V 0.3.4

30 Apr 2023

• vweb now supports live page reloading. The web app is instantly updated in the browser (no need to refresh the page) everytime a .v or a .html file is changed.
• vweb is now significantly faster and more stable under load, due to a new multithreaded worker pool, which is much more efficient at spreading the workload among all threads equally.
• Middleware support in vweb.
• vweb now supports controllers. It's now possible to have multiple app structs to better separate logic.
• vweb: overridable .not_found() method for custom 404 pages.
• A new pure WASM backend, based on binaryen, a WASM builtin module, and a pure V WASM serialization library.
• Lots of playground improvements: play.vlang.io, including a really cool feature: "Show generated C code".
• v share file.v for sharing code via the playground.
• All ORM queries now return ![] (Result of an array). This allows to handle/propagate DB errors and simplifies working with ORM (one way).
• Many ORM improvements: type checks for limit/offset/order by/where; support of reference objects in insert; struct fields can be used with limit/offset; Connection interface.
• ORM now supports the like operator: users := sql db { select from User where name like 'Bob%' }.
• A new -d trace_orm option to see all SQL queries generated and used by V ORM and -d trace_pg_error to trace PG errors.
• A new command line flag -e for running short V programs on command line: v -e "println(2+5)" (works just like in Perl).
• v up sped up for when it hasn't been run for a long time (vc/ bootstrapping has been optimized).
• Lots of new checks in the checker.
• Variable shadowing has been completely banned (previously variable names could conflict with module names).
• If guards now work with struct fields which are Option functions. Such fields can now also be assigned to other fields/variables.
• net.ssl: types using ssl contexts can now be converted to strings via .str()/printed via println().
• v.reflection: type symbol info metadata has been added.
• cgen: do not generate unused interface functions.
• A new [spawn_stack: 131072] fn attribute for controlling the max size of the stack of the spawned threads.
• Final steps in making the Option type a first class type.
• Lots of documentation/readme improvements.
• Option receivers can no longer have methods.
• none can now be cast to all Option types, including aliases.
• Enums can no longer be initialized like structs.
• Builtin methods first/last/repeat can now be used in custom user types (previously they only worked in builtin arrays).
• v init no longer overwrites existing src/main.v.
• Anonymous fn params can no longer be shadowed.
• Channel pop now works with an or block: ch := <-self.item or { return none }
• Option references are now supported: ?&Type.
• C++20 standard support in the C++ backend.
• v self now uses a faster tcc backend on macOS/Apple Silicon, just like on Windows/Linux.
• os.hostname() and os.loginname() now return Result.
• The "Is V still fast?" web page has been sped up by splitting the results table into multiple years.
• Allow foo := Foo{}, when Foo has an Option field, that is a struct, that has a [required] tag on its fields (#17516).
• Comptime reflection now supports interface fields.
• comptime: $option (for f in Foo.fields { $if f.typ is $option { ...).
• comptime: compile-time enum evaluation with `$for
• comptime: all types are now lowercase ($int, $enum, $option etc).
  item in MyEnum.fields { dump(item.value) dump(item.name) }`.
• Arrays of Options are now allowed.
• it has been renamed to index in array inits.
• datatypes.LinkedList[map] now works correctly.
• crypto and math modules have been updated to use Result instead of Option.
• [required] fields are now checked for embedded structs.
• readline module now works much better on macOS: key navigation, history, etc (now on par with Linux).
• Basic QNX support.
• A new -ldflags option, in addition to -cflags. Works just like LDFLAGS in C.
• urllib.Values.get() now returns an Option.
• strconv: v_printf() was made private, v_sprintf() was deprecated. String interpolation should be used instead.
• Fixed a bug with closures with fixed array variables.
• Generic struct inits no longer need explicit types provided: struct Foo[T, U] { a T; b U } foo := Foo{a:2, b:'x'}
• os.Process now has a create_no_window option (Windows only).
• os.Process now has a set_work_folder() method to set the initial working folder of the new child process.
• json: enums are serialized as strings by default, [json_as_number] attribute can be used for the old behavior.
• net.http: mime types have been updated to include all official types.
• gg: create_image() now returns !Image instead of Image, allowing to handle errors.
• sokol: errors during image creation no longer result in a panic, but can be handled by the programmer.
• sokol: macOS apps can now be quit using Cmd+Q.
• A new termios module.
• Lots of fixes and new features in the native backend, including making codegen logic platform-independent.
• strconv.atoi optimizations.
• println() now supports arrays with recursive references.
• Multipart form parsing fixes in vweb.
• A database pool in vweb.
• termux: support for cross-compilation from termux to other platforms.
• GitHub Copilot summaries in PRs.
• unsafe: dereferencing nil references is no longer allowed.
• os: fixed a memleak in getline().
• Mixing multi-return results with other types in return statements is no longer allowed (this simplifies the code).
• Assigning anonymous structs to named structs is no longer allowed.