From 1e9e2451bef21ff705e677802d1b0980356f1f86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Linse?= <bjorn.linse@gmail.com>
Date: Fri, 7 Jun 2019 18:19:59 +0200
Subject: [PATCH] tree-sitter: objectify API

---
 runtime/lua/tree_sitter_demo.lua |  2 +-
 runtime/lua/vim/tree_sitter.lua  | 46 +++++++++++++++++++-------------
 runtime/plugin/ts_test.vim       |  3 +--
 src/nvim/lua/executor.c          | 14 +---------
 4 files changed, 30 insertions(+), 35 deletions(-)

diff --git a/runtime/lua/tree_sitter_demo.lua b/runtime/lua/tree_sitter_demo.lua
index 24a0f3d622..bbfd69109d 100644
--- a/runtime/lua/tree_sitter_demo.lua
+++ b/runtime/lua/tree_sitter_demo.lua
@@ -7,7 +7,7 @@ end
 local my_ns = __treesitter_rt_ns
 
 function ts_inspect_pos(row,col)
-  local tree = parse_tree(theparser)
+  local tree = theparser:parse_tree()
   local root = tree:root()
   local node = root:descendant_for_point_range(row,col,row,col)
   show_node(node)
diff --git a/runtime/lua/vim/tree_sitter.lua b/runtime/lua/vim/tree_sitter.lua
index a4cb3f3db6..bbc4db5f29 100644
--- a/runtime/lua/vim/tree_sitter.lua
+++ b/runtime/lua/vim/tree_sitter.lua
@@ -1,47 +1,55 @@
 local a = vim.api
 
-function parse_tree(tsstate, force)
-  if tsstate.valid and not force then
-    return tsstate.tree
+local Parser = {}
+Parser.__index = Parser
+
+function Parser:parse_tree(force)
+  if self.valid and not force then
+    return self.tree
   end
-  tsstate.tree = tsstate.parser:parse_buf(tsstate.bufnr)
-  tsstate.valid = true
-  return tsstate.tree
+  self.tree = self._parser:parse_buf(self.bufnr)
+  self.valid = true
+  return self.tree
 end
 
-local function change_cb(tsstate, ev, bufnr, tick, start_row, oldstopline, stop_row)
+local function change_cb(self, ev, bufnr, tick, start_row, oldstopline, stop_row)
   local start_byte = a.nvim_buf_get_offset(bufnr,start_row)
   -- a bit messy, should we expose edited but not reparsed tree?
   -- are multiple edits safe in general?
-  local root = tsstate.parser:tree():root()
+  local root = self._parser:tree():root()
   -- TODO: add proper lookup function!
   local inode = root:descendant_for_point_range(oldstopline+9000,0, oldstopline,0)
   if inode == nil then
     local stop_byte = a.nvim_buf_get_offset(bufnr,stop_row)
-    tsstate.parser:edit(start_byte,stop_byte,stop_byte,start_row,0,stop_row,0,stop_row,0)
+    self._parser:edit(start_byte,stop_byte,stop_byte,start_row,0,stop_row,0,stop_row,0)
   else
     local fakeoldstoprow, fakeoldstopcol, fakebyteoldstop = inode:start()
     local fake_rows = fakeoldstoprow-oldstopline
     local fakestop = stop_row+fake_rows
     local fakebytestop = a.nvim_buf_get_offset(bufnr,fakestop)+fakeoldstopcol
-    tsstate.parser:edit(start_byte,fakebyteoldstop,fakebytestop,start_row,0,fakeoldstoprow,fakeoldstopcol,fakestop,fakeoldstopcol)
+    self._parser:edit(start_byte,fakebyteoldstop,fakebytestop,start_row,0,fakeoldstoprow,fakeoldstopcol,fakestop,fakeoldstopcol)
   end
-  tsstate.valid = false
+  self.valid = false
 end
 
-function create_parser(bufnr)
+local function create_parser(bufnr)
   if bufnr == 0 then
     bufnr = a.nvim_get_current_buf()
   end
   local ft = a.nvim_buf_get_option(bufnr, "filetype")
-  local tsstate = {}
-  tsstate.bufnr = bufnr
-  tsstate.parser = vim.ts_parser(ft.."_parser.so", ft)
-  parse_tree(tsstate)
+  local self = setmetatable({bufnr=bufnr, valid=false}, Parser)
+  self._parser = vim._create_ts_parser(ft.."_parser.so", ft)
+  self:parse_tree()
   local function cb(ev, ...)
-    return change_cb(tsstate, ev, ...)
+    -- TODO: use weakref to self, so that the parser is free'd is no plugin is
+    -- using it.
+    return change_cb(self, ev, ...)
   end
-  a.nvim_buf_attach(tsstate.bufnr, false, {on_lines=cb})
-  return tsstate
+  a.nvim_buf_attach(self.bufnr, false, {on_lines=cb})
+  return self
 end
 
+-- TODO: weak table with reusable parser per buffer.
+
+return {create_parser=create_parser}
+
diff --git a/runtime/plugin/ts_test.vim b/runtime/plugin/ts_test.vim
index d048dbe7c8..76318163f6 100644
--- a/runtime/plugin/ts_test.vim
+++ b/runtime/plugin/ts_test.vim
@@ -6,9 +6,8 @@ func! TSTest()
     return
   end
   " TODO: module!
-  lua require'vim.tree_sitter'
+  lua theparser = require'vim.tree_sitter'.create_parser(0)
   lua require'tree_sitter_demo'
-  lua theparser = create_parser(vim.api.nvim_get_current_buf())
   let g:has_ts = v:true
 endfunc
 
diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index 1794cee8d8..a6447ebb2b 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -822,16 +822,6 @@ void ex_luafile(exarg_T *const eap)
   }
 }
 
-static int unsafe_ptr_to_ts_tree(lua_State *L)
-{
-  if (!lua_gettop(L)) {
-    return 0;
-  }
-  TSTree *const *ptr = lua_topointer(L,1);
-  tslua_push_tree(L, *ptr);
-  return 1;
-}
-
 static int create_tslua_parser(lua_State *L)
 {
   if (lua_gettop(L) < 2) {
@@ -867,9 +857,7 @@ static int create_tslua_parser(lua_State *L)
 static void nlua_add_treesitter(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL
 {
   tslua_init(lstate);
-  lua_pushcfunction(lstate, unsafe_ptr_to_ts_tree);
-  lua_setfield(lstate, -2, "unsafe_ts_tree");
 
   lua_pushcfunction(lstate, create_tslua_parser);
-  lua_setfield(lstate, -2, "ts_parser");
+  lua_setfield(lstate, -2, "_create_ts_parser");
 }