moonbitlang · bobzhang · May 27, 2026
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
@@ -192,7 +192,7 @@ jobs:
       - name: format diff
         run: |
           moon fmt
-          moon fmt --manifest-path src/process/test_programs/moon.mod.json
+          moon -C src/process/test_programs fmt
           git diff --exit-code
 
   moon-info:

diff --git a/examples/http_file_server/main.mbt b/examples/http_file_server/main.mbt
@@ -21,8 +21,7 @@ async fn serve_directory(
   let files = dir.read_all()
   files.sort()
   conn.send_response(200, "OK", extra_headers={ "Content-Type": "text/html" })
-  conn
-    <+
+  conn <+
     $|<!DOCTYPE html><html><head></head><body>
     $|<h1>\{path}</h1>
     $|<div style="margin: 1em; font-size: 15pt">

diff --git a/examples/http_file_server/server_wbtest.mbt b/examples/http_file_server/server_wbtest.mbt
@@ -52,8 +52,8 @@ async test "basic" {
     client_log <+ "client: GET /examples/http_file_server\n"
     client(addr, "/examples/http_file_server", client_log)
     client_log <+ "\n\n"
-    client_log <+ "client: GET /examples/moon.mod.json\n"
-    client(addr, "/examples/moon.mod.json", client_log)
+    client_log <+ "client: GET /examples/moon.mod\n"
+    client(addr, "/examples/moon.mod", client_log)
     client_log <+ "\n\n"
     let tmp_file_name = "examples/test.zip"
     let tmp_file = @fs.create(tmp_file_name, permission=0o644)
@@ -113,27 +113,34 @@ async test "basic" {
       #|<a href="/examples/http_file_server/pkg.generated.mbti">pkg.generated.mbti</a><br/>
       #|</div></body></html>
       #|
-      #|client: GET /examples/moon.mod.json
+      #|client: GET /examples/moon.mod
       #|HTTP/1.1 200 OK
       #|content-type: appliaction/octet-stream
-      #|content-length: 362
-      #|{
-      #|  "name": "moonbitlang/async_examples",
-      #|  "version": "0.3.0",
-      #|  "deps": {
-      #|    "moonbitlang/async": {
-      #|      "path": ".."
-      #|    }
-      #|  },
-      #|  "readme": "README.md",
-      #|  "repository": "https://github.com/moonbitlang/async",
-      #|  "license": "Apache-2.0",
-      #|  "keywords": [],
-      #|  "description": "Examples for `moonbitlang/async`",
-      #|  "source": ".",
-      #|  "preferred-target": "native"
+      #|content-length: 318
+      #|name = "moonbitlang/async_examples"
+      #|
+      #|version = "0.3.0"
+      #|
+      #|import {
+      #|  "moonbitlang/async@0.19.1",
       #|}
       #|
+      #|readme = "README.md"
+      #|
+      #|repository = "https://github.com/moonbitlang/async"
+      #|
+      #|license = "Apache-2.0"
+      #|
+      #|keywords = [ ]
+      #|
+      #|description = "Examples for `moonbitlang/async`"
+      #|
+      #|preferred_target = "native"
+      #|
+      #|options(
+      #|  source: ".",
+      #|)
+      #|
       #|
       #|HTTP/1.1 200 OK
       #|content-type: application/octet-stream

diff --git a/examples/moon.mod b/examples/moon.mod
@@ -0,0 +1,23 @@
+name = "moonbitlang/async_examples"
+
+version = "0.3.0"
+
+import {
+  "moonbitlang/async@0.19.1",
+}
+
+readme = "README.md"
+
+repository = "https://github.com/moonbitlang/async"
+
+license = "Apache-2.0"
+
+keywords = [ ]
+
+description = "Examples for `moonbitlang/async`"
+
+preferred_target = "native"
+
+options(
+  source: ".",
+)
diff --git a/examples/moon.mod.json b/examples/moon.mod.json
diff --git a/examples/tcp_ping_pong/deprecated.mbt b/examples/tcp_ping_pong/deprecated.mbt
@@ -17,6 +17,6 @@
 impl Show for ServerTerminate
 
 ///|
-impl Show for ServerTerminate with output(_self, logger) {
+impl Show for ServerTerminate with fn output(_self, logger) {
   logger <+ "ServerTerminate"
 }
diff --git a/examples/tcp_server_benchmark/main.mbt b/examples/tcp_server_benchmark/main.mbt
@@ -109,7 +109,7 @@ async fn main {
   let conn_duration = @string.parse_int(conn_duration_str)
   let addr = @socket.Addr::parse(addr_str)
   let rand = {
-    let seed = @buffer.new()
+    let seed = Buffer()
     let now = @env.now()
     seed
     ..write_uint64_le(now)

diff --git a/examples/udp_ping_pong/deprecated.mbt b/examples/udp_ping_pong/deprecated.mbt
@@ -17,6 +17,6 @@
 impl Show for ServerTerminate
 
 ///|
-impl Show for ServerTerminate with output(_self, logger) {
+impl Show for ServerTerminate with fn output(_self, logger) {
   logger <+ "ServerTerminate"
 }
diff --git a/moon.mod b/moon.mod
@@ -0,0 +1,20 @@
+name = "moonbitlang/async"
+
+version = "0.19.1"
+
+readme = "README.md"
+
+repository = "https://github.com/moonbitlang/async"
+
+license = "Apache-2.0"
+
+keywords = [ ]
+
+description = "Asynchronous programming library for MoonBit"
+
+preferred_target = "native"
+
+options(
+  source: "src",
+  exclude: [ "test_directory", "test_keys" ],
+)
diff --git a/moon.mod.json b/moon.mod.json
diff --git a/src/aqueue/deprecated.mbt b/src/aqueue/deprecated.mbt
@@ -17,6 +17,6 @@
 pub impl Show for QueueAlreadyClosed
 
 ///|
-pub impl Show for QueueAlreadyClosed with output(_self, logger) {
+pub impl Show for QueueAlreadyClosed with fn output(_self, logger) {
   logger <+ "QueueAlreadyClosed"
 }
diff --git a/src/deprecated.mbt b/src/deprecated.mbt
@@ -17,7 +17,7 @@
 pub impl Show for TimeoutError
 
 ///|
-pub impl Show for TimeoutError with output(_self, logger) {
+pub impl Show for TimeoutError with fn output(_self, logger) {
   logger <+ "TimeoutError"
 }
 
@@ -26,6 +26,6 @@ pub impl Show for TimeoutError with output(_self, logger) {
 pub impl Show for TimerCancelled
 
 ///|
-pub impl Show for TimerCancelled with output(_self, logger) {
+pub impl Show for TimerCancelled with fn output(_self, logger) {
   logger <+ "TimerCancelled"
 }
diff --git a/src/fs/access_test.mbt b/src/fs/access_test.mbt
@@ -14,10 +14,10 @@
 
 ///|
 async test "exists" {
-  assert_true(@fs.exists("moon.mod.json"))
-  @fs.open("moon.mod.json", mode=ReadOnly).close()
-  assert_false(@fs.exists("moon.mod.json.not_exist"))
-  try @fs.open("moon.mod.json.not_exist", mode=ReadOnly) catch {
+  assert_true(@fs.exists("moon.mod"))
+  @fs.open("moon.mod", mode=ReadOnly).close()
+  assert_false(@fs.exists("moon.mod.not_exist"))
+  try @fs.open("moon.mod.not_exist", mode=ReadOnly) catch {
     @os_error.OSError(_) as err if err.is_ENOENT() => ()
     err => fail("incorrect error: \{err}")
   } noraise {
@@ -30,18 +30,18 @@ async test "exists" {
 
 ///|
 async test "can_read" {
-  assert_true(@fs.can_read("moon.mod.json"))
+  assert_true(@fs.can_read("moon.mod"))
 }
 
 ///|
 async test "can_write" {
-  assert_true(@fs.can_write("moon.mod.json"))
+  assert_true(@fs.can_write("moon.mod"))
 }
 
 ///|
 #cfg(not(platform="windows"))
 async test "can_execute" {
-  assert_false(@fs.can_execute("moon.mod.json"))
+  assert_false(@fs.can_execute("moon.mod"))
 }
 
 ///|

diff --git a/src/fs/deprecated.mbt b/src/fs/deprecated.mbt
@@ -17,7 +17,7 @@
 pub impl Show for FileKind
 
 ///|
-pub impl Show for FileKind with output(self, logger) {
+pub impl Show for FileKind with fn output(self, logger) {
   match self {
     Unknown => logger <+ "Unknown"
     Regular => logger <+ "Regular"

diff --git a/src/fs/file.mbt b/src/fs/file.mbt
@@ -189,12 +189,12 @@ pub async fn create(
 ///
 /// - EOF is reached before reading all requested data
 /// - the file is a named pipe, and not enough data is available
-pub impl @io.Reader for File with _direct_read(self, buf, offset~, max_len~) {
+pub impl @io.Reader for File with fn _direct_read(self, buf, offset~, max_len~) {
   self.io.read(buf, offset~, len=max_len, context="@fs.File::read()")
 }
 
 ///|
-pub impl @io.Reader for File with _get_internal_buffer(self) {
+pub impl @io.Reader for File with fn _get_internal_buffer(self) {
   self.read_buf
 }
 
@@ -241,7 +241,7 @@ pub async fn File::read_exactly_at(
 }
 
 ///|
-pub impl @io.Writer for File with write_once(self, buf, offset~, len~) {
+pub impl @io.Writer for File with fn write_once(self, buf, offset~, len~) {
   self.io.write(buf, offset~, len~, context="@fs.File::write()")
 }