diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 65e051d4..a4b3d145 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -52,6 +52,9 @@ jobs:
           toolchain: stable
           profile: minimal
 
+      - name: Check Rust code formatting
+        run: cargo fmt -- --check
+
       - name: Install emscripten
         uses: mymindstorm/setup-emsdk@v7
         with:
diff --git a/Cargo.lock b/Cargo.lock
index 26bfdb1a..f735619c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -634,7 +634,7 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tree-sitter"
-version = "0.19.4"
+version = "0.19.5"
 dependencies = [
  "cc",
  "lazy_static",
@@ -644,7 +644,7 @@ dependencies = [
 
 [[package]]
 name = "tree-sitter-cli"
-version = "0.19.4"
+version = "0.19.5"
 dependencies = [
  "ansi_term 0.12.1",
  "atty",
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index a1884d2c..693ac817 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "tree-sitter-cli"
 description = "CLI tool for developing, testing, and using Tree-sitter parsers"
-version = "0.19.4"
+version = "0.19.5"
 authors = ["Max Brunsfeld <maxbrunsfeld@gmail.com>"]
 edition = "2018"
 license = "MIT"
diff --git a/cli/npm/package.json b/cli/npm/package.json
index 1d0fe136..2c5e364a 100644
--- a/cli/npm/package.json
+++ b/cli/npm/package.json
@@ -1,6 +1,6 @@
 {
   "name": "tree-sitter-cli",
-  "version": "0.19.4",
+  "version": "0.19.5",
   "author": "Max Brunsfeld",
   "license": "MIT",
   "repository": {
diff --git a/cli/src/generate/binding_files.rs b/cli/src/generate/binding_files.rs
index ed56fcde..0a55e35a 100644
--- a/cli/src/generate/binding_files.rs
+++ b/cli/src/generate/binding_files.rs
@@ -95,7 +95,11 @@ pub fn generate_binding_files(repo_path: &Path, language_name: &str) -> Result<(
                 write_file(&package_json_path, package_json_str)?;
             }
         } else {
-            generate_file(&package_json_path, PACKAGE_JSON_TEMPLATE, dashed_language_name)?;
+            generate_file(
+                &package_json_path,
+                PACKAGE_JSON_TEMPLATE,
+                dashed_language_name,
+            )?;
         }
 
         // Remove files from old node binding paths.
diff --git a/cli/src/generate/render.rs b/cli/src/generate/render.rs
index 9d22f4a3..78a07a22 100644
--- a/cli/src/generate/render.rs
+++ b/cli/src/generate/render.rs
@@ -355,7 +355,7 @@ impl Generator {
     }
 
     fn add_symbol_names_list(&mut self) {
-        add_line!(self, "static const char *ts_symbol_names[] = {{");
+        add_line!(self, "static const char * const ts_symbol_names[] = {{");
         indent!(self);
         for symbol in self.parse_table.symbols.iter() {
             let name = self.sanitize_string(
@@ -417,7 +417,7 @@ impl Generator {
     }
 
     fn add_field_name_names_list(&mut self) {
-        add_line!(self, "static const char *ts_field_names[] = {{");
+        add_line!(self, "static const char * const ts_field_names[] = {{");
         indent!(self);
         add_line!(self, "[0] = NULL,");
         for field_name in &self.field_names {
@@ -543,7 +543,10 @@ impl Generator {
         let mut alias_ids_by_symbol = alias_ids_by_symbol.iter().collect::<Vec<_>>();
         alias_ids_by_symbol.sort_unstable_by_key(|e| e.0);
 
-        add_line!(self, "static const uint16_t ts_non_terminal_alias_map[] = {{");
+        add_line!(
+            self,
+            "static const uint16_t ts_non_terminal_alias_map[] = {{"
+        );
         indent!(self);
         for (symbol, alias_ids) in alias_ids_by_symbol {
             let symbol_id = &self.symbol_ids[symbol];
@@ -962,7 +965,10 @@ impl Generator {
     }
 
     fn add_lex_modes_list(&mut self) {
-        add_line!(self, "static const TSLexMode ts_lex_modes[STATE_COUNT] = {{");
+        add_line!(
+            self,
+            "static const TSLexMode ts_lex_modes[STATE_COUNT] = {{"
+        );
         indent!(self);
         for (i, state) in self.parse_table.states.iter().enumerate() {
             if state.is_end_of_non_terminal_extra() {
@@ -1200,7 +1206,10 @@ impl Generator {
             add_line!(self, "}};");
             add_line!(self, "");
 
-            add_line!(self, "static const uint32_t ts_small_parse_table_map[] = {{");
+            add_line!(
+                self,
+                "static const uint32_t ts_small_parse_table_map[] = {{"
+            );
             indent!(self);
             for i in self.large_state_count..self.parse_table.states.len() {
                 add_line!(
@@ -1219,7 +1228,10 @@ impl Generator {
     }
 
     fn add_parse_action_list(&mut self, parse_table_entries: Vec<(usize, ParseTableEntry)>) {
-        add_line!(self, "static const TSParseActionEntry ts_parse_actions[] = {{");
+        add_line!(
+            self,
+            "static const TSParseActionEntry ts_parse_actions[] = {{"
+        );
         indent!(self);
         for (i, entry) in parse_table_entries {
             add!(
@@ -1334,14 +1346,8 @@ impl Generator {
         // Parse table
         add_line!(self, ".parse_table = &ts_parse_table[0][0],");
         if self.large_state_count < self.parse_table.states.len() {
-            add_line!(
-                self,
-                ".small_parse_table = ts_small_parse_table,"
-            );
-            add_line!(
-                self,
-                ".small_parse_table_map = ts_small_parse_table_map,"
-            );
+            add_line!(self, ".small_parse_table = ts_small_parse_table,");
+            add_line!(self, ".small_parse_table_map = ts_small_parse_table_map,");
         }
         add_line!(self, ".parse_actions = ts_parse_actions,");
 
@@ -1349,23 +1355,14 @@ impl Generator {
         add_line!(self, ".symbol_names = ts_symbol_names,");
         if !self.field_names.is_empty() {
             add_line!(self, ".field_names = ts_field_names,");
-            add_line!(
-                self,
-                ".field_map_slices = ts_field_map_slices,"
-            );
-            add_line!(
-                self,
-                ".field_map_entries = ts_field_map_entries,"
-            );
+            add_line!(self, ".field_map_slices = ts_field_map_slices,");
+            add_line!(self, ".field_map_entries = ts_field_map_entries,");
         }
         add_line!(self, ".symbol_metadata = ts_symbol_metadata,");
         add_line!(self, ".public_symbol_map = ts_symbol_map,");
         add_line!(self, ".alias_map = ts_non_terminal_alias_map,");
         if !self.parse_table.production_infos.is_empty() {
-            add_line!(
-                self,
-                ".alias_sequences = &ts_alias_sequences[0][0],"
-            );
+            add_line!(self, ".alias_sequences = &ts_alias_sequences[0][0],");
         }
 
         // Lexing
diff --git a/cli/src/main.rs b/cli/src/main.rs
index e7600b30..a2d0a7da 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -122,7 +122,12 @@ fn run() -> error::Result<()> {
                         .takes_value(true)
                         .help("Only run corpus test cases whose name includes the given string"),
                 )
-                .arg(Arg::with_name("update").long("update").short("u").help("Update all syntax trees in corpus files with current parser output"))
+                .arg(
+                    Arg::with_name("update")
+                        .long("update")
+                        .short("u")
+                        .help("Update all syntax trees in corpus files with current parser output"),
+                )
                 .arg(Arg::with_name("debug").long("debug").short("d"))
                 .arg(Arg::with_name("debug-graph").long("debug-graph").short("D")),
         )
diff --git a/cli/src/parse.rs b/cli/src/parse.rs
index 5266b19f..e843663e 100644
--- a/cli/src/parse.rs
+++ b/cli/src/parse.rs
@@ -197,7 +197,8 @@ pub fn parse_file_at_path(
                         did_visit_children = true;
                         let start = node.start_byte();
                         let end = node.end_byte();
-                        let value = std::str::from_utf8(&source_code[start..end]).expect("has a string");
+                        let value =
+                            std::str::from_utf8(&source_code[start..end]).expect("has a string");
                         write!(&mut stdout, "{}", html_escape::encode_text(value))?;
                     }
                 }
diff --git a/cli/src/tests/helpers/random.rs b/cli/src/tests/helpers/random.rs
index b0490e7e..4fc8f989 100644
--- a/cli/src/tests/helpers/random.rs
+++ b/cli/src/tests/helpers/random.rs
@@ -13,7 +13,7 @@ impl Rand {
     }
 
     pub fn unsigned(&mut self, max: usize) -> usize {
-        self.0.gen_range(0 .. max + 1)
+        self.0.gen_range(0..max + 1)
     }
 
     pub fn words(&mut self, max_count: usize) -> Vec<u8> {
diff --git a/cli/src/tests/helpers/scope_sequence.rs b/cli/src/tests/helpers/scope_sequence.rs
index 685fe91f..2f904025 100644
--- a/cli/src/tests/helpers/scope_sequence.rs
+++ b/cli/src/tests/helpers/scope_sequence.rs
@@ -47,7 +47,10 @@ impl ScopeSequence {
         if self.0.len() != text.len() {
             panic!(
                 "Inconsistent scope sequence: {:?}",
-                self.0.iter().zip(text.iter().map(|c| *c as char)).collect::<Vec<_>>()
+                self.0
+                    .iter()
+                    .zip(text.iter().map(|c| *c as char))
+                    .collect::<Vec<_>>()
             );
         }
 
diff --git a/docs/index.md b/docs/index.md
index b5538c55..a773437b 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -69,6 +69,7 @@ Parsers for these languages are in development:
 * [Go mod](https://github.com/camdencheek/tree-sitter-go-mod)
 * [Haskell](https://github.com/tree-sitter/tree-sitter-haskell)
 * [Julia](https://github.com/tree-sitter/tree-sitter-julia)
+* [Kotlin](https://github.com/fwcd/tree-sitter-kotlin)
 * [Nix](https://github.com/cstrahan/tree-sitter-nix)
 * [Perl](https://github.com/ganezdragon/tree-sitter-perl)
 * [Scala](https://github.com/tree-sitter/tree-sitter-scala)
diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index 8e6fdced..dadc0367 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "tree-sitter"
 description = "Rust bindings to the Tree-sitter parsing library"
-version = "0.19.4"
+version = "0.19.5"
 authors = ["Max Brunsfeld <maxbrunsfeld@gmail.com>"]
 edition = "2018"
 license = "MIT"
diff --git a/lib/binding_rust/lib.rs b/lib/binding_rust/lib.rs
index 7a8c7e24..22a0c2c1 100644
--- a/lib/binding_rust/lib.rs
+++ b/lib/binding_rust/lib.rs
@@ -1942,7 +1942,8 @@ impl error::Error for QueryError {}
 unsafe impl Send for Language {}
 unsafe impl Send for Parser {}
 unsafe impl Send for Query {}
-unsafe impl Send for Tree {}
 unsafe impl Send for QueryCursor {}
+unsafe impl Send for Tree {}
 unsafe impl Sync for Language {}
 unsafe impl Sync for Query {}
+unsafe impl Sync for Tree {}
diff --git a/lib/binding_web/exports.json b/lib/binding_web/exports.json
index 67787b25..01f93434 100644
--- a/lib/binding_web/exports.json
+++ b/lib/binding_web/exports.json
@@ -26,7 +26,6 @@
   "_memcpy",
   "_strlen",
   "_towupper",
-  "abort",
 
   "_ts_init",
   "_ts_language_field_count",
diff --git a/lib/binding_web/package.json b/lib/binding_web/package.json
index a3d11b55..b63a4072 100644
--- a/lib/binding_web/package.json
+++ b/lib/binding_web/package.json
@@ -1,6 +1,6 @@
 {
   "name": "web-tree-sitter",
-  "version": "0.19.3",
+  "version": "0.19.4",
   "description": "Tree-sitter bindings for the web",
   "main": "tree-sitter.js",
   "types": "tree-sitter-web.d.ts",
diff --git a/lib/include/tree_sitter/parser.h b/lib/include/tree_sitter/parser.h
index a3a87bd1..cbbc7b4e 100644
--- a/lib/include/tree_sitter/parser.h
+++ b/lib/include/tree_sitter/parser.h
@@ -102,8 +102,8 @@ struct TSLanguage {
   const uint16_t *small_parse_table;
   const uint32_t *small_parse_table_map;
   const TSParseActionEntry *parse_actions;
-  const char **symbol_names;
-  const char **field_names;
+  const char * const *symbol_names;
+  const char * const *field_names;
   const TSFieldMapSlice *field_map_slices;
   const TSFieldMapEntry *field_map_entries;
   const TSSymbolMetadata *symbol_metadata;
diff --git a/lib/src/node.c b/lib/src/node.c
index ad360cfa..156b9a18 100644
--- a/lib/src/node.c
+++ b/lib/src/node.c
@@ -150,9 +150,6 @@ static inline TSNode ts_node__child(
     while (ts_node_child_iterator_next(&iterator, &child)) {
       if (ts_node__is_relevant(child, include_anonymous)) {
         if (index == child_index) {
-          if (ts_node__is_relevant(self, true)) {
-            ts_tree_set_cached_parent(self.tree, &child, &self);
-          }
           return child;
         }
         index++;
@@ -355,7 +352,6 @@ static inline TSNode ts_node__descendant_for_byte_range(
 
       node = child;
       if (ts_node__is_relevant(node, include_anonymous)) {
-        ts_tree_set_cached_parent(self.tree, &child, &last_visible_node);
         last_visible_node = node;
       }
       did_descend = true;
@@ -395,7 +391,6 @@ static inline TSNode ts_node__descendant_for_point_range(
 
       node = child;
       if (ts_node__is_relevant(node, include_anonymous)) {
-        ts_tree_set_cached_parent(self.tree, &child, &last_visible_node);
         last_visible_node = node;
       }
       did_descend = true;
@@ -464,10 +459,7 @@ bool ts_node_has_error(TSNode self) {
 }
 
 TSNode ts_node_parent(TSNode self) {
-  TSNode node = ts_tree_get_cached_parent(self.tree, &self);
-  if (node.id) return node;
-
-  node = ts_tree_root_node(self.tree);
+  TSNode node = ts_tree_root_node(self.tree);
   uint32_t end_byte = ts_node_end_byte(self);
   if (node.id == self.id) return ts_node__null();
 
@@ -486,7 +478,6 @@ TSNode ts_node_parent(TSNode self) {
       if (iterator.position.bytes >= end_byte) {
         node = child;
         if (ts_node__is_relevant(child, true)) {
-          ts_tree_set_cached_parent(self.tree, &node, &last_visible_node);
           last_visible_node = node;
         }
         did_descend = true;
diff --git a/lib/src/tree.c b/lib/src/tree.c
index 391fa7f5..f2cc85ef 100644
--- a/lib/src/tree.c
+++ b/lib/src/tree.c
@@ -5,8 +5,6 @@
 #include "./tree_cursor.h"
 #include "./tree.h"
 
-static const unsigned PARENT_CACHE_CAPACITY = 32;
-
 TSTree *ts_tree_new(
   Subtree root, const TSLanguage *language,
   const TSRange *included_ranges, unsigned included_range_count
@@ -14,9 +12,6 @@ TSTree *ts_tree_new(
   TSTree *result = ts_malloc(sizeof(TSTree));
   result->root = root;
   result->language = language;
-  result->parent_cache = NULL;
-  result->parent_cache_start = 0;
-  result->parent_cache_size = 0;
   result->included_ranges = ts_calloc(included_range_count, sizeof(TSRange));
   memcpy(result->included_ranges, included_ranges, included_range_count * sizeof(TSRange));
   result->included_range_count = included_range_count;
@@ -35,7 +30,6 @@ void ts_tree_delete(TSTree *self) {
   ts_subtree_release(&pool, self->root);
   ts_subtree_pool_delete(&pool);
   ts_free(self->included_ranges);
-  if (self->parent_cache) ts_free(self->parent_cache);
   ts_free(self);
 }
 
@@ -78,8 +72,6 @@ void ts_tree_edit(TSTree *self, const TSInputEdit *edit) {
 
   SubtreePool pool = ts_subtree_pool_new(0);
   self->root = ts_subtree_edit(self->root, edit, &pool);
-  self->parent_cache_start = 0;
-  self->parent_cache_size = 0;
   ts_subtree_pool_delete(&pool);
 }
 
@@ -111,38 +103,3 @@ TSRange *ts_tree_get_changed_ranges(const TSTree *self, const TSTree *other, uin
 void ts_tree_print_dot_graph(const TSTree *self, FILE *file) {
   ts_subtree_print_dot_graph(self->root, self->language, file);
 }
-
-TSNode ts_tree_get_cached_parent(const TSTree *self, const TSNode *node) {
-  for (uint32_t i = 0; i < self->parent_cache_size; i++) {
-    uint32_t index = (self->parent_cache_start + i) % PARENT_CACHE_CAPACITY;
-    ParentCacheEntry *entry = &self->parent_cache[index];
-    if (entry->child == node->id) {
-      return ts_node_new(self, entry->parent, entry->position, entry->alias_symbol);
-    }
-  }
-  return ts_node_new(NULL, NULL, length_zero(), 0);
-}
-
-void ts_tree_set_cached_parent(const TSTree *_self, const TSNode *node, const TSNode *parent) {
-  TSTree *self = (TSTree *)_self;
-  if (!self->parent_cache) {
-    self->parent_cache = ts_calloc(PARENT_CACHE_CAPACITY, sizeof(ParentCacheEntry));
-  }
-
-  uint32_t index = (self->parent_cache_start + self->parent_cache_size) % PARENT_CACHE_CAPACITY;
-  self->parent_cache[index] = (ParentCacheEntry) {
-    .child = node->id,
-    .parent = (const Subtree *)parent->id,
-    .position = {
-      parent->context[0],
-      {parent->context[1], parent->context[2]}
-    },
-    .alias_symbol = parent->context[3],
-  };
-
-  if (self->parent_cache_size == PARENT_CACHE_CAPACITY) {
-    self->parent_cache_start++;
-  } else {
-    self->parent_cache_size++;
-  }
-}
diff --git a/lib/src/tree.h b/lib/src/tree.h
index 92a7e641..0334b824 100644
--- a/lib/src/tree.h
+++ b/lib/src/tree.h
@@ -15,17 +15,12 @@ typedef struct {
 struct TSTree {
   Subtree root;
   const TSLanguage *language;
-  ParentCacheEntry *parent_cache;
-  uint32_t parent_cache_start;
-  uint32_t parent_cache_size;
   TSRange *included_ranges;
   unsigned included_range_count;
 };
 
 TSTree *ts_tree_new(Subtree root, const TSLanguage *language, const TSRange *, unsigned);
 TSNode ts_node_new(const TSTree *, const Subtree *, Length, TSSymbol);
-TSNode ts_tree_get_cached_parent(const TSTree *, const TSNode *);
-void ts_tree_set_cached_parent(const TSTree *, const TSNode *, const TSNode *);
 
 #ifdef __cplusplus
 }