# Announcement **URL:** https://discuss.moonbitlang.com/c/announcement/5.md [Latest](https://discuss.moonbitlang.com/latest.md) · [Categories](https://discuss.moonbitlang.com/categories.md) · [Tags](https://discuss.moonbitlang.com/tags.md) --- ## [About the Announcement category](https://discuss.moonbitlang.com/t/about-the-announcement-category/16)
**Author:** [@Hoey](https://discuss.moonbitlang.com/u/Hoey)\ **Replies:** 0
Official announcements from the Moonbit team --- ## [Vol.71 MoonBit Update](https://discuss.moonbitlang.com/t/vol-71-moonbit-update/361)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [May 6, 2025, 9:48am UTC](https://discuss.moonbitlang.com/t/vol-71-moonbit-update/361 "2025-05-06T09:48:51Z")
2025-05-06 Language Updates \[Breaking Change\] The way traits are implemented will change. In the future, traits must be explicitly implemented for a type A using impl T for A { ... }. Simply defining methods on A with … --- ## [Vol.69 MoonBit Update](https://discuss.moonbitlang.com/t/vol-69-moonbit-update/355)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [April 7, 2025, 9:45am UTC](https://discuss.moonbitlang.com/t/vol-69-moonbit-update/355 "2025-04-07T09:45:16Z")
2025-04-07 Language Updates Wasm Backend: extern type T Now Storable in Arrays and Data Structures The wasm backend now supports storing values of extern type T in arrays and other data structures. At FFI boundaries (imp… --- ## [Vol.68 MoonBit Update](https://discuss.moonbitlang.com/t/vol-68-moonbit-update/353)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [March 24, 2025, 10:06am UTC](https://discuss.moonbitlang.com/t/vol-68-moonbit-update/353 "2025-03-24T10:06:58Z")
2025-03-24 Language Updates Pattern Matching for Bytes Bytes can now use array patterns for pattern matching. fn main { let bytes : Bytes = "Hello, world!"; match bytes { \[..b"Hello", ..\] =\> { println("Sta… --- ## [Vol.67 MoonBit Update](https://discuss.moonbitlang.com/t/vol-67-moonbit-update/351)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [March 10, 2025, 10:18am UTC](https://discuss.moonbitlang.com/t/vol-67-moonbit-update/351 "2025-03-10T10:18:17Z")
2025-03-10 Language Updates Pattern Guards Pattern guards can be specified by appending if ... to a pattern. A branch with a pattern guard will only execute if the matched value satisfies the pattern and the guard condit… --- ## [Vol.66 MoonBit Update](https://discuss.moonbitlang.com/t/vol-66-moonbit-update/345)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [February 24, 2025, 10:09am UTC](https://discuss.moonbitlang.com/t/vol-66-moonbit-update/345 "2025-02-24T10:09:33Z")
2025-02-24 Language Update Enhancements to String Pattern Matching a. Support for String Literals in Array Patterns You can now use the .. operator to match a substring within an array pattern of type String: let str =… --- ## [Vol.65 MoonBit Update](https://discuss.moonbitlang.com/t/vol-65-moonbit-update/339)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [February 11, 2025, 2:44am UTC](https://discuss.moonbitlang.com/t/vol-65-moonbit-update/339 "2025-02-11T02:44:21Z")
2025-02-10 Language Updates New is Expression The syntax for this expression is expr is pat. The expression is a Bool type and evaluates to true when expr matches the pattern pat. For example: fn use\_is\_expr(x: Int?) -\>… --- ## [Vol.64 MoonBit Update 0113](https://discuss.moonbitlang.com/t/vol-64-moonbit-update-0113/333)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [January 13, 2025, 10:54am UTC](https://discuss.moonbitlang.com/t/vol-64-moonbit-update-0113/333 "2025-01-13T10:54:30Z")
2025-01-13 Language Updates Experimental Async Support Experimental support for asynchronous programming has been added. You can declare asynchronous functions using async fn ... and call them with f!!(...). MoonBit a… --- ## [Vol.63 MoonBit Update 1230](https://discuss.moonbitlang.com/t/vol-63-moonbit-update-1230/331)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [December 30, 2024, 10:27am UTC](https://discuss.moonbitlang.com/t/vol-63-moonbit-update-1230/331 "2024-12-30T10:27:14Z")
2024-12-30 Language Update Added labeled loop syntax, which allows you to jump directly to a specified layer in a multi-layer loop, using ~ as the suffix for the label. fn f\[A\](xs : ArrayView\[A\], ys : Iter\[Int\]) -\> @im… --- ## [Vol. 62 MoonBit Update](https://discuss.moonbitlang.com/t/vol-62-moonbit-update/325)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [December 16, 2024, 9:54am UTC](https://discuss.moonbitlang.com/t/vol-62-moonbit-update/325 "2024-12-16T09:54:54Z")
2024-12-06 Language Update New Trait object syntax: &Trait Trait object syntax has been changed from writing Trait directly to &Trait (the old syntax has been deprecated). We made this change to separate trait object t… --- ## [Vol.61 MoonBit Update 1202](https://discuss.moonbitlang.com/t/vol-61-moonbit-update-1202/319)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [December 2, 2024, 9:50am UTC](https://discuss.moonbitlang.com/t/vol-61-moonbit-update-1202/319 "2024-12-02T09:50:38Z")
2024-12-02 Language Updates Added support for range patterns to match a range of integer or character values in pattern matching. The syntax for range patterns is a..\ **Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [November 18, 2024, 10:29am UTC](https://discuss.moonbitlang.com/t/vol-60-moonbit-update-1118/312 "2024-11-18T10:29:29Z") 2024-11-18 Language Updates Trait now has abstract and pub(readonly) visibility. An abstract/readonly trait behaves the same as a fully public trait within the current package. Outside the current package, you can… --- ## [Vol.59 MoonBit Update 1104](https://discuss.moonbitlang.com/t/vol-59-moonbit-update-1104/311)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [November 4, 2024, 10:32am UTC](https://discuss.moonbitlang.com/t/vol-59-moonbit-update-1104/311 "2024-11-04T10:32:54Z")
2024-11-04 Language Updates Compile-time Constants Support Introduced support for constants declared with const C = ..., where names start with uppercase letters. Must be built-in numeric types or String. Constants can… --- ## [MoonBit Update——1021](https://discuss.moonbitlang.com/t/moonbit-update-1021/300)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [October 21, 2024, 10:06am UTC](https://discuss.moonbitlang.com/t/moonbit-update-1021/300 "2024-10-21T10:06:27Z")
2024-10-21 Language Update MoonBit native backend support Js-string-builtins proposal support for Wasm-gc backend When the -use-js-builtin-string compiler option is enabled, MoonBit strings will be represented with… --- ## [MoonBit Update——1014](https://discuss.moonbitlang.com/t/moonbit-update-1014/296)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [October 14, 2024, 6:13am UTC](https://discuss.moonbitlang.com/t/moonbit-update-1014/296 "2024-10-14T06:13:23Z")
MoonBit Update IDE Update AI Codelens now supports /generate and /fix commands. The /generate command provides a generic interface for generating code. https://cdn.discordapp.com/attachments/1293108131877879808/12931… --- ## [MoonBit Update——0903](https://discuss.moonbitlang.com/t/moonbit-update-0903/286)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [September 3, 2024, 9:40am UTC](https://discuss.moonbitlang.com/t/moonbit-update-0903/286 "2024-09-03T09:40:58Z")
Language Updates Breaking Change: String interpolation syntax changed from \\() to \\{} where more expression types within \\{} are supported. For example: fn add(i: Int) -\> Int { i + 1 } fn main { println("\\{add(2)}… --- ## [MoonBit Update——0819](https://discuss.moonbitlang.com/t/moonbit-update-0819/281)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [August 19, 2024, 9:37am UTC](https://discuss.moonbitlang.com/t/moonbit-update-0819/281 "2024-08-19T09:37:11Z")
Language Update MoonBit Beta Preview MoonBit Beta Preview achieved major features of modern generic system, precise error handling, and efficient iterators, and AI-powered toolchain, offering real use cases in cloud an… --- ## [The MoonBit Update——0812](https://discuss.moonbitlang.com/t/the-moonbit-update-0812/278)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [August 12, 2024, 10:24am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0812/278 "2024-08-12T10:24:04Z")
Language Update Added support for for .. in loops based on Iter and Iter2 types: fn main { for x in \[1, 2, 3\] { println(x) } for k, v in {"x": 1, "y": 2} { println("\\{k} =\> \\{v}") } } You can bind one… --- ## [The MoonBit Update——0805](https://discuss.moonbitlang.com/t/the-moonbit-update-0805/273)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [August 5, 2024, 9:20am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0805/273 "2024-08-05T09:20:06Z")
Language Update JSON Literal Support for Array Spread: let xs: Array\[@json.JsonValue\] = \[1, 2, 3, 4\] let \_: @json.JsonValue = \[1, ..xs\] Type Alias Support: Added support for type aliases, primarily for gradual code r… --- ## [The MoonBit Update——0729](https://discuss.moonbitlang.com/t/the-moonbit-update-0729/272)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [July 29, 2024, 10:43am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0729/272 "2024-07-29T10:43:17Z")
weekly 2024-07-29 Language Updates Simplified Error Handling Syntax: The syntax for capturing potential errors in function calls has been updated from f(x)!! to f?(x), which returns a Result type. fn div(x: Int, y: Int… --- ## [The MoonBit Update——0722](https://discuss.moonbitlang.com/t/the-moonbit-update-0722/271)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [July 22, 2024, 10:04am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0722/271 "2024-07-22T10:04:47Z")
Language Updates Breaking Changes Error Handling Syntax: The syntax for error handling has changed from f(x)! to f!(x). This change facilitates IDE auto-completion, allowing the function name and ! to be completed toge… --- ## [The MoonBit Update——0708](https://discuss.moonbitlang.com/t/the-moonbit-update-0708/266)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 3\ **Last updated:** [July 16, 2024, 7:38am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0708/266 "2024-07-16T07:38:39Z")
Language Update \[Breaking change\] Modified array slice syntax from arr\[start..end\] to arr\[start:end\] similar to Python. This change is made to avoid syntax conflicts with the upcoming cascade method call x..f(). The ol… --- ## [The MoonBit Update——0715](https://discuss.moonbitlang.com/t/the-moonbit-update-0715/269)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [July 15, 2024, 9:43am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0715/269 "2024-07-15T09:43:24Z")
weekly 2024-07-15 Language Update New syntax: Cascade Operator MoonBit introduces the “..” operator, allowing for chaining of mutable API calls while keeping the mutable API signatures clean (still returning Unit). As… --- ## [The MoonBit Update——0617](https://discuss.moonbitlang.com/t/the-moonbit-update-0617/251)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 5\ **Last updated:** [July 6, 2024, 4:16am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0617/251 "2024-07-06T04:16:09Z")
Language Update Supported error handling: Functions can now specify return types with error handling using the syntax Int!String. The following example means the function returns an Int under normal conditions, and th… --- ## [The MoonBit Update——0701](https://discuss.moonbitlang.com/t/the-moonbit-update-0701/264)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [July 1, 2024, 9:46am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0701/264 "2024-07-01T09:46:43Z")
Language Update Enabled simplifying the type prefix for enum constructor: When there is no ambiguity, you can omit the type prefix for enum constructors. For example, you can now write Some(42) instead of Option::Some… --- ## [The MoonBit Update——0624](https://discuss.moonbitlang.com/t/the-moonbit-update-0624/258)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 6\ **Last updated:** [June 25, 2024, 2:01am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0624/258 "2024-06-25T02:01:38Z")
Language Update Support 32-bit unsigned integers let num = 100U // Literal for 32-bit unsigned integers requires the 'U' suffix WASM Backend Export Improvements When exporting functions with a return type of Unit … --- ## [The MoonBit Update——0611](https://discuss.moonbitlang.com/t/the-moonbit-update-0611/250)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [June 11, 2024, 7:38am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0611/250 "2024-06-11T07:38:10Z")
Language Update Wasm MVP: Added reference counting support based on the Perceus algorithm to the Wasm1 backend. Syntax: throw, raise, try, and catch are reserved as keywords in preparation for the upcoming error han… --- ## [The MoonBit Update——0603](https://discuss.moonbitlang.com/t/the-moonbit-update-0603/248)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [June 3, 2024, 9:28am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0603/248 "2024-06-03T09:28:36Z")
Language Update A new syntax T? has been added for type annotations to represent Option\[T\]. struct Cell\[T\] { val: T next: Cell\[T\]? } fn f(x : Cell\[T\]?) -\> Unit { ... } This is equivalent to struct Cell\[T\] { va… --- ## [The MoonBit Update——0527](https://discuss.moonbitlang.com/t/the-moonbit-update-0527/241)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [May 27, 2024, 9:59am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0527/241 "2024-05-27T09:59:32Z")
MoonBit Update 0527 MoonBit is a Rust-like programming language (with GC support) and toolchain optimized for WebAssembly. Language Update Breaking Change: Restructure APIs of MoonBit Core library. Placing all immut… --- ## [The MoonBit Update——0520](https://discuss.moonbitlang.com/t/the-moonbit-update-0520/238)
**Author:** [@Kuki](https://discuss.moonbitlang.com/u/Kuki)\ **Replies:** 0\ **Last updated:** [May 20, 2024, 9:26am UTC](https://discuss.moonbitlang.com/t/the-moonbit-update-0520/238 "2024-05-20T09:26:43Z")
MoonBit is a Rust-like programming language (with GC support) and toolchain optimized for WebAssembly. Language Update Breaking Change: Rename Array to FixedArray, @vec.Vec to Array // Before fn init { let array : … [Next page](https://discuss.moonbitlang.com/c/announcement/5.md?page=1)