refactor(api): move extmark API to its own file

17 files changed, 917 insertions, 894 deletions

diff --git a/src/nvim/api/buffer.c b/src/nvim/api/buffer.c
index 92fcb59b34..cbfb63581f 100644
--- a/src/nvim/api/buffer.c
+++ b/src/nvim/api/buffer.c
@@ -32,7 +32,6 @@
 #include "nvim/misc1.h"
 #include "nvim/move.h"
 #include "nvim/ops.h"
-#include "nvim/syntax.h"
 #include "nvim/undo.h"
 #include "nvim/vim.h"
 #include "nvim/window.h"
@@ -1238,702 +1237,6 @@ ArrayOf(Integer, 2) nvim_buf_get_mark(Buffer buffer, String name, Error *err)
   return rv;
 }
 
-static Array extmark_to_array(ExtmarkInfo extmark, bool id, bool add_dict)
-{
-  Array rv = ARRAY_DICT_INIT;
-  if (id) {
-    ADD(rv, INTEGER_OBJ((Integer)extmark.mark_id));
-  }
-  ADD(rv, INTEGER_OBJ(extmark.row));
-  ADD(rv, INTEGER_OBJ(extmark.col));
-
-  if (add_dict) {
-    Dictionary dict = ARRAY_DICT_INIT;
-
-    if (extmark.end_row >= 0) {
-      PUT(dict, "end_row", INTEGER_OBJ(extmark.end_row));
-      PUT(dict, "end_col", INTEGER_OBJ(extmark.end_col));
-    }
-
-    if (extmark.decor) {
-      Decoration *decor = extmark.decor;
-      if (decor->hl_id) {
-        String name = cstr_to_string((const char *)syn_id2name(decor->hl_id));
-        PUT(dict, "hl_group", STRING_OBJ(name));
-      }
-      if (kv_size(decor->virt_text)) {
-        Array chunks = ARRAY_DICT_INIT;
-        for (size_t i = 0; i < decor->virt_text.size; i++) {
-          Array chunk = ARRAY_DICT_INIT;
-          VirtTextChunk *vtc = &decor->virt_text.items[i];
-          ADD(chunk, STRING_OBJ(cstr_to_string(vtc->text)));
-          if (vtc->hl_id > 0) {
-            ADD(chunk,
-                STRING_OBJ(cstr_to_string((const char *)syn_id2name(vtc->hl_id))));
-          }
-          ADD(chunks, ARRAY_OBJ(chunk));
-        }
-        PUT(dict, "virt_text", ARRAY_OBJ(chunks));
-      }
-
-      PUT(dict, "priority", INTEGER_OBJ(decor->priority));
-    }
-
-    if (dict.size) {
-      ADD(rv, DICTIONARY_OBJ(dict));
-    }
-  }
-
-  return rv;
-}
-
-/// Gets the position (0-indexed) of an extmark.
-///
-/// @param buffer  Buffer handle, or 0 for current buffer
-/// @param ns_id  Namespace id from |nvim_create_namespace()|
-/// @param id  Extmark id
-/// @param opts  Optional parameters. Keys:
-///          - details: Whether to include the details dict
-/// @param[out] err   Error details, if any
-/// @return 0-indexed (row, col) tuple or empty list () if extmark id was
-/// absent
-ArrayOf(Integer) nvim_buf_get_extmark_by_id(Buffer buffer, Integer ns_id,
-                                            Integer id, Dictionary opts,
-                                            Error *err)
-  FUNC_API_SINCE(7)
-{
-  Array rv = ARRAY_DICT_INIT;
-
-  buf_T *buf = find_buffer_by_handle(buffer, err);
-
-  if (!buf) {
-    return rv;
-  }
-
-  if (!ns_initialized((uint64_t)ns_id)) {
-    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
-    return rv;
-  }
-
-  bool details = false;
-  for (size_t i = 0; i < opts.size; i++) {
-    String k = opts.items[i].key;
-    Object *v = &opts.items[i].value;
-    if (strequal("details", k.data)) {
-      if (v->type == kObjectTypeBoolean) {
-        details = v->data.boolean;
-      } else if (v->type == kObjectTypeInteger) {
-        details = v->data.integer;
-      } else {
-        api_set_error(err, kErrorTypeValidation, "details is not an boolean");
-        return rv;
-      }
-    } else {
-      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
-      return rv;
-    }
-  }
-
-
-  ExtmarkInfo extmark = extmark_from_id(buf, (uint64_t)ns_id, (uint64_t)id);
-  if (extmark.row < 0) {
-    return rv;
-  }
-  return extmark_to_array(extmark, false, details);
-}
-
-/// Gets extmarks in "traversal order" from a |charwise| region defined by
-/// buffer positions (inclusive, 0-indexed |api-indexing|).
-///
-/// Region can be given as (row,col) tuples, or valid extmark ids (whose
-/// positions define the bounds). 0 and -1 are understood as (0,0) and (-1,-1)
-/// respectively, thus the following are equivalent:
-///
-/// <pre>
-///   nvim_buf_get_extmarks(0, my_ns, 0, -1, {})
-///   nvim_buf_get_extmarks(0, my_ns, [0,0], [-1,-1], {})
-/// </pre>
-///
-/// If `end` is less than `start`, traversal works backwards. (Useful
-/// with `limit`, to get the first marks prior to a given position.)
-///
-/// Example:
-///
-/// <pre>
-///   local a   = vim.api
-///   local pos = a.nvim_win_get_cursor(0)
-///   local ns  = a.nvim_create_namespace('my-plugin')
-///   -- Create new extmark at line 1, column 1.
-///   local m1  = a.nvim_buf_set_extmark(0, ns, 0, 0, 0, {})
-///   -- Create new extmark at line 3, column 1.
-///   local m2  = a.nvim_buf_set_extmark(0, ns, 0, 2, 0, {})
-///   -- Get extmarks only from line 3.
-///   local ms  = a.nvim_buf_get_extmarks(0, ns, {2,0}, {2,0}, {})
-///   -- Get all marks in this buffer + namespace.
-///   local all = a.nvim_buf_get_extmarks(0, ns, 0, -1, {})
-///   print(vim.inspect(ms))
-/// </pre>
-///
-/// @param buffer  Buffer handle, or 0 for current buffer
-/// @param ns_id  Namespace id from |nvim_create_namespace()|
-/// @param start  Start of range: a 0-indexed (row, col) or valid extmark id
-/// (whose position defines the bound). |api-indexing|
-/// @param end  End of range (inclusive): a 0-indexed (row, col) or valid
-/// extmark id (whose position defines the bound). |api-indexing|
-/// @param opts  Optional parameters. Keys:
-///          - limit:  Maximum number of marks to return
-///          - details Whether to include the details dict
-/// @param[out] err   Error details, if any
-/// @return List of [extmark_id, row, col] tuples in "traversal order".
-Array nvim_buf_get_extmarks(Buffer buffer, Integer ns_id, Object start, Object end, Dictionary opts,
-                            Error *err)
-  FUNC_API_SINCE(7)
-{
-  Array rv = ARRAY_DICT_INIT;
-
-  buf_T *buf = find_buffer_by_handle(buffer, err);
-  if (!buf) {
-    return rv;
-  }
-
-  if (!ns_initialized((uint64_t)ns_id)) {
-    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
-    return rv;
-  }
-
-  Integer limit = -1;
-  bool details = false;
-
-  for (size_t i = 0; i < opts.size; i++) {
-    String k = opts.items[i].key;
-    Object *v = &opts.items[i].value;
-    if (strequal("limit", k.data)) {
-      if (v->type != kObjectTypeInteger) {
-        api_set_error(err, kErrorTypeValidation, "limit is not an integer");
-        return rv;
-      }
-      limit = v->data.integer;
-    } else if (strequal("details", k.data)) {
-      if (v->type == kObjectTypeBoolean) {
-        details = v->data.boolean;
-      } else if (v->type == kObjectTypeInteger) {
-        details = v->data.integer;
-      } else {
-        api_set_error(err, kErrorTypeValidation, "details is not an boolean");
-        return rv;
-      }
-    } else {
-      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
-      return rv;
-    }
-  }
-
-  if (limit == 0) {
-    return rv;
-  } else if (limit < 0) {
-    limit = INT64_MAX;
-  }
-
-
-  bool reverse = false;
-
-  int l_row;
-  colnr_T l_col;
-  if (!extmark_get_index_from_obj(buf, ns_id, start, &l_row, &l_col, err)) {
-    return rv;
-  }
-
-  int u_row;
-  colnr_T u_col;
-  if (!extmark_get_index_from_obj(buf, ns_id, end, &u_row, &u_col, err)) {
-    return rv;
-  }
-
-  if (l_row > u_row || (l_row == u_row && l_col > u_col)) {
-    reverse = true;
-  }
-
-
-  ExtmarkInfoArray marks = extmark_get(buf, (uint64_t)ns_id, l_row, l_col,
-                                       u_row, u_col, (int64_t)limit, reverse);
-
-  for (size_t i = 0; i < kv_size(marks); i++) {
-    ADD(rv, ARRAY_OBJ(extmark_to_array(kv_A(marks, i), true, (bool)details)));
-  }
-
-  kv_destroy(marks);
-  return rv;
-}
-
-/// Creates or updates an extmark.
-///
-/// To create a new extmark, pass id=0. The extmark id will be returned.
-/// To move an existing mark, pass its id.
-///
-/// It is also allowed to create a new mark by passing in a previously unused
-/// id, but the caller must then keep track of existing and unused ids itself.
-/// (Useful over RPC, to avoid waiting for the return value.)
-///
-/// Using the optional arguments, it is possible to use this to highlight
-/// a range of text, and also to associate virtual text to the mark.
-///
-/// @param buffer  Buffer handle, or 0 for current buffer
-/// @param ns_id  Namespace id from |nvim_create_namespace()|
-/// @param line  Line where to place the mark, 0-based. |api-indexing|
-/// @param col  Column where to place the mark, 0-based. |api-indexing|
-/// @param opts  Optional parameters.
-///               - id : id of the extmark to edit.
-///               - end_line : ending line of the mark, 0-based inclusive.
-///               - end_col : ending col of the mark, 0-based exclusive.
-///               - hl_group : name of the highlight group used to highlight
-///                   this mark.
-///               - hl_eol : when true, for a multiline highlight covering the
-///                          EOL of a line, continue the highlight for the rest
-///                          of the screen line (just like for diff and
-///                          cursorline highlight).
-///               - virt_text : virtual text to link to this mark.
-///                   A list of [text, highlight] tuples, each representing a
-///                   text chunk with specified highlight. `highlight` element
-///                   can either be a a single highlight group, or an array of
-///                   multiple highlight groups that will be stacked
-///                   (highest priority last). A highlight group can be supplied
-///                   either as a string or as an integer, the latter which
-///                   can be obtained using |nvim_get_hl_id_by_name|.
-///               - virt_text_pos : position of virtual text. Possible values:
-///                 - "eol": right after eol character (default)
-///                 - "overlay": display over the specified column, without
-///                              shifting the underlying text.
-///                 - "right_align": display right aligned in the window.
-///               - virt_text_win_col : position the virtual text at a fixed
-///                                     window column (starting from the first
-///                                     text column)
-///               - virt_text_hide : hide the virtual text when the background
-///                                  text is selected or hidden due to
-///                                  horizontal scroll 'nowrap'
-///               - hl_mode : control how highlights are combined with the
-///                           highlights of the text. Currently only affects
-///                           virt_text highlights, but might affect `hl_group`
-///                           in later versions.
-///                 - "replace": only show the virt_text color. This is the
-///                              default
-///                 - "combine": combine with background text color
-///                 - "blend": blend with background text color.
-///
-///               - virt_lines : virtual lines to add next to this mark
-///                   This should be an array over lines, where each line in
-///                   turn is an array over [text, highlight] tuples. In
-///                   general, buffer and window options do not affect the
-///                   display of the text. In particular 'wrap'
-///                   and 'linebreak' options do not take effect, so
-///                   the number of extra screen lines will always match
-///                   the size of the array. However the 'tabstop' buffer
-///                   option is still used for hard tabs. By default lines are
-///                   placed below the buffer line containing the mark.
-///
-///               - virt_lines_above: place virtual lines above instead.
-///               - virt_lines_leftcol: Place extmarks in the leftmost
-///                                     column of the window, bypassing
-///                                     sign and number columns.
-///
-///               - ephemeral : for use with |nvim_set_decoration_provider|
-///                   callbacks. The mark will only be used for the current
-///                   redraw cycle, and not be permantently stored in the
-///                   buffer.
-///               - right_gravity : boolean that indicates the direction
-///                   the extmark will be shifted in when new text is inserted
-///                   (true for right, false for left).  defaults to true.
-///               - end_right_gravity : boolean that indicates the direction
-///                   the extmark end position (if it exists) will be shifted
-///                   in when new text is inserted (true for right, false
-///                   for left). Defaults to false.
-///               - priority: a priority value for the highlight group. For
-///                   example treesitter highlighting uses a value of 100.
-/// @param[out]  err   Error details, if any
-/// @return Id of the created/updated extmark
-Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer col,
-                             Dict(set_extmark) *opts, Error *err)
-  FUNC_API_SINCE(7)
-{
-  Decoration decor = DECORATION_INIT;
-
-  buf_T *buf = find_buffer_by_handle(buffer, err);
-  if (!buf) {
-    goto error;
-  }
-
-  if (!ns_initialized((uint64_t)ns_id)) {
-    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
-    goto error;
-  }
-
-  uint64_t id = 0;
-  if (opts->id.type == kObjectTypeInteger && opts->id.data.integer > 0) {
-    id = (uint64_t)opts->id.data.integer;
-  } else if (HAS_KEY(opts->id)) {
-    api_set_error(err, kErrorTypeValidation, "id is not a positive integer");
-    goto error;
-  }
-
-  int line2 = -1;
-  if (opts->end_line.type == kObjectTypeInteger) {
-    Integer val = opts->end_line.data.integer;
-    if (val < 0 || val > buf->b_ml.ml_line_count) {
-      api_set_error(err, kErrorTypeValidation, "end_line value outside range");
-      goto error;
-    } else {
-      line2 = (int)val;
-    }
-  } else if (HAS_KEY(opts->end_line)) {
-    api_set_error(err, kErrorTypeValidation, "end_line is not an integer");
-    goto error;
-  }
-
-  colnr_T col2 = -1;
-  if (opts->end_col.type == kObjectTypeInteger) {
-    Integer val = opts->end_col.data.integer;
-    if (val < 0 || val > MAXCOL) {
-      api_set_error(err, kErrorTypeValidation, "end_col value outside range");
-      goto error;
-    } else {
-      col2 = (int)val;
-    }
-  } else if (HAS_KEY(opts->end_col)) {
-    api_set_error(err, kErrorTypeValidation, "end_col is not an integer");
-    goto error;
-  }
-
-  if (HAS_KEY(opts->hl_group)) {
-    decor.hl_id = object_to_hl_id(opts->hl_group, "hl_group", err);
-    if (ERROR_SET(err)) {
-      goto error;
-    }
-  }
-
-  if (opts->virt_text.type == kObjectTypeArray) {
-    decor.virt_text = parse_virt_text(opts->virt_text.data.array, err,
-                                      &decor.virt_text_width);
-    if (ERROR_SET(err)) {
-      goto error;
-    }
-  } else if (HAS_KEY(opts->virt_text)) {
-    api_set_error(err, kErrorTypeValidation, "virt_text is not an Array");
-    goto error;
-  }
-
-  if (opts->virt_text_pos.type == kObjectTypeString) {
-    String str = opts->virt_text_pos.data.string;
-    if (strequal("eol", str.data)) {
-      decor.virt_text_pos = kVTEndOfLine;
-    } else if (strequal("overlay", str.data)) {
-      decor.virt_text_pos = kVTOverlay;
-    } else if (strequal("right_align", str.data)) {
-      decor.virt_text_pos = kVTRightAlign;
-    } else {
-      api_set_error(err, kErrorTypeValidation, "virt_text_pos: invalid value");
-      goto error;
-    }
-  } else if (HAS_KEY(opts->virt_text_pos)) {
-    api_set_error(err, kErrorTypeValidation, "virt_text_pos is not a String");
-    goto error;
-  }
-
-  if (opts->virt_text_win_col.type == kObjectTypeInteger) {
-    decor.col = (int)opts->virt_text_win_col.data.integer;
-    decor.virt_text_pos = kVTWinCol;
-  } else if (HAS_KEY(opts->virt_text_win_col)) {
-    api_set_error(err, kErrorTypeValidation,
-                  "virt_text_win_col is not a Number of the correct size");
-    goto error;
-  }
-
-#define OPTION_TO_BOOL(target, name, val) \
-  target = api_object_to_bool(opts-> name, #name, val, err); \
-  if (ERROR_SET(err)) { \
-    goto error; \
-  }
-
-  OPTION_TO_BOOL(decor.virt_text_hide, virt_text_hide, false);
-  OPTION_TO_BOOL(decor.hl_eol, hl_eol, false);
-
-  if (opts->hl_mode.type == kObjectTypeString) {
-    String str = opts->hl_mode.data.string;
-    if (strequal("replace", str.data)) {
-      decor.hl_mode = kHlModeReplace;
-    } else if (strequal("combine", str.data)) {
-      decor.hl_mode = kHlModeCombine;
-    } else if (strequal("blend", str.data)) {
-      decor.hl_mode = kHlModeBlend;
-    } else {
-      api_set_error(err, kErrorTypeValidation,
-                    "virt_text_pos: invalid value");
-      goto error;
-    }
-  } else if (HAS_KEY(opts->hl_mode)) {
-    api_set_error(err, kErrorTypeValidation, "hl_mode is not a String");
-    goto error;
-  }
-
-  bool virt_lines_leftcol = false;
-  OPTION_TO_BOOL(virt_lines_leftcol, virt_lines_leftcol, false);
-
-  if (opts->virt_lines.type == kObjectTypeArray) {
-    Array a = opts->virt_lines.data.array;
-    for (size_t j = 0; j < a.size; j++) {
-      if (a.items[j].type != kObjectTypeArray) {
-        api_set_error(err, kErrorTypeValidation, "virt_text_line item is not an Array");
-        goto error;
-      }
-      int dummig;
-      VirtText jtem = parse_virt_text(a.items[j].data.array, err, &dummig);
-      kv_push(decor.virt_lines, ((struct virt_line){ jtem, virt_lines_leftcol }));
-      if (ERROR_SET(err)) {
-        goto error;
-      }
-    }
-  } else if (HAS_KEY(opts->virt_lines)) {
-    api_set_error(err, kErrorTypeValidation, "virt_lines is not an Array");
-    goto error;
-  }
-
-
-  OPTION_TO_BOOL(decor.virt_lines_above, virt_lines_above, false);
-
-  if (opts->priority.type == kObjectTypeInteger) {
-    Integer val = opts->priority.data.integer;
-
-    if (val < 0 || val > UINT16_MAX) {
-      api_set_error(err, kErrorTypeValidation, "priority is not a valid value");
-      goto error;
-    }
-    decor.priority = (DecorPriority)val;
-  } else if (HAS_KEY(opts->priority)) {
-    api_set_error(err, kErrorTypeValidation, "priority is not a Number of the correct size");
-    goto error;
-  }
-
-  bool right_gravity = true;
-  OPTION_TO_BOOL(right_gravity, right_gravity, true);
-
-  // Only error out if they try to set end_right_gravity without
-  // setting end_col or end_line
-  if (line2 == -1 && col2 == -1 && HAS_KEY(opts->end_right_gravity)) {
-    api_set_error(err, kErrorTypeValidation,
-                  "cannot set end_right_gravity without setting end_line or end_col");
-    goto error;
-  }
-
-  bool end_right_gravity = false;
-  OPTION_TO_BOOL(end_right_gravity, end_right_gravity, false);
-
-  size_t len = 0;
-
-  bool ephemeral = false;
-  OPTION_TO_BOOL(ephemeral, ephemeral, false);
-
-  if (line < 0 || line > buf->b_ml.ml_line_count) {
-    api_set_error(err, kErrorTypeValidation, "line value outside range");
-    goto error;
-  } else if (line < buf->b_ml.ml_line_count) {
-    len = ephemeral ? MAXCOL : STRLEN(ml_get_buf(buf, (linenr_T)line+1, false));
-  }
-
-  if (col == -1) {
-    col = (Integer)len;
-  } else if (col < -1 || col > (Integer)len) {
-    api_set_error(err, kErrorTypeValidation, "col value outside range");
-    goto error;
-  }
-
-  if (col2 >= 0) {
-    if (line2 >= 0 && line2 < buf->b_ml.ml_line_count) {
-      len = ephemeral ? MAXCOL : STRLEN(ml_get_buf(buf, (linenr_T)line2 + 1, false));
-    } else if (line2 == buf->b_ml.ml_line_count) {
-      // We are trying to add an extmark past final newline
-      len = 0;
-    } else {
-      // reuse len from before
-      line2 = (int)line;
-    }
-    if (col2 > (Integer)len) {
-      api_set_error(err, kErrorTypeValidation, "end_col value outside range");
-      goto error;
-    }
-  } else if (line2 >= 0) {
-    col2 = 0;
-  }
-
-  Decoration *d = NULL;
-
-  if (ephemeral) {
-    d = &decor;
-  } else if (kv_size(decor.virt_text) || kv_size(decor.virt_lines)
-             || decor.priority != DECOR_PRIORITY_BASE
-             || decor.hl_eol) {
-    // TODO(bfredl): this is a bit sketchy. eventually we should
-    // have predefined decorations for both marks/ephemerals
-    d = xcalloc(1, sizeof(*d));
-    *d = decor;
-  } else if (decor.hl_id) {
-    d = decor_hl(decor.hl_id);
-  }
-
-  // TODO(bfredl): synergize these two branches even more
-  if (ephemeral && decor_state.buf == buf) {
-    decor_add_ephemeral((int)line, (int)col, line2, col2, &decor);
-  } else {
-    if (ephemeral) {
-      api_set_error(err, kErrorTypeException, "not yet implemented");
-      goto error;
-    }
-
-    extmark_set(buf, (uint64_t)ns_id, &id, (int)line, (colnr_T)col, line2, col2,
-                d, right_gravity, end_right_gravity, kExtmarkNoUndo);
-
-    if (kv_size(decor.virt_lines)) {
-      redraw_buf_line_later(buf, MIN(buf->b_ml.ml_line_count, line+1+(decor.virt_lines_above?0:1)));
-    }
-  }
-
-  return (Integer)id;
-
-error:
-  clear_virttext(&decor.virt_text);
-  return 0;
-}
-
-/// Removes an extmark.
-///
-/// @param buffer Buffer handle, or 0 for current buffer
-/// @param ns_id Namespace id from |nvim_create_namespace()|
-/// @param id Extmark id
-/// @param[out] err   Error details, if any
-/// @return true if the extmark was found, else false
-Boolean nvim_buf_del_extmark(Buffer buffer, Integer ns_id, Integer id, Error *err)
-  FUNC_API_SINCE(7)
-{
-  buf_T *buf = find_buffer_by_handle(buffer, err);
-
-  if (!buf) {
-    return false;
-  }
-  if (!ns_initialized((uint64_t)ns_id)) {
-    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
-    return false;
-  }
-
-  return extmark_del(buf, (uint64_t)ns_id, (uint64_t)id);
-}
-
-/// Adds a highlight to buffer.
-///
-/// Useful for plugins that dynamically generate highlights to a buffer
-/// (like a semantic highlighter or linter). The function adds a single
-/// highlight to a buffer. Unlike |matchaddpos()| highlights follow changes to
-/// line numbering (as lines are inserted/removed above the highlighted line),
-/// like signs and marks do.
-///
-/// Namespaces are used for batch deletion/updating of a set of highlights. To
-/// create a namespace, use |nvim_create_namespace()| which returns a namespace
-/// id. Pass it in to this function as `ns_id` to add highlights to the
-/// namespace. All highlights in the same namespace can then be cleared with
-/// single call to |nvim_buf_clear_namespace()|. If the highlight never will be
-/// deleted by an API call, pass `ns_id = -1`.
-///
-/// As a shorthand, `ns_id = 0` can be used to create a new namespace for the
-/// highlight, the allocated id is then returned. If `hl_group` is the empty
-/// string no highlight is added, but a new `ns_id` is still returned. This is
-/// supported for backwards compatibility, new code should use
-/// |nvim_create_namespace()| to create a new empty namespace.
-///
-/// @param buffer     Buffer handle, or 0 for current buffer
-/// @param ns_id      namespace to use or -1 for ungrouped highlight
-/// @param hl_group   Name of the highlight group to use
-/// @param line       Line to highlight (zero-indexed)
-/// @param col_start  Start of (byte-indexed) column range to highlight
-/// @param col_end    End of (byte-indexed) column range to highlight,
-///                   or -1 to highlight to end of line
-/// @param[out] err   Error details, if any
-/// @return The ns_id that was used
-Integer nvim_buf_add_highlight(Buffer buffer, Integer ns_id, String hl_group, Integer line,
-                               Integer col_start, Integer col_end, Error *err)
-  FUNC_API_SINCE(1)
-{
-  buf_T *buf = find_buffer_by_handle(buffer, err);
-  if (!buf) {
-    return 0;
-  }
-
-  if (line < 0 || line >= MAXLNUM) {
-    api_set_error(err, kErrorTypeValidation, "Line number outside range");
-    return 0;
-  }
-  if (col_start < 0 || col_start > MAXCOL) {
-    api_set_error(err, kErrorTypeValidation, "Column value outside range");
-    return 0;
-  }
-  if (col_end < 0 || col_end > MAXCOL) {
-    col_end = MAXCOL;
-  }
-
-  uint64_t ns = src2ns(&ns_id);
-
-  if (!(line < buf->b_ml.ml_line_count)) {
-    // safety check, we can't add marks outside the range
-    return ns_id;
-  }
-
-  int hl_id = 0;
-  if (hl_group.size > 0) {
-    hl_id = syn_check_group(hl_group.data, (int)hl_group.size);
-  } else {
-    return ns_id;
-  }
-
-  int end_line = (int)line;
-  if (col_end == MAXCOL) {
-    col_end = 0;
-    end_line++;
-  }
-
-  extmark_set(buf, ns, NULL,
-              (int)line, (colnr_T)col_start,
-              end_line, (colnr_T)col_end,
-              decor_hl(hl_id), true, false, kExtmarkNoUndo);
-  return ns_id;
-}
-
-/// Clears namespaced objects (highlights, extmarks, virtual text) from
-/// a region.
-///
-/// Lines are 0-indexed. |api-indexing|  To clear the namespace in the entire
-/// buffer, specify line_start=0 and line_end=-1.
-///
-/// @param buffer     Buffer handle, or 0 for current buffer
-/// @param ns_id      Namespace to clear, or -1 to clear all namespaces.
-/// @param line_start Start of range of lines to clear
-/// @param line_end   End of range of lines to clear (exclusive) or -1 to clear
-///                   to end of buffer.
-/// @param[out] err   Error details, if any
-void nvim_buf_clear_namespace(Buffer buffer, Integer ns_id, Integer line_start, Integer line_end,
-                              Error *err)
-  FUNC_API_SINCE(5)
-{
-  buf_T *buf = find_buffer_by_handle(buffer, err);
-  if (!buf) {
-    return;
-  }
-
-  if (line_start < 0 || line_start >= MAXLNUM) {
-    api_set_error(err, kErrorTypeValidation, "Line number outside range");
-    return;
-  }
-  if (line_end < 0 || line_end > MAXLNUM) {
-    line_end = MAXLNUM;
-  }
-  extmark_clear(buf, (ns_id < 0 ? 0 : (uint64_t)ns_id),
-                (int)line_start, 0,
-                (int)line_end-1, MAXCOL);
-}
 
 /// call a function with buffer as temporary current buffer
 ///
diff --git a/src/nvim/api/buffer.h b/src/nvim/api/buffer.h
index 9aa898f7da..1c4a93a587 100644
--- a/src/nvim/api/buffer.h
+++ b/src/nvim/api/buffer.h
@@ -1,8 +1,6 @@
 #ifndef NVIM_API_BUFFER_H
 #define NVIM_API_BUFFER_H
 
-#include <stdint.h>
-
 #include "nvim/api/private/defs.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
diff --git a/src/nvim/api/deprecated.c b/src/nvim/api/deprecated.c
index 907d09e5b7..815dd70a52 100644
--- a/src/nvim/api/deprecated.c
+++ b/src/nvim/api/deprecated.c
@@ -8,6 +8,7 @@
 
 #include "nvim/api/buffer.h"
 #include "nvim/api/deprecated.h"
+#include "nvim/api/extmark.h"
 #include "nvim/api/private/defs.h"
 #include "nvim/api/private/helpers.h"
 #include "nvim/api/vim.h"
diff --git a/src/nvim/api/extmark.c b/src/nvim/api/extmark.c
new file mode 100644
index 0000000000..e6756315c6
--- /dev/null
+++ b/src/nvim/api/extmark.c
@@ -0,0 +1,896 @@
+// This is an open source non-commercial project. Dear PVS-Studio, please check
+// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "nvim/api/extmark.h"
+#include "nvim/api/private/defs.h"
+#include "nvim/api/private/helpers.h"
+#include "nvim/extmark.h"
+#include "nvim/lua/executor.h"
+#include "nvim/memline.h"
+#include "nvim/screen.h"
+#include "nvim/syntax.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "api/extmark.c.generated.h"
+#endif
+
+void api_extmark_free_all_mem(void)
+{
+  String name;
+  handle_T id;
+  map_foreach(&namespace_ids, name, id, {
+    (void)id;
+    xfree(name.data);
+  })
+  map_destroy(String, handle_T)(&namespace_ids);
+}
+
+/// Creates a new \*namespace\* or gets an existing one.
+///
+/// Namespaces are used for buffer highlights and virtual text, see
+/// |nvim_buf_add_highlight()| and |nvim_buf_set_extmark()|.
+///
+/// Namespaces can be named or anonymous. If `name` matches an existing
+/// namespace, the associated id is returned. If `name` is an empty string
+/// a new, anonymous namespace is created.
+///
+/// @param name Namespace name or empty string
+/// @return Namespace id
+Integer nvim_create_namespace(String name)
+  FUNC_API_SINCE(5)
+{
+  handle_T id = map_get(String, handle_T)(&namespace_ids, name);
+  if (id > 0) {
+    return id;
+  }
+  id = next_namespace_id++;
+  if (name.size > 0) {
+    String name_alloc = copy_string(name);
+    map_put(String, handle_T)(&namespace_ids, name_alloc, id);
+  }
+  return (Integer)id;
+}
+
+/// Gets existing, non-anonymous namespaces.
+///
+/// @return dict that maps from names to namespace ids.
+Dictionary nvim_get_namespaces(void)
+  FUNC_API_SINCE(5)
+{
+  Dictionary retval = ARRAY_DICT_INIT;
+  String name;
+  handle_T id;
+
+  map_foreach(&namespace_ids, name, id, {
+    PUT(retval, name.data, INTEGER_OBJ(id));
+  })
+
+  return retval;
+}
+
+const char *describe_ns(NS ns_id)
+{
+  String name;
+  handle_T id;
+  map_foreach(&namespace_ids, name, id, {
+    if ((NS)id == ns_id && name.size) {
+      return name.data;
+    }
+  })
+  return "(UNKNOWN PLUGIN)";
+}
+
+// Is the Namespace in use?
+static bool ns_initialized(uint64_t ns)
+{
+  if (ns < 1) {
+    return false;
+  }
+  return ns < (uint64_t)next_namespace_id;
+}
+
+
+
+static Array extmark_to_array(ExtmarkInfo extmark, bool id, bool add_dict)
+{
+  Array rv = ARRAY_DICT_INIT;
+  if (id) {
+    ADD(rv, INTEGER_OBJ((Integer)extmark.mark_id));
+  }
+  ADD(rv, INTEGER_OBJ(extmark.row));
+  ADD(rv, INTEGER_OBJ(extmark.col));
+
+  if (add_dict) {
+    Dictionary dict = ARRAY_DICT_INIT;
+
+    if (extmark.end_row >= 0) {
+      PUT(dict, "end_row", INTEGER_OBJ(extmark.end_row));
+      PUT(dict, "end_col", INTEGER_OBJ(extmark.end_col));
+    }
+
+    if (extmark.decor) {
+      Decoration *decor = extmark.decor;
+      if (decor->hl_id) {
+        String name = cstr_to_string((const char *)syn_id2name(decor->hl_id));
+        PUT(dict, "hl_group", STRING_OBJ(name));
+      }
+      if (kv_size(decor->virt_text)) {
+        Array chunks = ARRAY_DICT_INIT;
+        for (size_t i = 0; i < decor->virt_text.size; i++) {
+          Array chunk = ARRAY_DICT_INIT;
+          VirtTextChunk *vtc = &decor->virt_text.items[i];
+          ADD(chunk, STRING_OBJ(cstr_to_string(vtc->text)));
+          if (vtc->hl_id > 0) {
+            ADD(chunk,
+                STRING_OBJ(cstr_to_string((const char *)syn_id2name(vtc->hl_id))));
+          }
+          ADD(chunks, ARRAY_OBJ(chunk));
+        }
+        PUT(dict, "virt_text", ARRAY_OBJ(chunks));
+      }
+
+      PUT(dict, "priority", INTEGER_OBJ(decor->priority));
+    }
+
+    if (dict.size) {
+      ADD(rv, DICTIONARY_OBJ(dict));
+    }
+  }
+
+  return rv;
+}
+
+/// Gets the position (0-indexed) of an extmark.
+///
+/// @param buffer  Buffer handle, or 0 for current buffer
+/// @param ns_id  Namespace id from |nvim_create_namespace()|
+/// @param id  Extmark id
+/// @param opts  Optional parameters. Keys:
+///          - details: Whether to include the details dict
+/// @param[out] err   Error details, if any
+/// @return 0-indexed (row, col) tuple or empty list () if extmark id was
+/// absent
+ArrayOf(Integer) nvim_buf_get_extmark_by_id(Buffer buffer, Integer ns_id,
+                                            Integer id, Dictionary opts,
+                                            Error *err)
+  FUNC_API_SINCE(7)
+{
+  Array rv = ARRAY_DICT_INIT;
+
+  buf_T *buf = find_buffer_by_handle(buffer, err);
+
+  if (!buf) {
+    return rv;
+  }
+
+  if (!ns_initialized((uint64_t)ns_id)) {
+    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
+    return rv;
+  }
+
+  bool details = false;
+  for (size_t i = 0; i < opts.size; i++) {
+    String k = opts.items[i].key;
+    Object *v = &opts.items[i].value;
+    if (strequal("details", k.data)) {
+      if (v->type == kObjectTypeBoolean) {
+        details = v->data.boolean;
+      } else if (v->type == kObjectTypeInteger) {
+        details = v->data.integer;
+      } else {
+        api_set_error(err, kErrorTypeValidation, "details is not an boolean");
+        return rv;
+      }
+    } else {
+      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
+      return rv;
+    }
+  }
+
+
+  ExtmarkInfo extmark = extmark_from_id(buf, (uint64_t)ns_id, (uint64_t)id);
+  if (extmark.row < 0) {
+    return rv;
+  }
+  return extmark_to_array(extmark, false, details);
+}
+
+/// Gets extmarks in "traversal order" from a |charwise| region defined by
+/// buffer positions (inclusive, 0-indexed |api-indexing|).
+///
+/// Region can be given as (row,col) tuples, or valid extmark ids (whose
+/// positions define the bounds). 0 and -1 are understood as (0,0) and (-1,-1)
+/// respectively, thus the following are equivalent:
+///
+/// <pre>
+///   nvim_buf_get_extmarks(0, my_ns, 0, -1, {})
+///   nvim_buf_get_extmarks(0, my_ns, [0,0], [-1,-1], {})
+/// </pre>
+///
+/// If `end` is less than `start`, traversal works backwards. (Useful
+/// with `limit`, to get the first marks prior to a given position.)
+///
+/// Example:
+///
+/// <pre>
+///   local a   = vim.api
+///   local pos = a.nvim_win_get_cursor(0)
+///   local ns  = a.nvim_create_namespace('my-plugin')
+///   -- Create new extmark at line 1, column 1.
+///   local m1  = a.nvim_buf_set_extmark(0, ns, 0, 0, 0, {})
+///   -- Create new extmark at line 3, column 1.
+///   local m2  = a.nvim_buf_set_extmark(0, ns, 0, 2, 0, {})
+///   -- Get extmarks only from line 3.
+///   local ms  = a.nvim_buf_get_extmarks(0, ns, {2,0}, {2,0}, {})
+///   -- Get all marks in this buffer + namespace.
+///   local all = a.nvim_buf_get_extmarks(0, ns, 0, -1, {})
+///   print(vim.inspect(ms))
+/// </pre>
+///
+/// @param buffer  Buffer handle, or 0 for current buffer
+/// @param ns_id  Namespace id from |nvim_create_namespace()|
+/// @param start  Start of range: a 0-indexed (row, col) or valid extmark id
+/// (whose position defines the bound). |api-indexing|
+/// @param end  End of range (inclusive): a 0-indexed (row, col) or valid
+/// extmark id (whose position defines the bound). |api-indexing|
+/// @param opts  Optional parameters. Keys:
+///          - limit:  Maximum number of marks to return
+///          - details Whether to include the details dict
+/// @param[out] err   Error details, if any
+/// @return List of [extmark_id, row, col] tuples in "traversal order".
+Array nvim_buf_get_extmarks(Buffer buffer, Integer ns_id, Object start, Object end, Dictionary opts,
+                            Error *err)
+  FUNC_API_SINCE(7)
+{
+  Array rv = ARRAY_DICT_INIT;
+
+  buf_T *buf = find_buffer_by_handle(buffer, err);
+  if (!buf) {
+    return rv;
+  }
+
+  if (!ns_initialized((uint64_t)ns_id)) {
+    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
+    return rv;
+  }
+
+  Integer limit = -1;
+  bool details = false;
+
+  for (size_t i = 0; i < opts.size; i++) {
+    String k = opts.items[i].key;
+    Object *v = &opts.items[i].value;
+    if (strequal("limit", k.data)) {
+      if (v->type != kObjectTypeInteger) {
+        api_set_error(err, kErrorTypeValidation, "limit is not an integer");
+        return rv;
+      }
+      limit = v->data.integer;
+    } else if (strequal("details", k.data)) {
+      if (v->type == kObjectTypeBoolean) {
+        details = v->data.boolean;
+      } else if (v->type == kObjectTypeInteger) {
+        details = v->data.integer;
+      } else {
+        api_set_error(err, kErrorTypeValidation, "details is not an boolean");
+        return rv;
+      }
+    } else {
+      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
+      return rv;
+    }
+  }
+
+  if (limit == 0) {
+    return rv;
+  } else if (limit < 0) {
+    limit = INT64_MAX;
+  }
+
+
+  bool reverse = false;
+
+  int l_row;
+  colnr_T l_col;
+  if (!extmark_get_index_from_obj(buf, ns_id, start, &l_row, &l_col, err)) {
+    return rv;
+  }
+
+  int u_row;
+  colnr_T u_col;
+  if (!extmark_get_index_from_obj(buf, ns_id, end, &u_row, &u_col, err)) {
+    return rv;
+  }
+
+  if (l_row > u_row || (l_row == u_row && l_col > u_col)) {
+    reverse = true;
+  }
+
+
+  ExtmarkInfoArray marks = extmark_get(buf, (uint64_t)ns_id, l_row, l_col,
+                                       u_row, u_col, (int64_t)limit, reverse);
+
+  for (size_t i = 0; i < kv_size(marks); i++) {
+    ADD(rv, ARRAY_OBJ(extmark_to_array(kv_A(marks, i), true, (bool)details)));
+  }
+
+  kv_destroy(marks);
+  return rv;
+}
+
+/// Creates or updates an extmark.
+///
+/// To create a new extmark, pass id=0. The extmark id will be returned.
+/// To move an existing mark, pass its id.
+///
+/// It is also allowed to create a new mark by passing in a previously unused
+/// id, but the caller must then keep track of existing and unused ids itself.
+/// (Useful over RPC, to avoid waiting for the return value.)
+///
+/// Using the optional arguments, it is possible to use this to highlight
+/// a range of text, and also to associate virtual text to the mark.
+///
+/// @param buffer  Buffer handle, or 0 for current buffer
+/// @param ns_id  Namespace id from |nvim_create_namespace()|
+/// @param line  Line where to place the mark, 0-based. |api-indexing|
+/// @param col  Column where to place the mark, 0-based. |api-indexing|
+/// @param opts  Optional parameters.
+///               - id : id of the extmark to edit.
+///               - end_line : ending line of the mark, 0-based inclusive.
+///               - end_col : ending col of the mark, 0-based exclusive.
+///               - hl_group : name of the highlight group used to highlight
+///                   this mark.
+///               - hl_eol : when true, for a multiline highlight covering the
+///                          EOL of a line, continue the highlight for the rest
+///                          of the screen line (just like for diff and
+///                          cursorline highlight).
+///               - virt_text : virtual text to link to this mark.
+///                   A list of [text, highlight] tuples, each representing a
+///                   text chunk with specified highlight. `highlight` element
+///                   can either be a a single highlight group, or an array of
+///                   multiple highlight groups that will be stacked
+///                   (highest priority last). A highlight group can be supplied
+///                   either as a string or as an integer, the latter which
+///                   can be obtained using |nvim_get_hl_id_by_name|.
+///               - virt_text_pos : position of virtual text. Possible values:
+///                 - "eol": right after eol character (default)
+///                 - "overlay": display over the specified column, without
+///                              shifting the underlying text.
+///                 - "right_align": display right aligned in the window.
+///               - virt_text_win_col : position the virtual text at a fixed
+///                                     window column (starting from the first
+///                                     text column)
+///               - virt_text_hide : hide the virtual text when the background
+///                                  text is selected or hidden due to
+///                                  horizontal scroll 'nowrap'
+///               - hl_mode : control how highlights are combined with the
+///                           highlights of the text. Currently only affects
+///                           virt_text highlights, but might affect `hl_group`
+///                           in later versions.
+///                 - "replace": only show the virt_text color. This is the
+///                              default
+///                 - "combine": combine with background text color
+///                 - "blend": blend with background text color.
+///
+///               - virt_lines : virtual lines to add next to this mark
+///                   This should be an array over lines, where each line in
+///                   turn is an array over [text, highlight] tuples. In
+///                   general, buffer and window options do not affect the
+///                   display of the text. In particular 'wrap'
+///                   and 'linebreak' options do not take effect, so
+///                   the number of extra screen lines will always match
+///                   the size of the array. However the 'tabstop' buffer
+///                   option is still used for hard tabs. By default lines are
+///                   placed below the buffer line containing the mark.
+///
+///               - virt_lines_above: place virtual lines above instead.
+///               - virt_lines_leftcol: Place extmarks in the leftmost
+///                                     column of the window, bypassing
+///                                     sign and number columns.
+///
+///               - ephemeral : for use with |nvim_set_decoration_provider|
+///                   callbacks. The mark will only be used for the current
+///                   redraw cycle, and not be permantently stored in the
+///                   buffer.
+///               - right_gravity : boolean that indicates the direction
+///                   the extmark will be shifted in when new text is inserted
+///                   (true for right, false for left).  defaults to true.
+///               - end_right_gravity : boolean that indicates the direction
+///                   the extmark end position (if it exists) will be shifted
+///                   in when new text is inserted (true for right, false
+///                   for left). Defaults to false.
+///               - priority: a priority value for the highlight group. For
+///                   example treesitter highlighting uses a value of 100.
+/// @param[out]  err   Error details, if any
+/// @return Id of the created/updated extmark
+Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer col,
+                             Dict(set_extmark) *opts, Error *err)
+  FUNC_API_SINCE(7)
+{
+  Decoration decor = DECORATION_INIT;
+
+  buf_T *buf = find_buffer_by_handle(buffer, err);
+  if (!buf) {
+    goto error;
+  }
+
+  if (!ns_initialized((uint64_t)ns_id)) {
+    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
+    goto error;
+  }
+
+  uint64_t id = 0;
+  if (opts->id.type == kObjectTypeInteger && opts->id.data.integer > 0) {
+    id = (uint64_t)opts->id.data.integer;
+  } else if (HAS_KEY(opts->id)) {
+    api_set_error(err, kErrorTypeValidation, "id is not a positive integer");
+    goto error;
+  }
+
+  int line2 = -1;
+  if (opts->end_line.type == kObjectTypeInteger) {
+    Integer val = opts->end_line.data.integer;
+    if (val < 0 || val > buf->b_ml.ml_line_count) {
+      api_set_error(err, kErrorTypeValidation, "end_line value outside range");
+      goto error;
+    } else {
+      line2 = (int)val;
+    }
+  } else if (HAS_KEY(opts->end_line)) {
+    api_set_error(err, kErrorTypeValidation, "end_line is not an integer");
+    goto error;
+  }
+
+  colnr_T col2 = -1;
+  if (opts->end_col.type == kObjectTypeInteger) {
+    Integer val = opts->end_col.data.integer;
+    if (val < 0 || val > MAXCOL) {
+      api_set_error(err, kErrorTypeValidation, "end_col value outside range");
+      goto error;
+    } else {
+      col2 = (int)val;
+    }
+  } else if (HAS_KEY(opts->end_col)) {
+    api_set_error(err, kErrorTypeValidation, "end_col is not an integer");
+    goto error;
+  }
+
+  if (HAS_KEY(opts->hl_group)) {
+    decor.hl_id = object_to_hl_id(opts->hl_group, "hl_group", err);
+    if (ERROR_SET(err)) {
+      goto error;
+    }
+  }
+
+  if (opts->virt_text.type == kObjectTypeArray) {
+    decor.virt_text = parse_virt_text(opts->virt_text.data.array, err,
+                                      &decor.virt_text_width);
+    if (ERROR_SET(err)) {
+      goto error;
+    }
+  } else if (HAS_KEY(opts->virt_text)) {
+    api_set_error(err, kErrorTypeValidation, "virt_text is not an Array");
+    goto error;
+  }
+
+  if (opts->virt_text_pos.type == kObjectTypeString) {
+    String str = opts->virt_text_pos.data.string;
+    if (strequal("eol", str.data)) {
+      decor.virt_text_pos = kVTEndOfLine;
+    } else if (strequal("overlay", str.data)) {
+      decor.virt_text_pos = kVTOverlay;
+    } else if (strequal("right_align", str.data)) {
+      decor.virt_text_pos = kVTRightAlign;
+    } else {
+      api_set_error(err, kErrorTypeValidation, "virt_text_pos: invalid value");
+      goto error;
+    }
+  } else if (HAS_KEY(opts->virt_text_pos)) {
+    api_set_error(err, kErrorTypeValidation, "virt_text_pos is not a String");
+    goto error;
+  }
+
+  if (opts->virt_text_win_col.type == kObjectTypeInteger) {
+    decor.col = (int)opts->virt_text_win_col.data.integer;
+    decor.virt_text_pos = kVTWinCol;
+  } else if (HAS_KEY(opts->virt_text_win_col)) {
+    api_set_error(err, kErrorTypeValidation,
+                  "virt_text_win_col is not a Number of the correct size");
+    goto error;
+  }
+
+#define OPTION_TO_BOOL(target, name, val) \
+  target = api_object_to_bool(opts-> name, #name, val, err); \
+  if (ERROR_SET(err)) { \
+    goto error; \
+  }
+
+  OPTION_TO_BOOL(decor.virt_text_hide, virt_text_hide, false);
+  OPTION_TO_BOOL(decor.hl_eol, hl_eol, false);
+
+  if (opts->hl_mode.type == kObjectTypeString) {
+    String str = opts->hl_mode.data.string;
+    if (strequal("replace", str.data)) {
+      decor.hl_mode = kHlModeReplace;
+    } else if (strequal("combine", str.data)) {
+      decor.hl_mode = kHlModeCombine;
+    } else if (strequal("blend", str.data)) {
+      decor.hl_mode = kHlModeBlend;
+    } else {
+      api_set_error(err, kErrorTypeValidation,
+                    "virt_text_pos: invalid value");
+      goto error;
+    }
+  } else if (HAS_KEY(opts->hl_mode)) {
+    api_set_error(err, kErrorTypeValidation, "hl_mode is not a String");
+    goto error;
+  }
+
+  bool virt_lines_leftcol = false;
+  OPTION_TO_BOOL(virt_lines_leftcol, virt_lines_leftcol, false);
+
+  if (opts->virt_lines.type == kObjectTypeArray) {
+    Array a = opts->virt_lines.data.array;
+    for (size_t j = 0; j < a.size; j++) {
+      if (a.items[j].type != kObjectTypeArray) {
+        api_set_error(err, kErrorTypeValidation, "virt_text_line item is not an Array");
+        goto error;
+      }
+      int dummig;
+      VirtText jtem = parse_virt_text(a.items[j].data.array, err, &dummig);
+      kv_push(decor.virt_lines, ((struct virt_line){ jtem, virt_lines_leftcol }));
+      if (ERROR_SET(err)) {
+        goto error;
+      }
+    }
+  } else if (HAS_KEY(opts->virt_lines)) {
+    api_set_error(err, kErrorTypeValidation, "virt_lines is not an Array");
+    goto error;
+  }
+
+
+  OPTION_TO_BOOL(decor.virt_lines_above, virt_lines_above, false);
+
+  if (opts->priority.type == kObjectTypeInteger) {
+    Integer val = opts->priority.data.integer;
+
+    if (val < 0 || val > UINT16_MAX) {
+      api_set_error(err, kErrorTypeValidation, "priority is not a valid value");
+      goto error;
+    }
+    decor.priority = (DecorPriority)val;
+  } else if (HAS_KEY(opts->priority)) {
+    api_set_error(err, kErrorTypeValidation, "priority is not a Number of the correct size");
+    goto error;
+  }
+
+  bool right_gravity = true;
+  OPTION_TO_BOOL(right_gravity, right_gravity, true);
+
+  // Only error out if they try to set end_right_gravity without
+  // setting end_col or end_line
+  if (line2 == -1 && col2 == -1 && HAS_KEY(opts->end_right_gravity)) {
+    api_set_error(err, kErrorTypeValidation,
+                  "cannot set end_right_gravity without setting end_line or end_col");
+    goto error;
+  }
+
+  bool end_right_gravity = false;
+  OPTION_TO_BOOL(end_right_gravity, end_right_gravity, false);
+
+  size_t len = 0;
+
+  bool ephemeral = false;
+  OPTION_TO_BOOL(ephemeral, ephemeral, false);
+
+  if (line < 0 || line > buf->b_ml.ml_line_count) {
+    api_set_error(err, kErrorTypeValidation, "line value outside range");
+    goto error;
+  } else if (line < buf->b_ml.ml_line_count) {
+    len = ephemeral ? MAXCOL : STRLEN(ml_get_buf(buf, (linenr_T)line+1, false));
+  }
+
+  if (col == -1) {
+    col = (Integer)len;
+  } else if (col < -1 || col > (Integer)len) {
+    api_set_error(err, kErrorTypeValidation, "col value outside range");
+    goto error;
+  }
+
+  if (col2 >= 0) {
+    if (line2 >= 0 && line2 < buf->b_ml.ml_line_count) {
+      len = ephemeral ? MAXCOL : STRLEN(ml_get_buf(buf, (linenr_T)line2 + 1, false));
+    } else if (line2 == buf->b_ml.ml_line_count) {
+      // We are trying to add an extmark past final newline
+      len = 0;
+    } else {
+      // reuse len from before
+      line2 = (int)line;
+    }
+    if (col2 > (Integer)len) {
+      api_set_error(err, kErrorTypeValidation, "end_col value outside range");
+      goto error;
+    }
+  } else if (line2 >= 0) {
+    col2 = 0;
+  }
+
+  Decoration *d = NULL;
+
+  if (ephemeral) {
+    d = &decor;
+  } else if (kv_size(decor.virt_text) || kv_size(decor.virt_lines)
+             || decor.priority != DECOR_PRIORITY_BASE
+             || decor.hl_eol) {
+    // TODO(bfredl): this is a bit sketchy. eventually we should
+    // have predefined decorations for both marks/ephemerals
+    d = xcalloc(1, sizeof(*d));
+    *d = decor;
+  } else if (decor.hl_id) {
+    d = decor_hl(decor.hl_id);
+  }
+
+  // TODO(bfredl): synergize these two branches even more
+  if (ephemeral && decor_state.buf == buf) {
+    decor_add_ephemeral((int)line, (int)col, line2, col2, &decor);
+  } else {
+    if (ephemeral) {
+      api_set_error(err, kErrorTypeException, "not yet implemented");
+      goto error;
+    }
+
+    extmark_set(buf, (uint64_t)ns_id, &id, (int)line, (colnr_T)col, line2, col2,
+                d, right_gravity, end_right_gravity, kExtmarkNoUndo);
+
+    if (kv_size(decor.virt_lines)) {
+      redraw_buf_line_later(buf, MIN(buf->b_ml.ml_line_count, line+1+(decor.virt_lines_above?0:1)));
+    }
+  }
+
+  return (Integer)id;
+
+error:
+  clear_virttext(&decor.virt_text);
+  return 0;
+}
+
+/// Removes an extmark.
+///
+/// @param buffer Buffer handle, or 0 for current buffer
+/// @param ns_id Namespace id from |nvim_create_namespace()|
+/// @param id Extmark id
+/// @param[out] err   Error details, if any
+/// @return true if the extmark was found, else false
+Boolean nvim_buf_del_extmark(Buffer buffer, Integer ns_id, Integer id, Error *err)
+  FUNC_API_SINCE(7)
+{
+  buf_T *buf = find_buffer_by_handle(buffer, err);
+
+  if (!buf) {
+    return false;
+  }
+  if (!ns_initialized((uint64_t)ns_id)) {
+    api_set_error(err, kErrorTypeValidation, "Invalid ns_id");
+    return false;
+  }
+
+  return extmark_del(buf, (uint64_t)ns_id, (uint64_t)id);
+}
+
+uint64_t src2ns(Integer *src_id)
+{
+  if (*src_id == 0) {
+    *src_id = nvim_create_namespace((String)STRING_INIT);
+  }
+  if (*src_id < 0) {
+    return UINT64_MAX;
+  } else {
+    return (uint64_t)(*src_id);
+  }
+}
+
+/// Adds a highlight to buffer.
+///
+/// Useful for plugins that dynamically generate highlights to a buffer
+/// (like a semantic highlighter or linter). The function adds a single
+/// highlight to a buffer. Unlike |matchaddpos()| highlights follow changes to
+/// line numbering (as lines are inserted/removed above the highlighted line),
+/// like signs and marks do.
+///
+/// Namespaces are used for batch deletion/updating of a set of highlights. To
+/// create a namespace, use |nvim_create_namespace()| which returns a namespace
+/// id. Pass it in to this function as `ns_id` to add highlights to the
+/// namespace. All highlights in the same namespace can then be cleared with
+/// single call to |nvim_buf_clear_namespace()|. If the highlight never will be
+/// deleted by an API call, pass `ns_id = -1`.
+///
+/// As a shorthand, `ns_id = 0` can be used to create a new namespace for the
+/// highlight, the allocated id is then returned. If `hl_group` is the empty
+/// string no highlight is added, but a new `ns_id` is still returned. This is
+/// supported for backwards compatibility, new code should use
+/// |nvim_create_namespace()| to create a new empty namespace.
+///
+/// @param buffer     Buffer handle, or 0 for current buffer
+/// @param ns_id      namespace to use or -1 for ungrouped highlight
+/// @param hl_group   Name of the highlight group to use
+/// @param line       Line to highlight (zero-indexed)
+/// @param col_start  Start of (byte-indexed) column range to highlight
+/// @param col_end    End of (byte-indexed) column range to highlight,
+///                   or -1 to highlight to end of line
+/// @param[out] err   Error details, if any
+/// @return The ns_id that was used
+Integer nvim_buf_add_highlight(Buffer buffer, Integer ns_id, String hl_group, Integer line,
+                               Integer col_start, Integer col_end, Error *err)
+  FUNC_API_SINCE(1)
+{
+  buf_T *buf = find_buffer_by_handle(buffer, err);
+  if (!buf) {
+    return 0;
+  }
+
+  if (line < 0 || line >= MAXLNUM) {
+    api_set_error(err, kErrorTypeValidation, "Line number outside range");
+    return 0;
+  }
+  if (col_start < 0 || col_start > MAXCOL) {
+    api_set_error(err, kErrorTypeValidation, "Column value outside range");
+    return 0;
+  }
+  if (col_end < 0 || col_end > MAXCOL) {
+    col_end = MAXCOL;
+  }
+
+  uint64_t ns = src2ns(&ns_id);
+
+  if (!(line < buf->b_ml.ml_line_count)) {
+    // safety check, we can't add marks outside the range
+    return ns_id;
+  }
+
+  int hl_id = 0;
+  if (hl_group.size > 0) {
+    hl_id = syn_check_group(hl_group.data, (int)hl_group.size);
+  } else {
+    return ns_id;
+  }
+
+  int end_line = (int)line;
+  if (col_end == MAXCOL) {
+    col_end = 0;
+    end_line++;
+  }
+
+  extmark_set(buf, ns, NULL,
+              (int)line, (colnr_T)col_start,
+              end_line, (colnr_T)col_end,
+              decor_hl(hl_id), true, false, kExtmarkNoUndo);
+  return ns_id;
+}
+
+/// Clears namespaced objects (highlights, extmarks, virtual text) from
+/// a region.
+///
+/// Lines are 0-indexed. |api-indexing|  To clear the namespace in the entire
+/// buffer, specify line_start=0 and line_end=-1.
+///
+/// @param buffer     Buffer handle, or 0 for current buffer
+/// @param ns_id      Namespace to clear, or -1 to clear all namespaces.
+/// @param line_start Start of range of lines to clear
+/// @param line_end   End of range of lines to clear (exclusive) or -1 to clear
+///                   to end of buffer.
+/// @param[out] err   Error details, if any
+void nvim_buf_clear_namespace(Buffer buffer, Integer ns_id, Integer line_start, Integer line_end,
+                              Error *err)
+  FUNC_API_SINCE(5)
+{
+  buf_T *buf = find_buffer_by_handle(buffer, err);
+  if (!buf) {
+    return;
+  }
+
+  if (line_start < 0 || line_start >= MAXLNUM) {
+    api_set_error(err, kErrorTypeValidation, "Line number outside range");
+    return;
+  }
+  if (line_end < 0 || line_end > MAXLNUM) {
+    line_end = MAXLNUM;
+  }
+  extmark_clear(buf, (ns_id < 0 ? 0 : (uint64_t)ns_id),
+                (int)line_start, 0,
+                (int)line_end-1, MAXCOL);
+}
+
+/// Set or change decoration provider for a namespace
+///
+/// This is a very general purpose interface for having lua callbacks
+/// being triggered during the redraw code.
+///
+/// The expected usage is to set extmarks for the currently
+/// redrawn buffer. |nvim_buf_set_extmark| can be called to add marks
+/// on a per-window or per-lines basis. Use the `ephemeral` key to only
+/// use the mark for the current screen redraw (the callback will be called
+/// again for the next redraw ).
+///
+/// Note: this function should not be called often. Rather, the callbacks
+/// themselves can be used to throttle unneeded callbacks. the `on_start`
+/// callback can return `false` to disable the provider until the next redraw.
+/// Similarly, return `false` in `on_win` will skip the `on_lines` calls
+/// for that window (but any extmarks set in `on_win` will still be used).
+/// A plugin managing multiple sources of decoration should ideally only set
+/// one provider, and merge the sources internally. You can use multiple `ns_id`
+/// for the extmarks set/modified inside the callback anyway.
+///
+/// Note: doing anything other than setting extmarks is considered experimental.
+/// Doing things like changing options are not expliticly forbidden, but is
+/// likely to have unexpected consequences (such as 100% CPU consumption).
+/// doing `vim.rpcnotify` should be OK, but `vim.rpcrequest` is quite dubious
+/// for the moment.
+///
+/// @param ns_id  Namespace id from |nvim_create_namespace()|
+/// @param opts   Callbacks invoked during redraw:
+///             - on_start: called first on each screen redraw
+///                 ["start", tick]
+///             - on_buf: called for each buffer being redrawn (before window
+///                 callbacks)
+///                 ["buf", bufnr, tick]
+///             - on_win: called when starting to redraw a specific window.
+///                 ["win", winid, bufnr, topline, botline_guess]
+///             - on_line: called for each buffer line being redrawn. (The
+///                 interation with fold lines is subject to change)
+///                 ["win", winid, bufnr, row]
+///             - on_end: called at the end of a redraw cycle
+///                 ["end", tick]
+void nvim_set_decoration_provider(Integer ns_id, DictionaryOf(LuaRef) opts, Error *err)
+  FUNC_API_SINCE(7) FUNC_API_LUA_ONLY
+{
+  DecorProvider *p = get_decor_provider((NS)ns_id, true);
+  assert(p != NULL);
+  decor_provider_clear(p);
+
+  // regardless of what happens, it seems good idea to redraw
+  redraw_all_later(NOT_VALID);  // TODO(bfredl): too soon?
+
+  struct {
+    const char *name;
+    LuaRef *dest;
+  } cbs[] = {
+    { "on_start", &p->redraw_start },
+    { "on_buf", &p->redraw_buf },
+    { "on_win", &p->redraw_win },
+    { "on_line", &p->redraw_line },
+    { "on_end", &p->redraw_end },
+    { "_on_hl_def", &p->hl_def },
+    { NULL, NULL },
+  };
+
+  for (size_t i = 0; i < opts.size; i++) {
+    String k = opts.items[i].key;
+    Object *v = &opts.items[i].value;
+    size_t j;
+    for (j = 0; cbs[j].name && cbs[j].dest; j++) {
+      if (strequal(cbs[j].name, k.data)) {
+        if (v->type != kObjectTypeLuaRef) {
+          api_set_error(err, kErrorTypeValidation,
+                        "%s is not a function", cbs[j].name);
+          goto error;
+        }
+        *(cbs[j].dest) = v->data.luaref;
+        v->data.luaref = LUA_NOREF;
+        break;
+      }
+    }
+    if (!cbs[j].name) {
+      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
+      goto error;
+    }
+  }
+
+  p->active = true;
+  return;
+error:
+  decor_provider_clear(p);
+}
diff --git a/src/nvim/api/extmark.h b/src/nvim/api/extmark.h
new file mode 100644
index 0000000000..c5e463cd86
--- /dev/null
+++ b/src/nvim/api/extmark.h
@@ -0,0 +1,13 @@
+#ifndef NVIM_API_EXTMARK_H
+#define NVIM_API_EXTMARK_H
+
+#include "nvim/api/private/defs.h"
+#include "nvim/map.h"
+
+EXTERN Map(String, handle_T) namespace_ids INIT(= MAP_INIT);
+EXTERN handle_T next_namespace_id INIT(= 1);
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "api/extmark.h.generated.h"
+#endif
+#endif  // NVIM_API_EXTMARK_H
diff --git a/src/nvim/api/private/dispatch.c b/src/nvim/api/private/dispatch.c
index 519bf8ff14..79af9bf176 100644
--- a/src/nvim/api/private/dispatch.c
+++ b/src/nvim/api/private/dispatch.c
@@ -8,6 +8,7 @@
 
 #include "nvim/api/buffer.h"
 #include "nvim/api/deprecated.h"
+#include "nvim/api/extmark.h"
 #include "nvim/api/private/defs.h"
 #include "nvim/api/private/dispatch.h"
 #include "nvim/api/private/helpers.h"
diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index f1259c8a18..745681c3f8 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -1410,15 +1410,6 @@ ArrayOf(Dictionary) keymap_array(String mode, buf_T *buf)
   return mappings;
 }
 
-// Is the Namespace in use?
-bool ns_initialized(uint64_t ns)
-{
-  if (ns < 1) {
-    return false;
-  }
-  return ns < (uint64_t)next_namespace_id;
-}
-
 /// Gets the line and column of an extmark.
 ///
 /// Extmarks may be queried by position, name or even special names
@@ -1607,18 +1598,6 @@ free_exit:
   return hl_msg;
 }
 
-const char *describe_ns(NS ns_id)
-{
-  String name;
-  handle_T id;
-  map_foreach(&namespace_ids, name, id, {
-    if ((NS)id == ns_id && name.size) {
-      return name.data;
-    }
-  })
-  return "(UNKNOWN PLUGIN)";
-}
-
 bool api_dict_to_keydict(void *rv, field_hash hashy, Dictionary dict, Error *err)
 {
   for (size_t i = 0; i < dict.size; i++) {
diff --git a/src/nvim/api/tabpage.h b/src/nvim/api/tabpage.h
index a822844af9..2689cf6ae6 100644
--- a/src/nvim/api/tabpage.h
+++ b/src/nvim/api/tabpage.h
@@ -1,8 +1,6 @@
 #ifndef NVIM_API_TABPAGE_H
 #define NVIM_API_TABPAGE_H
 
-#include <stdint.h>
-
 #include "nvim/api/private/defs.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index b5cc02e761..7f442c8e52 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -59,17 +59,6 @@
 # include "api/vim.c.generated.h"
 #endif
 
-void api_vim_free_all_mem(void)
-{
-  String name;
-  handle_T id;
-  map_foreach(&namespace_ids, name, id, {
-    (void)id;
-    xfree(name.data);
-  })
-  map_destroy(String, handle_T)(&namespace_ids);
-}
-
 /// Executes Vimscript (multiline block of Ex-commands), like anonymous
 /// |:source|.
 ///
@@ -1414,49 +1403,6 @@ void nvim_set_current_tabpage(Tabpage tabpage, Error *err)
   }
 }
 
-/// Creates a new \*namespace\* or gets an existing one.
-///
-/// Namespaces are used for buffer highlights and virtual text, see
-/// |nvim_buf_add_highlight()| and |nvim_buf_set_extmark()|.
-///
-/// Namespaces can be named or anonymous. If `name` matches an existing
-/// namespace, the associated id is returned. If `name` is an empty string
-/// a new, anonymous namespace is created.
-///
-/// @param name Namespace name or empty string
-/// @return Namespace id
-Integer nvim_create_namespace(String name)
-  FUNC_API_SINCE(5)
-{
-  handle_T id = map_get(String, handle_T)(&namespace_ids, name);
-  if (id > 0) {
-    return id;
-  }
-  id = next_namespace_id++;
-  if (name.size > 0) {
-    String name_alloc = copy_string(name);
-    map_put(String, handle_T)(&namespace_ids, name_alloc, id);
-  }
-  return (Integer)id;
-}
-
-/// Gets existing, non-anonymous namespaces.
-///
-/// @return dict that maps from names to namespace ids.
-Dictionary nvim_get_namespaces(void)
-  FUNC_API_SINCE(5)
-{
-  Dictionary retval = ARRAY_DICT_INIT;
-  String name;
-  handle_T id;
-
-  map_foreach(&namespace_ids, name, id, {
-    PUT(retval, name.data, INTEGER_OBJ(id));
-  })
-
-  return retval;
-}
-
 /// Pastes at cursor, in any mode.
 ///
 /// Invokes the `vim.paste` handler, which handles each mode appropriately.
@@ -2745,96 +2691,6 @@ void nvim__screenshot(String path)
   ui_call_screenshot(path);
 }
 
-/// Set or change decoration provider for a namespace
-///
-/// This is a very general purpose interface for having lua callbacks
-/// being triggered during the redraw code.
-///
-/// The expected usage is to set extmarks for the currently
-/// redrawn buffer. |nvim_buf_set_extmark| can be called to add marks
-/// on a per-window or per-lines basis. Use the `ephemeral` key to only
-/// use the mark for the current screen redraw (the callback will be called
-/// again for the next redraw ).
-///
-/// Note: this function should not be called often. Rather, the callbacks
-/// themselves can be used to throttle unneeded callbacks. the `on_start`
-/// callback can return `false` to disable the provider until the next redraw.
-/// Similarly, return `false` in `on_win` will skip the `on_lines` calls
-/// for that window (but any extmarks set in `on_win` will still be used).
-/// A plugin managing multiple sources of decoration should ideally only set
-/// one provider, and merge the sources internally. You can use multiple `ns_id`
-/// for the extmarks set/modified inside the callback anyway.
-///
-/// Note: doing anything other than setting extmarks is considered experimental.
-/// Doing things like changing options are not expliticly forbidden, but is
-/// likely to have unexpected consequences (such as 100% CPU consumption).
-/// doing `vim.rpcnotify` should be OK, but `vim.rpcrequest` is quite dubious
-/// for the moment.
-///
-/// @param ns_id  Namespace id from |nvim_create_namespace()|
-/// @param opts   Callbacks invoked during redraw:
-///             - on_start: called first on each screen redraw
-///                 ["start", tick]
-///             - on_buf: called for each buffer being redrawn (before window
-///                 callbacks)
-///                 ["buf", bufnr, tick]
-///             - on_win: called when starting to redraw a specific window.
-///                 ["win", winid, bufnr, topline, botline_guess]
-///             - on_line: called for each buffer line being redrawn. (The
-///                 interation with fold lines is subject to change)
-///                 ["win", winid, bufnr, row]
-///             - on_end: called at the end of a redraw cycle
-///                 ["end", tick]
-void nvim_set_decoration_provider(Integer ns_id, DictionaryOf(LuaRef) opts, Error *err)
-  FUNC_API_SINCE(7) FUNC_API_LUA_ONLY
-{
-  DecorProvider *p = get_decor_provider((NS)ns_id, true);
-  assert(p != NULL);
-  decor_provider_clear(p);
-
-  // regardless of what happens, it seems good idea to redraw
-  redraw_all_later(NOT_VALID);  // TODO(bfredl): too soon?
-
-  struct {
-    const char *name;
-    LuaRef *dest;
-  } cbs[] = {
-    { "on_start", &p->redraw_start },
-    { "on_buf", &p->redraw_buf },
-    { "on_win", &p->redraw_win },
-    { "on_line", &p->redraw_line },
-    { "on_end", &p->redraw_end },
-    { "_on_hl_def", &p->hl_def },
-    { NULL, NULL },
-  };
-
-  for (size_t i = 0; i < opts.size; i++) {
-    String k = opts.items[i].key;
-    Object *v = &opts.items[i].value;
-    size_t j;
-    for (j = 0; cbs[j].name && cbs[j].dest; j++) {
-      if (strequal(cbs[j].name, k.data)) {
-        if (v->type != kObjectTypeLuaRef) {
-          api_set_error(err, kErrorTypeValidation,
-                        "%s is not a function", cbs[j].name);
-          goto error;
-        }
-        *(cbs[j].dest) = v->data.luaref;
-        v->data.luaref = LUA_NOREF;
-        break;
-      }
-    }
-    if (!cbs[j].name) {
-      api_set_error(err, kErrorTypeValidation, "unexpected key: %s", k.data);
-      goto error;
-    }
-  }
-
-  p->active = true;
-  return;
-error:
-  decor_provider_clear(p);
-}
 
 /// Deletes a uppercase/file named mark. See |mark-motions|.
 ///
diff --git a/src/nvim/api/vim.h b/src/nvim/api/vim.h
index 4fd353ce5c..de56c67665 100644
--- a/src/nvim/api/vim.h
+++ b/src/nvim/api/vim.h
@@ -1,13 +1,7 @@
 #ifndef NVIM_API_VIM_H
 #define NVIM_API_VIM_H
 
-#include <stdint.h>
-
 #include "nvim/api/private/defs.h"
-#include "nvim/map.h"
-
-EXTERN Map(String, handle_T) namespace_ids INIT(= MAP_INIT);
-EXTERN handle_T next_namespace_id INIT(= 1);
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "api/vim.h.generated.h"
diff --git a/src/nvim/api/win_config.h b/src/nvim/api/win_config.h
index 9271c35f23..d3e5ede5e9 100644
--- a/src/nvim/api/win_config.h
+++ b/src/nvim/api/win_config.h
@@ -1,8 +1,6 @@
 #ifndef NVIM_API_WIN_CONFIG_H
 #define NVIM_API_WIN_CONFIG_H
 
-#include <stdint.h>
-
 #include "nvim/api/private/defs.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
diff --git a/src/nvim/api/window.h b/src/nvim/api/window.h
index 632b160e62..0f36c12a9f 100644
--- a/src/nvim/api/window.h
+++ b/src/nvim/api/window.h
@@ -1,8 +1,6 @@
 #ifndef NVIM_API_WINDOW_H
 #define NVIM_API_WINDOW_H
 
-#include <stdint.h>
-
 #include "nvim/api/private/defs.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 558001cd62..17ab138d75 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -15,7 +15,7 @@
 
 #include "nvim/api/buffer.h"
 #include "nvim/api/private/defs.h"
-#include "nvim/api/vim.h"
+#include "nvim/api/extmark.h"
 #include "nvim/ascii.h"
 #include "nvim/buffer.h"
 #include "nvim/buffer_updates.h"
diff --git a/src/nvim/extmark.c b/src/nvim/extmark.c
index 05d1d69f9d..a3a7791d21 100644
--- a/src/nvim/extmark.c
+++ b/src/nvim/extmark.c
@@ -30,7 +30,7 @@
 
 #include <assert.h>
 
-#include "nvim/api/vim.h"
+#include "nvim/api/extmark.h"
 #include "nvim/buffer.h"
 #include "nvim/buffer_updates.h"
 #include "nvim/charset.h"
@@ -715,16 +715,3 @@ void extmark_move_region(buf_T *buf, int start_row, colnr_T start_col, bcount_t
                                   .data.move = move }));
   }
 }
-
-uint64_t src2ns(Integer *src_id)
-{
-  if (*src_id == 0) {
-    *src_id = nvim_create_namespace((String)STRING_INIT);
-  }
-  if (*src_id < 0) {
-    return UINT64_MAX;
-  } else {
-    return (uint64_t)(*src_id);
-  }
-}
-
diff --git a/src/nvim/main.c b/src/nvim/main.c
index 4b4ab687b2..c329c9a8f4 100644
--- a/src/nvim/main.c
+++ b/src/nvim/main.c
@@ -81,7 +81,7 @@
 #ifndef WIN32
 # include "nvim/os/pty_process_unix.h"
 #endif
-#include "nvim/api/vim.h"
+#include "nvim/api/extmark.h"
 
 // values for "window_layout"
 #define WIN_HOR     1       // "-o" horizontally split windows
diff --git a/src/nvim/memory.c b/src/nvim/memory.c
index 5e6c6a8189..5345580b93 100644
--- a/src/nvim/memory.c
+++ b/src/nvim/memory.c
@@ -8,7 +8,7 @@
 #include <stdbool.h>
 #include <string.h>
 
-#include "nvim/api/vim.h"
+#include "nvim/api/extmark.h"
 #include "nvim/context.h"
 #include "nvim/decoration.h"
 #include "nvim/eval.h"
@@ -679,7 +679,7 @@ void free_all_mem(void)
   }
 
   eval_clear();
-  api_vim_free_all_mem();
+  api_extmark_free_all_mem();
   ctx_free_all();
 
   // Free all buffers.  Reset 'autochdir' to avoid accessing things that
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index fcd428ba1b..16c81307ce 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -66,6 +66,7 @@
 #include <string.h>
 
 #include "nvim/api/private/helpers.h"
+#include "nvim/api/extmark.h"
 #include "nvim/api/vim.h"
 #include "nvim/arabic.h"
 #include "nvim/ascii.h"