Merge remote-tracking branch 'upstream/master' into libcallnr

1 files changed, 1006 insertions, 0 deletions

diff --git a/src/nvim/lua/treesitter.c b/src/nvim/lua/treesitter.c
new file mode 100644
index 0000000000..138031237e
--- /dev/null
+++ b/src/nvim/lua/treesitter.c
@@ -0,0 +1,1006 @@
+// 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
+
+// lua bindings for tree-sitter.
+// NB: this file mostly contains a generic lua interface for tree-sitter
+// trees and nodes, and could be broken out as a reusable lua package
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+#include <assert.h>
+
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+#include "tree_sitter/api.h"
+
+#include "nvim/lua/treesitter.h"
+#include "nvim/api/private/handle.h"
+#include "nvim/memline.h"
+#include "nvim/buffer.h"
+
+typedef struct {
+  TSParser *parser;
+  TSTree *tree;  // internal tree, used for editing/reparsing
+} TSLua_parser;
+
+typedef struct {
+  TSQueryCursor *cursor;
+  int predicated_match;
+} TSLua_cursor;
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "lua/treesitter.c.generated.h"
+#endif
+
+static struct luaL_Reg parser_meta[] = {
+  { "__gc", parser_gc },
+  { "__tostring", parser_tostring },
+  { "parse_buf", parser_parse_buf },
+  { "edit", parser_edit },
+  { "tree", parser_tree },
+  { "set_included_ranges", parser_set_ranges },
+  { NULL, NULL }
+};
+
+static struct luaL_Reg tree_meta[] = {
+  { "__gc", tree_gc },
+  { "__tostring", tree_tostring },
+  { "root", tree_root },
+  { NULL, NULL }
+};
+
+static struct luaL_Reg node_meta[] = {
+  { "__tostring", node_tostring },
+  { "__eq", node_eq },
+  { "__len", node_child_count },
+  { "range", node_range },
+  { "start", node_start },
+  { "end_", node_end },
+  { "type", node_type },
+  { "symbol", node_symbol },
+  { "named", node_named },
+  { "missing", node_missing },
+  { "has_error", node_has_error },
+  { "sexpr", node_sexpr },
+  { "child_count", node_child_count },
+  { "named_child_count", node_named_child_count },
+  { "child", node_child },
+  { "named_child", node_named_child },
+  { "descendant_for_range", node_descendant_for_range },
+  { "named_descendant_for_range", node_named_descendant_for_range },
+  { "parent", node_parent },
+  { "_rawquery", node_rawquery },
+  { NULL, NULL }
+};
+
+static struct luaL_Reg query_meta[] = {
+  { "__gc", query_gc },
+  { "__tostring", query_tostring },
+  { "inspect", query_inspect },
+  { NULL, NULL }
+};
+
+// cursor is not exposed, but still needs garbage collection
+static struct luaL_Reg querycursor_meta[] = {
+  { "__gc", querycursor_gc },
+  { NULL, NULL }
+};
+
+static PMap(cstr_t) *langs;
+
+static void build_meta(lua_State *L, const char *tname, const luaL_Reg *meta)
+{
+  if (luaL_newmetatable(L, tname)) {  // [meta]
+    luaL_register(L, NULL, meta);
+
+    lua_pushvalue(L, -1);  // [meta, meta]
+    lua_setfield(L, -2, "__index");  // [meta]
+  }
+  lua_pop(L, 1);  // [] (don't use it now)
+}
+
+/// init the tslua library
+///
+/// all global state is stored in the regirstry of the lua_State
+void tslua_init(lua_State *L)
+{
+  langs = pmap_new(cstr_t)();
+
+  // type metatables
+  build_meta(L, "treesitter_parser", parser_meta);
+  build_meta(L, "treesitter_tree", tree_meta);
+  build_meta(L, "treesitter_node", node_meta);
+  build_meta(L, "treesitter_query", query_meta);
+  build_meta(L, "treesitter_querycursor", querycursor_meta);
+}
+
+int tslua_has_language(lua_State *L)
+{
+  const char *lang_name = luaL_checkstring(L, 1);
+  lua_pushboolean(L, pmap_has(cstr_t)(langs, lang_name));
+  return 1;
+}
+
+int tslua_add_language(lua_State *L)
+{
+  if (lua_gettop(L) < 2 || !lua_isstring(L, 1) || !lua_isstring(L, 2)) {
+    return luaL_error(L, "string expected");
+  }
+
+  const char *path = lua_tostring(L, 1);
+  const char *lang_name = lua_tostring(L, 2);
+
+  if (pmap_has(cstr_t)(langs, lang_name)) {
+    return 0;
+  }
+
+#define BUFSIZE 128
+  char symbol_buf[BUFSIZE];
+  snprintf(symbol_buf, BUFSIZE, "tree_sitter_%s", lang_name);
+#undef BUFSIZE
+
+  uv_lib_t lib;
+  if (uv_dlopen(path, &lib)) {
+    snprintf((char *)IObuff, IOSIZE, "Failed to load parser: uv_dlopen: %s",
+             uv_dlerror(&lib));
+    uv_dlclose(&lib);
+    lua_pushstring(L, (char *)IObuff);
+    return lua_error(L);
+  }
+
+  TSLanguage *(*lang_parser)(void);
+  if (uv_dlsym(&lib, symbol_buf, (void **)&lang_parser)) {
+    snprintf((char *)IObuff, IOSIZE, "Failed to load parser: uv_dlsym: %s",
+             uv_dlerror(&lib));
+    uv_dlclose(&lib);
+    lua_pushstring(L, (char *)IObuff);
+    return lua_error(L);
+  }
+
+  TSLanguage *lang = lang_parser();
+  if (lang == NULL) {
+    return luaL_error(L, "Failed to load parser: internal error");
+  }
+
+  pmap_put(cstr_t)(langs, xstrdup(lang_name), lang);
+
+  lua_pushboolean(L, true);
+  return 1;
+}
+
+int tslua_inspect_lang(lua_State *L)
+{
+  if (lua_gettop(L) < 1 || !lua_isstring(L, 1)) {
+    return luaL_error(L, "string expected");
+  }
+  const char *lang_name = lua_tostring(L, 1);
+
+  TSLanguage *lang = pmap_get(cstr_t)(langs, lang_name);
+  if (!lang) {
+    return luaL_error(L, "no such language: %s", lang_name);
+  }
+
+  lua_createtable(L, 0, 2);  // [retval]
+
+  size_t nsymbols = (size_t)ts_language_symbol_count(lang);
+
+  lua_createtable(L, nsymbols-1, 1);  // [retval, symbols]
+  for (size_t i = 0; i < nsymbols; i++) {
+    TSSymbolType t = ts_language_symbol_type(lang, i);
+    if (t == TSSymbolTypeAuxiliary) {
+      // not used by the API
+      continue;
+    }
+    lua_createtable(L, 2, 0);  // [retval, symbols, elem]
+    lua_pushstring(L, ts_language_symbol_name(lang, i));
+    lua_rawseti(L, -2, 1);
+    lua_pushboolean(L, t == TSSymbolTypeRegular);
+    lua_rawseti(L, -2, 2);  // [retval, symbols, elem]
+    lua_rawseti(L, -2, i);  // [retval, symbols]
+  }
+
+  lua_setfield(L, -2, "symbols");  // [retval]
+
+  size_t nfields = (size_t)ts_language_field_count(lang);
+  lua_createtable(L, nfields-1, 1);  // [retval, fields]
+  for (size_t i = 0; i < nfields; i++) {
+    lua_pushstring(L, ts_language_field_name_for_id(lang, i));
+    lua_rawseti(L, -2, i);  // [retval, fields]
+  }
+
+  lua_setfield(L, -2, "fields");  // [retval]
+  return 1;
+}
+
+int tslua_push_parser(lua_State *L)
+{
+  // Gather language
+  if (lua_gettop(L) < 1 || !lua_isstring(L, 1)) {
+    return luaL_error(L, "string expected");
+  }
+  const char *lang_name = lua_tostring(L, 1);
+  TSLanguage *lang = pmap_get(cstr_t)(langs, lang_name);
+  if (!lang) {
+    return luaL_error(L, "no such language: %s", lang_name);
+  }
+
+  TSParser *parser = ts_parser_new();
+  ts_parser_set_language(parser, lang);
+  TSLua_parser *p = lua_newuserdata(L, sizeof(TSLua_parser));  // [udata]
+  p->parser = parser;
+  p->tree = NULL;
+
+  lua_getfield(L, LUA_REGISTRYINDEX, "treesitter_parser");  // [udata, meta]
+  lua_setmetatable(L, -2);  // [udata]
+  return 1;
+}
+
+static TSLua_parser *parser_check(lua_State *L)
+{
+  return luaL_checkudata(L, 1, "treesitter_parser");
+}
+
+static int parser_gc(lua_State *L)
+{
+  TSLua_parser *p = parser_check(L);
+  if (!p) {
+    return 0;
+  }
+
+  ts_parser_delete(p->parser);
+  if (p->tree) {
+    ts_tree_delete(p->tree);
+  }
+
+  return 0;
+}
+
+static int parser_tostring(lua_State *L)
+{
+  lua_pushstring(L, "<parser>");
+  return 1;
+}
+
+static const char *input_cb(void *payload, uint32_t byte_index,
+                            TSPoint position, uint32_t *bytes_read)
+{
+  buf_T *bp  = payload;
+#define BUFSIZE 256
+  static char buf[BUFSIZE];
+
+  if ((linenr_T)position.row >= bp->b_ml.ml_line_count) {
+    *bytes_read = 0;
+    return "";
+  }
+  char_u *line = ml_get_buf(bp, position.row+1, false);
+  size_t len = STRLEN(line);
+
+  if (position.column > len) {
+    *bytes_read = 0;
+  } else {
+    size_t tocopy = MIN(len-position.column, BUFSIZE);
+
+    memcpy(buf, line+position.column, tocopy);
+    // Translate embedded \n to NUL
+    memchrsub(buf, '\n', '\0', tocopy);
+    *bytes_read = (uint32_t)tocopy;
+    if (tocopy < BUFSIZE) {
+      // now add the final \n. If it didn't fit, input_cb will be called again
+      // on the same line with advanced column.
+      buf[tocopy] = '\n';
+      (*bytes_read)++;
+    }
+  }
+  return buf;
+#undef BUFSIZE
+}
+
+static int parser_parse_buf(lua_State *L)
+{
+  TSLua_parser *p = parser_check(L);
+  if (!p) {
+    return 0;
+  }
+
+  long bufnr = lua_tointeger(L, 2);
+  buf_T *buf = handle_get_buffer(bufnr);
+
+  if (!buf) {
+    return luaL_error(L, "invalid buffer handle: %d", bufnr);
+  }
+
+  TSInput input = { (void *)buf, input_cb, TSInputEncodingUTF8 };
+  TSTree *new_tree = ts_parser_parse(p->parser, p->tree, input);
+
+  uint32_t n_ranges = 0;
+  TSRange *changed = p->tree ? ts_tree_get_changed_ranges(p->tree, new_tree,
+                                                          &n_ranges) : NULL;
+  if (p->tree) {
+    ts_tree_delete(p->tree);
+  }
+  p->tree = new_tree;
+
+  tslua_push_tree(L, p->tree);
+
+  lua_createtable(L, n_ranges, 0);
+  for (size_t i = 0; i < n_ranges; i++) {
+    lua_createtable(L, 4, 0);
+    lua_pushinteger(L, changed[i].start_point.row);
+    lua_rawseti(L, -2, 1);
+    lua_pushinteger(L, changed[i].start_point.column);
+    lua_rawseti(L, -2, 2);
+    lua_pushinteger(L, changed[i].end_point.row);
+    lua_rawseti(L, -2, 3);
+    lua_pushinteger(L, changed[i].end_point.column);
+    lua_rawseti(L, -2, 4);
+
+    lua_rawseti(L, -2, i+1);
+  }
+  xfree(changed);
+  return 2;
+}
+
+static int parser_tree(lua_State *L)
+{
+  TSLua_parser *p = parser_check(L);
+  if (!p) {
+    return 0;
+  }
+
+  tslua_push_tree(L, p->tree);
+  return 1;
+}
+
+static int parser_edit(lua_State *L)
+{
+  if (lua_gettop(L) < 10) {
+    lua_pushstring(L, "not enough args to parser:edit()");
+    return lua_error(L);
+  }
+
+  TSLua_parser *p = parser_check(L);
+  if (!p) {
+    return 0;
+  }
+
+  if (!p->tree) {
+    return 0;
+  }
+
+  long start_byte = lua_tointeger(L, 2);
+  long old_end_byte = lua_tointeger(L, 3);
+  long new_end_byte = lua_tointeger(L, 4);
+  TSPoint start_point = { lua_tointeger(L, 5), lua_tointeger(L, 6) };
+  TSPoint old_end_point = { lua_tointeger(L, 7), lua_tointeger(L, 8) };
+  TSPoint new_end_point = { lua_tointeger(L, 9), lua_tointeger(L, 10) };
+
+  TSInputEdit edit = { start_byte, old_end_byte, new_end_byte,
+                       start_point, old_end_point, new_end_point };
+
+  ts_tree_edit(p->tree, &edit);
+
+  return 0;
+}
+
+static int parser_set_ranges(lua_State *L)
+{
+  if (lua_gettop(L) < 2) {
+    return luaL_error(
+        L,
+        "not enough args to parser:set_included_ranges()");
+  }
+
+  TSLua_parser *p = parser_check(L);
+  if (!p || !p->tree) {
+    return 0;
+  }
+
+  if (!lua_istable(L, 2)) {
+    return luaL_error(
+        L,
+        "argument for parser:set_included_ranges() should be a table.");
+  }
+
+  size_t tbl_len = lua_objlen(L, 2);
+  TSRange *ranges = xmalloc(sizeof(TSRange) * tbl_len);
+
+
+  // [ parser, ranges ]
+  for (size_t index = 0; index < tbl_len; index++) {
+    lua_rawgeti(L, 2, index + 1);  // [ parser, ranges, range ]
+
+    TSNode node;
+    if (!node_check(L, -1, &node)) {
+      xfree(ranges);
+      return luaL_error(
+          L,
+          "ranges should be tables of nodes.");
+    }
+    lua_pop(L, 1);  // [ parser, ranges ]
+
+    ranges[index] = (TSRange) {
+      .start_point = ts_node_start_point(node),
+      .end_point = ts_node_end_point(node),
+      .start_byte = ts_node_start_byte(node),
+      .end_byte = ts_node_end_byte(node)
+    };
+  }
+
+  // This memcpies ranges, thus we can free it afterwards
+  ts_parser_set_included_ranges(p->parser, ranges, tbl_len);
+  xfree(ranges);
+
+  return 0;
+}
+
+
+// Tree methods
+
+/// push tree interface on lua stack.
+///
+/// This makes a copy of the tree, so ownership of the argument is unaffected.
+void tslua_push_tree(lua_State *L, TSTree *tree)
+{
+  if (tree == NULL) {
+    lua_pushnil(L);
+    return;
+  }
+  TSTree **ud = lua_newuserdata(L, sizeof(TSTree *));  // [udata]
+  *ud = ts_tree_copy(tree);
+  lua_getfield(L, LUA_REGISTRYINDEX, "treesitter_tree");  // [udata, meta]
+  lua_setmetatable(L, -2);  // [udata]
+
+  // table used for node wrappers to keep a reference to tree wrapper
+  // NB: in lua 5.3 the uservalue for the node could just be the tree, but
+  // in lua 5.1 the uservalue (fenv) must be a table.
+  lua_createtable(L, 1, 0);  // [udata, reftable]
+  lua_pushvalue(L, -2);  // [udata, reftable, udata]
+  lua_rawseti(L, -2, 1);  // [udata, reftable]
+  lua_setfenv(L, -2);  // [udata]
+}
+
+static TSTree *tree_check(lua_State *L)
+{
+  TSTree **ud = luaL_checkudata(L, 1, "treesitter_tree");
+  return *ud;
+}
+
+static int tree_gc(lua_State *L)
+{
+  TSTree *tree = tree_check(L);
+  if (!tree) {
+    return 0;
+  }
+
+  ts_tree_delete(tree);
+  return 0;
+}
+
+static int tree_tostring(lua_State *L)
+{
+  lua_pushstring(L, "<tree>");
+  return 1;
+}
+
+static int tree_root(lua_State *L)
+{
+  TSTree *tree = tree_check(L);
+  if (!tree) {
+    return 0;
+  }
+  TSNode root = ts_tree_root_node(tree);
+  push_node(L, root, 1);
+  return 1;
+}
+
+// Node methods
+
+/// push node interface on lua stack
+///
+/// top of stack must either be the tree this node belongs to or another node
+/// of the same tree! This value is not popped. Can only be called inside a
+/// cfunction with the tslua environment.
+static void push_node(lua_State *L, TSNode node, int uindex)
+{
+  assert(uindex > 0 || uindex < -LUA_MINSTACK);
+  if (ts_node_is_null(node)) {
+    lua_pushnil(L);  // [nil]
+    return;
+  }
+  TSNode *ud = lua_newuserdata(L, sizeof(TSNode));  // [udata]
+  *ud = node;
+  lua_getfield(L, LUA_REGISTRYINDEX, "treesitter_node");  // [udata, meta]
+  lua_setmetatable(L, -2);  // [udata]
+  lua_getfenv(L, uindex);  // [udata, reftable]
+  lua_setfenv(L, -2);  // [udata]
+}
+
+static bool node_check(lua_State *L, int index, TSNode *res)
+{
+  TSNode *ud = luaL_checkudata(L, index, "treesitter_node");
+  if (ud) {
+    *res = *ud;
+    return true;
+  }
+  return false;
+}
+
+
+static int node_tostring(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  lua_pushstring(L, "<node ");
+  lua_pushstring(L, ts_node_type(node));
+  lua_pushstring(L, ">");
+  lua_concat(L, 3);
+  return 1;
+}
+
+static int node_eq(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  // This should only be called if both x and y in "x == y" has the
+  // treesitter_node metatable. So it is ok to error out otherwise.
+  TSNode *ud = luaL_checkudata(L, 2, "treesitter_node");
+  if (!ud) {
+    return 0;
+  }
+  TSNode node2 = *ud;
+  lua_pushboolean(L, ts_node_eq(node, node2));
+  return 1;
+}
+
+static int node_range(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSPoint start = ts_node_start_point(node);
+  TSPoint end = ts_node_end_point(node);
+  lua_pushnumber(L, start.row);
+  lua_pushnumber(L, start.column);
+  lua_pushnumber(L, end.row);
+  lua_pushnumber(L, end.column);
+  return 4;
+}
+
+static int node_start(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSPoint start = ts_node_start_point(node);
+  uint32_t start_byte = ts_node_start_byte(node);
+  lua_pushnumber(L, start.row);
+  lua_pushnumber(L, start.column);
+  lua_pushnumber(L, start_byte);
+  return 3;
+}
+
+static int node_end(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSPoint end = ts_node_end_point(node);
+  uint32_t end_byte = ts_node_end_byte(node);
+  lua_pushnumber(L, end.row);
+  lua_pushnumber(L, end.column);
+  lua_pushnumber(L, end_byte);
+  return 3;
+}
+
+static int node_child_count(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  uint32_t count = ts_node_child_count(node);
+  lua_pushnumber(L, count);
+  return 1;
+}
+
+static int node_named_child_count(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  uint32_t count = ts_node_named_child_count(node);
+  lua_pushnumber(L, count);
+  return 1;
+}
+
+static int node_type(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  lua_pushstring(L, ts_node_type(node));
+  return 1;
+}
+
+static int node_symbol(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSSymbol symbol = ts_node_symbol(node);
+  lua_pushnumber(L, symbol);
+  return 1;
+}
+
+static int node_named(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  lua_pushboolean(L, ts_node_is_named(node));
+  return 1;
+}
+
+static int node_sexpr(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  char *allocated = ts_node_string(node);
+  lua_pushstring(L, allocated);
+  xfree(allocated);
+  return 1;
+}
+
+static int node_missing(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  lua_pushboolean(L, ts_node_is_missing(node));
+  return 1;
+}
+
+static int node_has_error(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  lua_pushboolean(L, ts_node_has_error(node));
+  return 1;
+}
+
+static int node_child(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  long num = lua_tointeger(L, 2);
+  TSNode child = ts_node_child(node, (uint32_t)num);
+
+  push_node(L, child, 1);
+  return 1;
+}
+
+static int node_named_child(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  long num = lua_tointeger(L, 2);
+  TSNode child = ts_node_named_child(node, (uint32_t)num);
+
+  push_node(L, child, 1);
+  return 1;
+}
+
+static int node_descendant_for_range(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSPoint start = { (uint32_t)lua_tointeger(L, 2),
+                   (uint32_t)lua_tointeger(L, 3) };
+  TSPoint end = { (uint32_t)lua_tointeger(L, 4),
+                 (uint32_t)lua_tointeger(L, 5) };
+  TSNode child = ts_node_descendant_for_point_range(node, start, end);
+
+  push_node(L, child, 1);
+  return 1;
+}
+
+static int node_named_descendant_for_range(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSPoint start = { (uint32_t)lua_tointeger(L, 2),
+                   (uint32_t)lua_tointeger(L, 3) };
+  TSPoint end = { (uint32_t)lua_tointeger(L, 4),
+                 (uint32_t)lua_tointeger(L, 5) };
+  TSNode child = ts_node_named_descendant_for_point_range(node, start, end);
+
+  push_node(L, child, 1);
+  return 1;
+}
+
+static int node_parent(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSNode parent = ts_node_parent(node);
+  push_node(L, parent, 1);
+  return 1;
+}
+
+/// assumes the match table being on top of the stack
+static void set_match(lua_State *L, TSQueryMatch *match, int nodeidx)
+{
+  for (int i = 0; i < match->capture_count; i++) {
+    push_node(L, match->captures[i].node, nodeidx);
+    lua_rawseti(L, -2, match->captures[i].index+1);
+  }
+}
+
+static int query_next_match(lua_State *L)
+{
+  TSLua_cursor *ud = lua_touserdata(L, lua_upvalueindex(1));
+  TSQueryCursor *cursor = ud->cursor;
+
+  TSQuery *query = query_check(L, lua_upvalueindex(3));
+  TSQueryMatch match;
+  if (ts_query_cursor_next_match(cursor, &match)) {
+    lua_pushinteger(L, match.pattern_index+1);  // [index]
+    lua_createtable(L, ts_query_capture_count(query), 2);  // [index, match]
+    set_match(L, &match, lua_upvalueindex(2));
+    return 2;
+  }
+  return 0;
+}
+
+
+static int query_next_capture(lua_State *L)
+{
+  TSLua_cursor *ud = lua_touserdata(L, lua_upvalueindex(1));
+  TSQueryCursor *cursor = ud->cursor;
+
+  TSQuery *query = query_check(L, lua_upvalueindex(3));
+
+  if (ud->predicated_match > -1) {
+    lua_getfield(L, lua_upvalueindex(4), "active");
+    bool active = lua_toboolean(L, -1);
+    lua_pop(L, 1);
+    if (!active) {
+      ts_query_cursor_remove_match(cursor, ud->predicated_match);
+    }
+    ud->predicated_match = -1;
+  }
+
+  TSQueryMatch match;
+  uint32_t capture_index;
+  if (ts_query_cursor_next_capture(cursor, &match, &capture_index)) {
+    TSQueryCapture capture = match.captures[capture_index];
+
+    lua_pushinteger(L, capture.index+1);  // [index]
+    push_node(L, capture.node, lua_upvalueindex(2));  // [index, node]
+
+    uint32_t n_pred;
+    ts_query_predicates_for_pattern(query, match.pattern_index, &n_pred);
+    if (n_pred > 0 && capture_index == 0) {
+      lua_pushvalue(L, lua_upvalueindex(4));  // [index, node, match]
+      set_match(L, &match, lua_upvalueindex(2));
+      lua_pushinteger(L, match.pattern_index+1);
+      lua_setfield(L, -2, "pattern");
+
+      if (match.capture_count > 1) {
+        ud->predicated_match = match.id;
+        lua_pushboolean(L, false);
+        lua_setfield(L, -2, "active");
+      }
+      return 3;
+    }
+    return 2;
+  }
+  return 0;
+}
+
+static int node_rawquery(lua_State *L)
+{
+  TSNode node;
+  if (!node_check(L, 1, &node)) {
+    return 0;
+  }
+  TSQuery *query = query_check(L, 2);
+  // TODO(bfredl): these are expensive allegedly,
+  // use a reuse list later on?
+  TSQueryCursor *cursor = ts_query_cursor_new();
+  ts_query_cursor_exec(cursor, query, node);
+
+  bool captures = lua_toboolean(L, 3);
+
+  if (lua_gettop(L) >= 4) {
+    int start = luaL_checkinteger(L, 4);
+    int end = lua_gettop(L) >= 5 ? luaL_checkinteger(L, 5) : MAXLNUM;
+    ts_query_cursor_set_point_range(cursor,
+                                    (TSPoint){ start, 0 }, (TSPoint){ end, 0 });
+  }
+
+  TSLua_cursor *ud = lua_newuserdata(L, sizeof(*ud));  // [udata]
+  ud->cursor = cursor;
+  ud->predicated_match = -1;
+
+  lua_getfield(L, LUA_REGISTRYINDEX, "treesitter_querycursor");
+  lua_setmetatable(L, -2);  // [udata]
+  lua_pushvalue(L, 1);  // [udata, node]
+
+  // include query separately, as to keep a ref to it for gc
+  lua_pushvalue(L, 2);  // [udata, node, query]
+
+  if (captures) {
+    // placeholder for match state
+    lua_createtable(L, ts_query_capture_count(query), 2);  // [u, n, q, match]
+    lua_pushcclosure(L, query_next_capture, 4);  // [closure]
+  } else {
+    lua_pushcclosure(L, query_next_match, 3);  // [closure]
+  }
+
+  return 1;
+}
+
+static int querycursor_gc(lua_State *L)
+{
+  TSLua_cursor *ud = luaL_checkudata(L, 1, "treesitter_querycursor");
+  ts_query_cursor_delete(ud->cursor);
+  return 0;
+}
+
+// Query methods
+
+int ts_lua_parse_query(lua_State *L)
+{
+  if (lua_gettop(L) < 2 || !lua_isstring(L, 1) || !lua_isstring(L, 2)) {
+    return luaL_error(L, "string expected");
+  }
+
+  const char *lang_name = lua_tostring(L, 1);
+  TSLanguage *lang = pmap_get(cstr_t)(langs, lang_name);
+  if (!lang) {
+    return luaL_error(L, "no such language: %s", lang_name);
+  }
+
+  size_t len;
+  const char *src = lua_tolstring(L, 2, &len);
+
+  uint32_t error_offset;
+  TSQueryError error_type;
+  TSQuery *query = ts_query_new(lang, src, len, &error_offset, &error_type);
+
+  if (!query) {
+    return luaL_error(L, "query: %s at position %d",
+                      query_err_string(error_type), (int)error_offset);
+  }
+
+  TSQuery **ud = lua_newuserdata(L, sizeof(TSQuery *));  // [udata]
+  *ud = query;
+  lua_getfield(L, LUA_REGISTRYINDEX, "treesitter_query");  // [udata, meta]
+  lua_setmetatable(L, -2);  // [udata]
+  return 1;
+}
+
+
+static const char *query_err_string(TSQueryError err) {
+  switch (err) {
+    case TSQueryErrorSyntax: return "invalid syntax";
+    case TSQueryErrorNodeType: return "invalid node type";
+    case TSQueryErrorField: return "invalid field";
+    case TSQueryErrorCapture: return "invalid capture";
+    default: return "error";
+  }
+}
+
+static TSQuery *query_check(lua_State *L, int index)
+{
+  TSQuery **ud = luaL_checkudata(L, index, "treesitter_query");
+  return *ud;
+}
+
+static int query_gc(lua_State *L)
+{
+  TSQuery *query = query_check(L, 1);
+  if (!query) {
+    return 0;
+  }
+
+  ts_query_delete(query);
+  return 0;
+}
+
+static int query_tostring(lua_State *L)
+{
+  lua_pushstring(L, "<query>");
+  return 1;
+}
+
+static int query_inspect(lua_State *L)
+{
+  TSQuery *query = query_check(L, 1);
+  if (!query) {
+    return 0;
+  }
+
+  uint32_t n_pat = ts_query_pattern_count(query);
+  lua_createtable(L, 0, 2);  // [retval]
+  lua_createtable(L, n_pat, 1);  // [retval, patterns]
+  for (size_t i = 0; i < n_pat; i++) {
+    uint32_t len;
+    const TSQueryPredicateStep *step = ts_query_predicates_for_pattern(query,
+                                                                       i, &len);
+    if (len == 0) {
+      continue;
+    }
+    lua_createtable(L, len/4, 1);  // [retval, patterns, pat]
+    lua_createtable(L, 3, 0);  // [retval, patterns, pat, pred]
+    int nextpred = 1;
+    int nextitem = 1;
+    for (size_t k = 0; k < len; k++) {
+      if (step[k].type == TSQueryPredicateStepTypeDone) {
+        lua_rawseti(L, -2, nextpred++);  // [retval, patterns, pat]
+        lua_createtable(L, 3, 0);  // [retval, patterns, pat, pred]
+        nextitem = 1;
+        continue;
+      }
+
+      if (step[k].type == TSQueryPredicateStepTypeString) {
+        uint32_t strlen;
+        const char *str = ts_query_string_value_for_id(query, step[k].value_id,
+                                                       &strlen);
+        lua_pushlstring(L, str, strlen);  // [retval, patterns, pat, pred, item]
+      } else if (step[k].type == TSQueryPredicateStepTypeCapture) {
+        lua_pushnumber(L, step[k].value_id+1);  // [..., pat, pred, item]
+      } else {
+        abort();
+      }
+      lua_rawseti(L, -2, nextitem++);  // [retval, patterns, pat, pred]
+    }
+    // last predicate should have ended with TypeDone
+    lua_pop(L, 1);  // [retval, patters, pat]
+    lua_rawseti(L, -2, i+1);  // [retval, patterns]
+  }
+  lua_setfield(L, -2, "patterns");  // [retval]
+
+  uint32_t n_captures = ts_query_capture_count(query);
+  lua_createtable(L, n_captures, 0);  // [retval, captures]
+  for (size_t i = 0; i < n_captures; i++) {
+    uint32_t strlen;
+    const char *str = ts_query_capture_name_for_id(query, i, &strlen);
+    lua_pushlstring(L, str, strlen);  // [retval, captures, capture]
+    lua_rawseti(L, -2, i+1);
+  }
+  lua_setfield(L, -2, "captures");  // [retval]
+
+  return 1;
+}