] err Details of an error that may have occurred
-void buffer_insert(Buffer buffer, Integer lnum, StringArray lines, Error *err)
+void buffer_insert(Buffer buffer,
+                   Integer lnum,
+                   ArrayOf(String) lines,
+                   Error *err)
 {
   buffer_set_slice(buffer, lnum, lnum, false, true, lines, err);
 }
@@ -441,9 +450,9 @@ void buffer_insert(Buffer buffer, Integer lnum, StringArray lines, Error *err)
 /// @param name The mark's name
 /// @param[out] err Details of an error that may have occurred
 /// @return The (row, col) tuple
-Position buffer_get_mark(Buffer buffer, String name, Error *err)
+ArrayOf(Integer, 2) buffer_get_mark(Buffer buffer, String name, Error *err)
 {
-  Position rv = POSITION_INIT;
+  Array rv = ARRAY_DICT_INIT;
   buf_T *buf = find_buffer_by_handle(buffer, err);
 
   if (!buf) {
@@ -473,8 +482,9 @@ Position buffer_get_mark(Buffer buffer, String name, Error *err)
     return rv;
   }
 
-  rv.row = posp->lnum;
-  rv.col = posp->col;
+  ADD(rv, INTEGER_OBJ(posp->lnum));
+  ADD(rv, INTEGER_OBJ(posp->col));
+
   return rv;
 }
 
diff --git a/src/nvim/api/private/defs.h b/src/nvim/api/private/defs.h
index b049412014..2dd229ec5f 100644
--- a/src/nvim/api/private/defs.h
+++ b/src/nvim/api/private/defs.h
@@ -5,17 +5,15 @@
 #include <stdbool.h>
 #include <string.h>
 
-#define ARRAY_DICT_INIT {.size = 0, .items = NULL}
+#define ARRAY_DICT_INIT {.size = 0, .capacity = 0, .items = NULL}
 #define STRING_INIT {.data = NULL, .size = 0}
 #define OBJECT_INIT { .type = kObjectTypeNil }
-#define POSITION_INIT { .row = 0, .col = 0 }
 #define REMOTE_TYPE(type) typedef uint64_t type
 
-#define TYPED_ARRAY_OF(type)                                                  \
-  typedef struct {                                                            \
-    type *items;                                                              \
-    size_t size;                                                              \
-  } type##Array
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+  #define ArrayOf(...) Array
+  #define DictionaryOf(...) Dictionary
+#endif
 
 // Basic types
 typedef struct {
@@ -38,15 +36,6 @@ REMOTE_TYPE(Tabpage);
 
 typedef struct object Object;
 
-TYPED_ARRAY_OF(Buffer);
-TYPED_ARRAY_OF(Window);
-TYPED_ARRAY_OF(Tabpage);
-TYPED_ARRAY_OF(String);
-
-typedef struct {
-  Integer row, col;
-} Position;
-
 typedef struct {
   Object *items;
   size_t size, capacity;
@@ -60,40 +49,30 @@ typedef struct {
 } Dictionary;
 
 typedef enum {
+  kObjectTypeBuffer,
+  kObjectTypeWindow,
+  kObjectTypeTabpage,
   kObjectTypeNil,
   kObjectTypeBoolean,
   kObjectTypeInteger,
   kObjectTypeFloat,
   kObjectTypeString,
-  kObjectTypeBuffer,
-  kObjectTypeWindow,
-  kObjectTypeTabpage,
   kObjectTypeArray,
   kObjectTypeDictionary,
-  kObjectTypePosition,
-  kObjectTypeStringArray,
-  kObjectTypeBufferArray,
-  kObjectTypeWindowArray,
-  kObjectTypeTabpageArray,
 } ObjectType;
 
 struct object {
   ObjectType type;
   union {
+    Buffer buffer;
+    Window window;
+    Tabpage tabpage;
     Boolean boolean;
     Integer integer;
     Float floating;
     String string;
-    Buffer buffer;
-    Window window;
-    Tabpage tabpage;
     Array array;
     Dictionary dictionary;
-    Position position;
-    StringArray stringarray;
-    BufferArray bufferarray;
-    WindowArray windowarray;
-    TabpageArray tabpagearray;
   } data;
 };
 
diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index f6fb46e1d1..14a820aa1b 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -6,6 +6,7 @@
 #include "nvim/api/private/helpers.h"
 #include "nvim/api/private/defs.h"
 #include "nvim/api/private/handle.h"
+#include "nvim/os/provider.h"
 #include "nvim/ascii.h"
 #include "nvim/vim.h"
 #include "nvim/buffer.h"
@@ -449,6 +450,130 @@ bool object_to_vim(Object obj, typval_T *tv, Error *err)
   return true;
 }
 
+void api_free_string(String value)
+{
+  if (!value.data) {
+    return;
+  }
+
+  free(value.data);
+}
+
+void api_free_object(Object value)
+{
+  switch (value.type) {
+    case kObjectTypeNil:
+    case kObjectTypeBoolean:
+    case kObjectTypeInteger:
+    case kObjectTypeFloat:
+    case kObjectTypeBuffer:
+    case kObjectTypeWindow:
+    case kObjectTypeTabpage:
+      break;
+
+    case kObjectTypeString:
+      api_free_string(value.data.string);
+      break;
+
+    case kObjectTypeArray:
+      api_free_array(value.data.array);
+      break;
+
+    case kObjectTypeDictionary:
+      api_free_dictionary(value.data.dictionary);
+      break;
+
+    default:
+      abort();
+  }
+}
+
+void api_free_array(Array value)
+{
+  for (size_t i = 0; i < value.size; i++) {
+    api_free_object(value.items[i]);
+  }
+
+  free(value.items);
+}
+
+void api_free_dictionary(Dictionary value)
+{
+  for (size_t i = 0; i < value.size; i++) {
+    api_free_string(value.items[i].key);
+    api_free_object(value.items[i].value);
+  }
+
+  free(value.items);
+}
+
+Dictionary api_metadata(void)
+{
+  static Dictionary metadata = ARRAY_DICT_INIT;
+
+  if (!metadata.size) {
+    msgpack_rpc_init_function_metadata(&metadata);
+    init_type_metadata(&metadata);
+    provider_init_feature_metadata(&metadata);
+  }
+
+  return copy_object(DICTIONARY_OBJ(metadata)).data.dictionary;
+}
+
+static void init_type_metadata(Dictionary *metadata)
+{
+  Dictionary types = ARRAY_DICT_INIT;
+
+  Dictionary buffer_metadata = ARRAY_DICT_INIT;
+  PUT(buffer_metadata, "id", INTEGER_OBJ(kObjectTypeBuffer));
+
+  Dictionary window_metadata = ARRAY_DICT_INIT;
+  PUT(window_metadata, "id", INTEGER_OBJ(kObjectTypeWindow));
+
+  Dictionary tabpage_metadata = ARRAY_DICT_INIT;
+  PUT(tabpage_metadata, "id", INTEGER_OBJ(kObjectTypeTabpage));
+
+  PUT(types, "Buffer", DICTIONARY_OBJ(buffer_metadata));
+  PUT(types, "Window", DICTIONARY_OBJ(window_metadata));
+  PUT(types, "Tabpage", DICTIONARY_OBJ(tabpage_metadata));
+
+  PUT(*metadata, "types", DICTIONARY_OBJ(types));
+}
+
+/// Creates a deep clone of an object
+static Object copy_object(Object obj)
+{
+  switch (obj.type) {
+    case kObjectTypeNil:
+    case kObjectTypeBoolean:
+    case kObjectTypeInteger:
+    case kObjectTypeFloat:
+      return obj;
+
+    case kObjectTypeString:
+      return STRING_OBJ(cstr_to_string(obj.data.string.data));
+
+    case kObjectTypeArray: {
+      Array rv = ARRAY_DICT_INIT;
+      for (size_t i = 0; i < obj.data.array.size; i++) {
+        ADD(rv, copy_object(obj.data.array.items[i]));
+      }
+      return ARRAY_OBJ(rv);
+    }
+
+    case kObjectTypeDictionary: {
+      Dictionary rv = ARRAY_DICT_INIT;
+      for (size_t i = 0; i < obj.data.dictionary.size; i++) {
+        KeyValuePair item = obj.data.dictionary.items[i];
+        PUT(rv, item.key.data, copy_object(item.value));
+      }
+      return DICTIONARY_OBJ(rv);
+    }
+    default:
+      abort();
+  }
+}
+
 /// Recursion helper for the `vim_to_object`. This uses a pointer table
 /// to avoid infinite recursion due to cyclic references
 ///
diff --git a/src/nvim/api/private/helpers.h b/src/nvim/api/private/helpers.h
index f1b9dc3bc8..f3ecdaacc4 100644
--- a/src/nvim/api/private/helpers.h
+++ b/src/nvim/api/private/helpers.h
@@ -51,36 +51,11 @@
   .data.array = a                                                             \
   })
 
-#define STRINGARRAY_OBJ(a) ((Object) {                                        \
-  .type = kObjectTypeStringArray,                                             \
-  .data.stringarray = a                                                       \
-  })
-
-#define BUFFERARRAY_OBJ(a) ((Object) {                                        \
-  .type = kObjectTypeBufferArray,                                             \
-  .data.bufferarray = a                                                       \
-  })
-
-#define WINDOWARRAY_OBJ(a) ((Object) {                                        \
-  .type = kObjectTypeWindowArray,                                             \
-  .data.windowarray = a                                                       \
-  })
-
-#define TABPAGEARRAY_OBJ(a) ((Object) {                                       \
-  .type = kObjectTypeTabpageArray,                                            \
-  .data.tabpagearray = a                                                      \
-  })
-
 #define DICTIONARY_OBJ(d) ((Object) {                                         \
   .type = kObjectTypeDictionary,                                              \
   .data.dictionary = d                                                        \
   })
 
-#define POSITION_OBJ(p) ((Object) {                                           \
-  .type = kObjectTypePosition,                                                \
-  .data.position = p                                                          \
-  })
-
 #define NIL ((Object) {.type = kObjectTypeNil})
 
 #define PUT(dict, k, v)                                                       \
@@ -91,6 +66,25 @@
 #define ADD(array, item)                                                      \
   kv_push(Object, array, item)
 
+// Helpers used by the generated msgpack-rpc api wrappers
+#define api_init_boolean
+#define api_init_integer
+#define api_init_float
+#define api_init_string = STRING_INIT
+#define api_init_buffer
+#define api_init_window
+#define api_init_tabpage
+#define api_init_object = NIL
+#define api_init_array = ARRAY_DICT_INIT
+#define api_init_dictionary = ARRAY_DICT_INIT
+
+#define api_free_boolean(value)
+#define api_free_integer(value)
+#define api_free_float(value)
+#define api_free_buffer(value)
+#define api_free_window(value)
+#define api_free_tabpage(value)
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "api/private/helpers.h.generated.h"
 #endif
diff --git a/src/nvim/api/tabpage.c b/src/nvim/api/tabpage.c
index 535722c087..91020d6850 100644
--- a/src/nvim/api/tabpage.c
+++ b/src/nvim/api/tabpage.c
@@ -13,9 +13,9 @@
 /// @param tabpage The tabpage
 /// @param[out] err Details of an error that may have occurred
 /// @return The number of windows in `tabpage`
-WindowArray tabpage_get_windows(Tabpage tabpage, Error *err)
+ArrayOf(Window) tabpage_get_windows(Tabpage tabpage, Error *err)
 {
-  WindowArray rv = ARRAY_DICT_INIT;
+  Array rv = ARRAY_DICT_INIT;
   tabpage_T *tab = find_tab_by_handle(tabpage, err);
 
   if (!tab) {
@@ -32,14 +32,14 @@ WindowArray tabpage_get_windows(Tabpage tabpage, Error *err)
     rv.size++;
   }
 
-  rv.items = xmalloc(sizeof(Window) * rv.size);
+  rv.items = xmalloc(sizeof(Object) * rv.size);
   size_t i = 0;
 
   FOR_ALL_TAB_WINDOWS(tp, wp) {
     if (tp != tab) {
       break;
     }
-    rv.items[i++] = wp->handle;
+    rv.items[i++] = WINDOW_OBJ(wp->handle);
   }
 
   return rv;
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index a2c50b4c81..43f2aafdc8 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -149,9 +149,9 @@ Integer vim_strwidth(String str, Error *err)
 /// Returns a list of paths contained in 'runtimepath'
 ///
 /// @return The list of paths
-StringArray vim_list_runtime_paths(void)
+ArrayOf(String) vim_list_runtime_paths(void)
 {
-  StringArray rv = ARRAY_DICT_INIT;
+  Array rv = ARRAY_DICT_INIT;
   uint8_t *rtp = p_rtp;
 
   if (*rtp == NUL) {
@@ -168,19 +168,20 @@ StringArray vim_list_runtime_paths(void)
   }
 
   // Allocate memory for the copies
-  rv.items = xmalloc(sizeof(String) * rv.size);
+  rv.items = xmalloc(sizeof(Object) * rv.size);
   // reset the position
   rtp = p_rtp;
   // Start copying
   for (size_t i = 0; i < rv.size && *rtp != NUL; i++) {
-    rv.items[i].data = xmalloc(MAXPATHL);
+    rv.items[i].type = kObjectTypeString;
+    rv.items[i].data.string.data = xmalloc(MAXPATHL);
     // Copy the path from 'runtimepath' to rv.items[i]
     int length = copy_option_part(&rtp,
-                                 (char_u *)rv.items[i].data,
+                                 (char_u *)rv.items[i].data.string.data,
                                  MAXPATHL,
                                  ",");
     assert(length >= 0);
-    rv.items[i].size = (size_t)length;
+    rv.items[i].data.string.size = (size_t)length;
   }
 
   return rv;
@@ -307,12 +308,22 @@ void vim_err_write(String str)
   write_msg(str, true);
 }
 
+/// Higher level error reporting function that ensures all str contents
+/// are written by sending a trailing linefeed to `vim_wrr_write`
+///
+/// @param str The message
+void vim_report_error(String str)
+{
+  vim_err_write(str);
+  vim_err_write((String) {.data = "\n", .size = 1});
+}
+
 /// Gets the current list of buffer handles
 ///
 /// @return The number of buffers
-BufferArray vim_get_buffers(void)
+ArrayOf(Buffer) vim_get_buffers(void)
 {
-  BufferArray rv = ARRAY_DICT_INIT;
+  Array rv = ARRAY_DICT_INIT;
   buf_T *b = firstbuf;
 
   while (b) {
@@ -320,12 +331,12 @@ BufferArray vim_get_buffers(void)
     b = b->b_next;
   }
 
-  rv.items = xmalloc(sizeof(Buffer) * rv.size);
+  rv.items = xmalloc(sizeof(Object) * rv.size);
   size_t i = 0;
   b = firstbuf;
 
   while (b) {
-    rv.items[i++] = b->handle;
+    rv.items[i++] = BUFFER_OBJ(b->handle);
     b = b->b_next;
   }
 
@@ -370,9 +381,9 @@ void vim_set_current_buffer(Buffer buffer, Error *err)
 /// Gets the current list of window handles
 ///
 /// @return The number of windows
-WindowArray vim_get_windows(void)
+ArrayOf(Window) vim_get_windows(void)
 {
-  WindowArray rv = ARRAY_DICT_INIT;
+  Array rv = ARRAY_DICT_INIT;
   tabpage_T *tp;
   win_T *wp;
 
@@ -380,11 +391,11 @@ WindowArray vim_get_windows(void)
     rv.size++;
   }
 
-  rv.items = xmalloc(sizeof(Window) * rv.size);
+  rv.items = xmalloc(sizeof(Object) * rv.size);
   size_t i = 0;
 
   FOR_ALL_TAB_WINDOWS(tp, wp) {
-    rv.items[i++] = wp->handle;
+    rv.items[i++] = WINDOW_OBJ(wp->handle);
   }
 
   return rv;
@@ -426,9 +437,9 @@ void vim_set_current_window(Window window, Error *err)
 /// Gets the current list of tabpage handles
 ///
 /// @return The number of tab pages
-TabpageArray vim_get_tabpages(void)
+ArrayOf(Tabpage) vim_get_tabpages(void)
 {
-  TabpageArray rv = ARRAY_DICT_INIT;
+  Array rv = ARRAY_DICT_INIT;
   tabpage_T *tp = first_tabpage;
 
   while (tp) {
@@ -436,12 +447,12 @@ TabpageArray vim_get_tabpages(void)
     tp = tp->tp_next;
   }
 
-  rv.items = xmalloc(sizeof(Tabpage) * rv.size);
+  rv.items = xmalloc(sizeof(Object) * rv.size);
   size_t i = 0;
   tp = first_tabpage;
 
   while (tp) {
-    rv.items[i++] = tp->handle;
+    rv.items[i++] = TABPAGE_OBJ(tp->handle);
     tp = tp->tp_next;
   }
 
@@ -501,22 +512,33 @@ void vim_unsubscribe(uint64_t channel_id, String event)
   channel_unsubscribe(channel_id, e);
 }
 
-/// Registers the channel as the provider for `method`. This fails if
-/// a provider for `method` is already registered.
+/// Registers the channel as the provider for `feature`. This fails if
+/// a provider for `feature` is already provided by another channel.
 ///
 /// @param channel_id The channel id
-/// @param method The method name
+/// @param feature The feature name
 /// @param[out] err Details of an error that may have occurred
-void vim_register_provider(uint64_t channel_id, String method, Error *err)
+void vim_register_provider(uint64_t channel_id, String feature, Error *err)
 {
   char buf[METHOD_MAXLEN];
-  xstrlcpy(buf, method.data, sizeof(buf));
+  xstrlcpy(buf, feature.data, sizeof(buf));
 
   if (!provider_register(buf, channel_id)) {
-    set_api_error("Provider already registered", err);
+    set_api_error("Feature doesn't exist", err);
   }
 }
 
+Array vim_get_api_info(uint64_t channel_id)
+{
+  Array rv = ARRAY_DICT_INIT;
+
+  assert(channel_id <= INT64_MAX);
+  ADD(rv, INTEGER_OBJ((int64_t)channel_id));
+  ADD(rv, DICTIONARY_OBJ(api_metadata()));
+
+  return rv;
+}
+
 /// Writes a message to vim output or error buffer. The string is split
 /// and flushed after each newline. Incomplete lines are kept for writing
 /// later.
diff --git a/src/nvim/api/window.c b/src/nvim/api/window.c
index 1ab441bed3..dd256f2b6d 100644
--- a/src/nvim/api/window.c
+++ b/src/nvim/api/window.c
@@ -33,14 +33,14 @@ Buffer window_get_buffer(Window window, Error *err)
 /// @param window The window handle
 /// @param[out] err Details of an error that may have occurred
 /// @return the (row, col) tuple
-Position window_get_cursor(Window window, Error *err)
+ArrayOf(Integer, 2) window_get_cursor(Window window, Error *err)
 {
-  Position rv = POSITION_INIT;
+  Array rv = ARRAY_DICT_INIT;
   win_T *win = find_window_by_handle(window, err);
 
   if (win) {
-    rv.row = win->w_cursor.lnum;
-    rv.col = win->w_cursor.col;
+    ADD(rv, INTEGER_OBJ(win->w_cursor.lnum));
+    ADD(rv, INTEGER_OBJ(win->w_cursor.col));
   }
 
   return rv;
@@ -51,31 +51,35 @@ Position window_get_cursor(Window window, Error *err)
 /// @param window The window handle
 /// @param pos the (row, col) tuple representing the new position
 /// @param[out] err Details of an error that may have occurred
-void window_set_cursor(Window window, Position pos, Error *err)
+void window_set_cursor(Window window, ArrayOf(Integer, 2) pos, Error *err)
 {
   win_T *win = find_window_by_handle(window, err);
 
-  if (!win) {
+  if (pos.size != 2 || pos.items[0].type != kObjectTypeInteger ||
+      pos.items[1].type != kObjectTypeInteger) {
+    set_api_error("\"pos\" argument must be a [row, col] array", err);
     return;
   }
 
-  if (pos.row <= 0 || pos.row > win->w_buffer->b_ml.ml_line_count) {
-    set_api_error("cursor position outside buffer", err);
+  if (!win) {
     return;
   }
 
-  if (pos.row > LONG_MAX || pos.row < LONG_MIN) {
-    set_api_error("Row value outside range", err);
+  int64_t row = pos.items[0].data.integer;
+  int64_t col = pos.items[1].data.integer;
+
+  if (row <= 0 || row > win->w_buffer->b_ml.ml_line_count) {
+    set_api_error("cursor position outside buffer", err);
     return;
   }
 
-  if (pos.col > INT_MAX || pos.col < INT_MIN) {
+  if (col > MAXCOL || col < 0) {
     set_api_error("Column value outside range", err);
     return;
   }
 
-  win->w_cursor.lnum = (linenr_T)pos.row;
-  win->w_cursor.col = (colnr_T)pos.col;
+  win->w_cursor.lnum = (linenr_T)row;
+  win->w_cursor.col = (colnr_T)col;
   win->w_cursor.coladd = 0;
   // When column is out of range silently correct it.
   check_cursor_col_win(win);
@@ -243,14 +247,14 @@ void window_set_option(Window window, String name, Object value, Error *err)
 /// @param window The window handle
 /// @param[out] err Details of an error that may have occurred
 /// @return The (row, col) tuple with the window position
-Position window_get_position(Window window, Error *err)
+ArrayOf(Integer, 2) window_get_position(Window window, Error *err)
 {
-  Position rv = POSITION_INIT;
+  Array rv = ARRAY_DICT_INIT;
   win_T *win = find_window_by_handle(window, err);
 
   if (win) {
-    rv.col = win->w_wincol;
-    rv.row = win->w_winrow;
+    ADD(rv, INTEGER_OBJ(win->w_winrow));
+    ADD(rv, INTEGER_OBJ(win->w_wincol));
   }
 
   return rv;