v/CHANGELOG.md

V 0.3.5

not yet released

• Struct fields can now be skipped during JSON/ORM serialization via [json:'-'] and [sql:'-'], in addition to [skip]. This allows having custom behavior for different serialization methods.
• ORM: fixed a foreign key bug that could result in an extra insert.
• Generic functions as function parameters are now supported: fn f[T](x T, i int, f_ Fn[T]) T { .
• Enum values now can have attributes.
• json: Enum value string serialization supports [json:'alias'] to change its string values.
• Functions can now return fixed size arrays.
• The builtin websocket library is now thread safe.

V 0.3.4

30 Apr 2023

Breaking Changes

The following changes may break compilation of existing code or change behavior at runtime:

• json: enums are serialized as strings by default, [json_as_number] attribute can be used for the old behavior.

  If you are serializing enums to JSON in your application, then you will need to add the [json_as_number] attribute to keep the old behavior!

• Variable shadowing has been completely banned (previously variable names could conflict with module names).

Web

• vweb now supports live page reloading. The web app is instantly updated in the browser (no need to refresh the page) every time 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.
• vweb now supports middleware.
• vweb now supports controllers. It's now possible to have multiple app structs to better separate logic.
• vweb now supports overridable .not_found() method for custom 404 pages in vweb.
• vweb now uses database pool.
• Fixed multipart form parsing in vweb.

Backends

• A new pure WASM backend, based on binaryen, a WASM builtin module, and a pure V WASM serialization library.
• Lots of fixes and new features in the native backend, including making codegen logic platform independent.
• Now code generated by the С backend, can be compiled by a C++20 compiler.
• C backend does not generate unused interface functions now.

Compiler CLI

• v share file.v for sharing code via the playground.
• v up speed up for when it hasn't been run for a long time (vc/ bootstrapping has been optimized).
• v init no longer overwrites existing src/main.v.
• v self now uses a faster TCC backend on macOS (Intel/Apple Silicon), just like on Windows/Linux.
• A new command line flag -e for running short V programs on command line: v -e "println(2+5)" ( works just like in Perl).
• A new -ldflags option, in addition to -cflags. Works just like LDFLAGS in C.

ORM

• All ORM queries now return ![] (Result of an array). This allows handling/propagating 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.

Standard Library

• Added new termios module.
• net.ssl: types using ssl contexts can now be converted to strings via .str()/printed via println().
• v.reflection: added type symbol info metadata.
• crypto and math modules have been updated to use Result instead of Option.
• datatypes.LinkedList[map] now works correctly.
• urllib.Values.get() now returns an Option.
• strconv: v_printf() was made private, v_sprintf() was deprecated. String interpolation should be used instead.
• 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.
• os.hostname() and os.loginname() now return Result.
• strconv.atoi optimizations.
• println() now supports arrays with recursive references.
• termux: support for cross-compilation from termux to other platforms.
• readline module now works much better on macOS: key navigation, history, etc (now on par with Linux).
• os: fixed a memleak in getline().
• 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.

Option as a first class type

Final steps in making the Option type a first class type:

• If guards now work with struct fields which are Option functions. Such fields can now also be assigned to other fields/variables.
• Option receivers can no longer have methods.
• none can now be cast to all Option types, including aliases.
• Option references are now supported: ?&Type.
• Arrays of Options are now allowed.
• Allow foo := Foo{}, when Foo has an Option field, that is a struct, that has a [required] tag on its fields.

Compile-time Reflection

• Compile-time interface fields evaluation.
• Compile-time enum evaluation:

  $for item in MyEnum.fields {
      println(item.value)
      println(item.name)
  }
  

• Added $option as a compile-time reflection type representing an any Option type.
• All special compile-time reflection types are now lowercase ($int, $enum, $option, etc).

Checker Improvements/Fixes

• Enums can no longer be initialized like structs.
• Capture variables can no longer shadow anonymous function params.
• Mixing multi-return results with other types in return statements is no longer allowed.
• Assigning anonymous structs to named structs is no longer allowed.
• [required] fields are now checked for embedded structs.
• Fixed a bug with closures with fixed array variables.
• Builtin methods first/last/repeat can now be used in custom user types (previously they only worked in builtin arrays).
• Generic struct initialization no longer needs explicit types to be provided:

  struct Foo[T, U] {
  	a T
  	b U
  }
  
  foo := Foo{
  	a: 2
  	b: 'x'
  }
  
  println(foo)
  

• unsafe: dereferencing nil references is no longer allowed in the following case:

  a := unsafe { nil }
  println(*a)
  

OSes

• Added basic QNX support.

Other changes

• Lots of documentation/readme improvements.
• Lots of playground improvements: play.vlang.io, including a really cool feature: "Show generated C code".
• A new [spawn_stack: 131072] function attribute for controlling the max size of the stack of the spawned threads.
• Channel pop now works with an or block: ch := <-self.item or { return none }
• it has been renamed to index in array inits.
• "Is V still fast?" web-page has been sped up by splitting the result table into multiple years.

Development

• GitHub Copilot summaries in PRs.

V 0.3.3

30 Jan 2023

• String interpolation simplified to just '${name}', enforced by vfmt, and updated in the entire code base.
• [] is now used for generics instead of <>.
• Various ORM fixes and improvements, including string interpolation support, type checks, fn calls in where.
• Accessing a pointer map value requires an or {} block outside unsafe.
• math.vec module for generic vector math including 2D, 3D, and 4D vector operations.
• go foo() has been replaced with spawn foo() (launches an OS thread, go will be used for upcoming coroutines instead).
• vfmt now supports // vfmt off and // vfmt on for turning off the formatting locally for short snippets of code. Useful for keeping your carefully arranged matrices intact.
• fast.vlang.io fixes & improvements, new server.
• New official IntelliJ plugin: https://intellij-v.github.io.
• Lots of fixes in the type checker.
• Match branch range expressions with consts: match x { const1...const2 {} }
• Builtin stb_image.h used by gg has been updated to the latest v2.28.
• Lots of new language documentation, a nicer table of contents.
• Improved documentation for most of the vlib modules
• All of vlib has been updated to use separate Option/Result types.
• To avoid confusion, all references in the code and documentation to Optional have been replaced with Option.
• gg.Context pipeline has more effects, including the additive effect.
• Hot code reloading via [live] is now supported in imported modules, not just the main module.
• VFS support in the builtin sqlite module; sqlite.get_affected_rows_count().
• make.bat & v up improvements on Windows.
• Syntax sugar for map inits without needing explicit casts for interfaces: all.children := { "abc": rect, "def": ui.rectangle()}.
• $embed_file() fixes, including variable args support.
• none fixes: no longer allowed to be used as a separate type, dump() support, not allowed inside unsafe.
• Much cleaner eof checks in os: refactor err == IError(os.Eof{}) to err is os.Eof.
• Const functions: const y = term.yellow, then println(y('abc')).
• Lots of work on x.json2, the pure V json encoder, soon to become official.
• Improved compile time checks, like $if x is Type {; $if T in [$Array, $Struct, $Alias, $Function] {.
• New v.reflection module for runtime reflection.
• Improved os.mv(), which now works consistently even across different windows drives/mount points.
• string.trim_indent(), useful with multi line strings, that start/end with new lines and indentation.
• Reduced memory consumption in the crypto modules.
• Installation instructions for using V on NixOS.
• TeamCity test runner support via v -test-runner teamcity foo_test.v.
• Better make support for OpenBSD.
• Much improved experience for v install pcre on Windows (it now bundles its own .c files, so it compiles cleanly, even if the platform does not have another pcre package installed).
• Improved vweb stability under load.
• Improved pg compatibility with older PostgreSQL versions before 2014.
• Native backend: operator support for floats, multi return.
• V can now be compiled with tcc on latest macOS and Apple Silicon.
• CI optimizations for faster runs.
• Official V UI library is now licensed under MIT.
• Deprecated math.util and math.mathutil have been removed.
• Builtin type names can no longer be used as identifiers.
• Generic typeof[T](), sizeof[T](), isreftype[T]() functions.
• New official AdventOfCode repo with AOC solutions, also added to CI.
• New time format support: time.format_rfc3339().
• encoding.html.escape().
• Deprecated -error-limit in favour of the documented -message-limit option.
• Maps now support aliased keys.
• Operator overloading now works with reference types.
• Generic struct inits with nested generic structs and generic optional types are now allowed.
• During array creation, len: is required when using default values for the array.
• Optimized one byte []u8 arrays creation.
• Int signedness mismatch is now checked: cannot use literal signed integer as u8.
• New comptime features for fields: field.is_<field>, field.is_alias, field.is_enum.
• More detailed timings in v -show-timings.
• $for in works with alias types.
• v new <name> web for quickly scaffolding new web projects.
• All public functions in the hash and encoding.base32 modules have been documented.
• Recursive aliasing is no longer allowed (e.g. type Alias = map[string]Alias).
• sqlite, pg, mysql have been moved to db.sqlite, db.pg, db.mysql.
• New crypto.pem module.
• New map.reserve() method.

V 0.3.2

31 Oct 2022

• New simplified string interpolation: println("Hello, {name}!"). It will be the only way, old syntax (${name} and $name) will be deprecated.
• New stunning playground with an improved look and feel, a much better and more responsive editor, code sharing by link, more convenient keyboard control, reusability for potential embedding: https://play.vlang.io.
• net.ssl has been migrated from a dynamically linked OpenSSL to a statically linked Mbed TLS. This means that V binaries will no longer have an OpenSSL dependency. OpenSSL can still be enabled via -d use_openssl.
• msgpack module for decoding/encoding msgpack. (v install msgpack)
• Easier custom error creation: return MyCustomErr{} instead of return IError(MyCustomErr).
• Lots of native backend improvements, including library calls, comptime conditionals, enums, method definitions/calls, structs.
• Removed the need for the [console] attribute in Windows GUI apps.
• All floats outputs now have .0 conditionally appended to them to improve clarity.
• Improved type checker: lots of new type checks and fixed checker bugs.
• Custom integer enum types: enum Xyz as u64 {.
• Some further interpreter work.
• Improved call tracing via -trace-calls.
• Most of vlib has been updated to use the new Option/Result types.
• Lots of documentation improvements, including a better documentation of the recent Option/Result split.
• net, net.http, vweb bugs and fixes.
• V REPL: Home/End keys support. Lots of clean up.
• QuadTree and RingBuffer types in datatypes.
• Forward iterator for datatypes.LinkedList<T>, forward and backward iterators for datatypes.DoublyLinkedList<T>.
• More precise WINAPI declarations for easier integration on Windows.
• Unused last expression in if is now checked.
• AST transformer fixes and optimizations.
• cgen cleanups.
• Lots of fixes in the builtin dump() function.
• Stylistic improvements and bug fixes in vfmt.
• Casting integers to enums now requires unsafe{}.
• Improved error and warning messages.
• A new maps module, similar to existing arrays. It has generic filter, flatten, invert, to_map, to_array, from_array functions.
• Parallel compilation now uses sync.Pool.
• utf8.is_number(), utf8.is_space() functions.
• New encoding.base32 module.
• -skip-unused fixes, soon to be made the default.
• gg.TouchPoint to differentiate between different types of touch input.
• Anonymous structs visibility issues fixed.
• orm: support parenthesized expressions like select from User where (name == 'Sam' && is_customer == true) || id == 1.
• vweb.csrf module.
• str.int() conversion speedup (without -prod).
• More CI tests on FreeBSD.

V 0.3.1

31 Aug 2022

• Anonymous structs.
• Lots of bug fixes: 90% of all bugs ever submitted are closed.
• Major improvements to the fast native backend including linking support on Linux. The goal is to be able to self host V soon.
• Parallelized cc step. Speeds up -prod and clang/gcc compilation by 300-500% (depending on the number of cores). Experimental and hidden behind a -parallel-cc flag, soon to be the default.
• New keyword/type: nil. Only to be used inside unsafe. Replaces voidptr(0).
• V can now find code in the src/ directory. This allows making V repos much cleaner.
• Intel C compiler support.
• Older macOS support (<10.12).
• os.mkdir() now has an optional mode parameter.
• Full termux support via $if termux {, more predictable logging on Android.
• Go backend fixes.
• More type checks.
• DOOM is now translated/compiled and launched on CI servers. A screenshot of the running game is made via vgret and is compared to the expected result.
• VLS performance improvements, especially on Windows.
• v ls tool for installing, for updating, and for launching VLS (V Language Server).
• Support assert condition, extra_message, where the extra_message will be evaluated and shown if the assertion fails.
• Anonymous sumtypes have been removed (deprecated for now) due to complicating the language and the compiler too much.
• encoding.csv is now generic, supports bools, accepts a custom delimiter, and is compatible with io.Reader/io.Writer.
• Operator overloading now works with aliases and generics.
• datatypes module now uses operator overloading.
• All datatypes types can be converted to V arrays.
• smtp improvements including multiple recipients and base64/utf8 support.
• v doc now has syntax highlighting.
• arrays.carray_to_varray<T>() for converting C arrays to V arrays.
• strconv.v_sprintf() has been deprecated in favor of string interpolation.
• TOML module now supports [toml:...] attributes, just like the JSON module.
• os.walk() is no longer recursive (still works the same).
• Windows code has been removed from v.c distributed on non-Windows systems. (v_windows.c is used on Windows.)
• ORM functions now return Result, so the errors can be handled.
• #preinclude for low level C interop.
• net.urllib ipv6 support.
• Lots of fixes in shared types.
• io has been migrated to Result.
• Third party window control in Sokol.
• Scanner optimizations.
• string.replace_char(), math.round_sig().
• Improved multiplication performance in math.big.
• net.Http.Response.text renamed to body.
• Using C's #define is no longer allowed in normal V code, only in .c.v files.
• V interpreter improvements.
• net.websocket timeout is now configurable.

V 0.3

30 Jun 2022

• C to V translation via C2V: v translate file.c. (Demo video: Translating DOOM from C to V, building it in under a second and running it!)
• Lots of bug fixes in V, cgen, and C interop to allow running translated DOOM.v.
• Programs built with the V compiler no longer leak memory by default.
• Closures. All operating systems are supported. (Demo)
• Option and Result are now separate types: ?Foo and !Foo respectively. Old code will continue working for 1 year and will result in a warning/hint.
• Hundreds of new checks in the type checker.
• All V's backends have been split up into separate processes. As the result, building V got 26% faster.
• Maps and arrays can now return options: m[bad_key] or { ... }, if x := arr[key] { ... }.
• ustring has been replaced with []rune (works just like in Go).
• Maps can now have non-string keys.
• A new compiler pass for transforming the AST (doesn't slow the compiler too much, adds about 25ms to v self). It eliminates unreachable branches and performs other simple optimizations and transformations.
• C backend is now parallel (just the cgen part for now).
• Lots of compiler source code clean up and minor optimizations. The compiler got ~30% faster according to fast.vlang.io.
• Better compiler source code organization (absolutely necessary as it's surpassed 100k loc).
• The naming of V's integer types is now more consistent: byte has been renamed to u8. Old code will continue working for 1 year and will result in a warning/hint.
• The typo detector now highlights the suggested name so that it's more visible.
• datatypes module now has Heap, Queue, Stack, BSTree, LinkedList.
• Interfaces can now be embedded (like structs).
• vlib now has a TOML parser, fully compatible with TOML 1.0.
• Lots of work done on the V.js backend, including the graphics library, which has been ported to V.js.
• JS promises, await (V.js).
• It's now possible to do more complex array initialization by using each individual element of the array ([]int{init: it}).
• Unsigned right shift operators >>> and >>>= have been added to V. (They work exactly like in Java.)
• -nofloat option, which is useful for writing kernels and for embedded systems without an FPU (used in Vinix).
• Generic interfaces.
• TCC is now bundled with the language, this allows building V programs without an external C compiler dependency.
• Null can be used in unsafe only (for example, for C interop).
• Pointer arithmetic and comparing pointers to numbers is now also only allowed in unsafe.
• Inline sumtypes.
• New module compress.gzip.
• Lots of net/net.http/vweb fixes (also used for the upcoming Gitly launch).
• IPv6 support.
• net.http headers are now enum fields instead of strings. This allows to avoid typos and offers autocomplete.
• Struct field deprecation.
• Static GC (no longer a dynamic lib dependency).
• New various algorithms for random number generation: MT19937RNG, etc (module rand).
• Fix immutability bugs that allowed to bypass compiler immutability checks and modify const/immutable values.
• Lots of fixes in the JSON serializer.
• Heap allocated only structs marked with [heap].
• Significantly improve lots of error messages, make them more clear, suggest hints.
• Bug fixes and new features in the pure V regex module.
• Lots of new drawing functions in the graphics module (like gg.draw_polygon_filled(), gg.draw_arc_empty() etc)
• Builtin FPS display in gg.
• Latest Sokol backend in gg.
• Advanced CI tests for the graphics module. Graphical apps are run on GitHub Actions instances, their output is saved to an image, uploaded, and compared to the expected result.
• More bug fixes in generics.
• Bug fixes in aliases. They can now fully replace the types they alias.
• [minify] struct attribute for struct minification.
• for in now works with fixed arrays.
• The parser was made a bit faster by skipping vfmt code when not in vfmt mode (by using -d vfmt).
• Lots of vfmt improvements, especially with comments.
• Experimental #[index] syntax for negative indexing (like in Python, but needs special syntax instead of being used by default).
• Visibility bug fixes in modules (pub).
• Error propagation in complex expressions (e.g. foo(bar()?)).
• Optionals can now by used in consts (const x := opt() or {}).
• Lots of new documentation, including vlib modules documentation and the official V Documentation.
• vpm improvements (including a new vpm mirror).
• sync improvements including sync.thread_id(), sync.Once..
• V can now be used to generate object files (foo.o) that can be used in existing C projects.
• -usecache and -skip-unused fixes, they are close to being on by default.
• Lots of Windows issues fixed.
• Amazon Linux support.
• Fixes in shared maps and arrays.
• term.ui improvements, including multi byte/UTF-8 events.
• New crypto modules, including crypto.des, crypto.cipher, crypto.blowfish.
• Comptime fixes.
• 4 byte bool option (-d 4bytebool) for compatibility with some C software.
• strconv (pure V formatting module used in string interpolation) fixes and performance improvements.
• ORM fixes (pg, mysql, sqlite). Tables are now created automatically based on the V structs, no more need in sql files to create tables for apps.
• volatile keyword.
• "stringliteral".len optimization (replaced by the actual number by the new transform pass).
• Lots of inline assembler improvements (it's used a lot in Vinix).
• Many new functions in the math module.
• Separators in number literals: 1_000_000.
• strings.Builder optimizations and new methods.
• Autofree fixes (still not production ready, hidden behind the -autofree flag).
• Lots of Android fixes in V and in vab.
• Lots of commits to the native backend (amd64/arm64).
• V interpreter fixes. (Still at an early stage.)
• Go2V translator has been started by the community, and can already translate simple programs.
• An early version of the Go backend (v -b go -o file.go file.v).

V 0.2.4

30 Aug 2021

• Introduce isize and usize types, deprecate size_t in favor of usize.
• Add datatypes and datatypes.fsm modules.
• Add compile_error and compile_warn comptime functions.
• Bare metal support. Vinix OS kernel is now being developed in V.
• Builtin web framework vweb is now multithreaded, all CPU cores are used.
• String interpolation and struct stringers are now implemented in pure V with a much cleaner and faster implementation. Previously libc's sprintf was used.
• Improved unused variable warning. Assigning to a variable no longer marks it as used. ... lots of missing changelog for this version, sorry (will update a bit later)

V 0.2.2 - 0.2.3

22 Jan 2021

• Allow interfaces to define fields, not just methods.
• vweb now uses struct embedding: app.vweb.text('hello') => app.text('hello').
• Consts can now be declared outside of const() blocks: const x = 0.
• Overloading of >, <, !=, ==, <= and >= operators.
• New struct updating syntax: User{ ...u, name: 'new' } to replace { u | name: 'new' }.
• byte.str() has been fixed and works like all other numbers. byte.ascii_str() has been added.
• Smart cast in for loops: for mut x is string {}.
• [noinit] struct attribute to disallow direct struct initialization with Foo{}.
• Array decompose: [1, 2, 3]... is now ...[1, 2, 3]
• Treating enum as int and operations on enum except == and != are removed for strict type checking.
• Support [manualfree] fn f1(){} and [manualfree] module m1, for functions doing their own memory management.
• Allow usage of < and > operators for struct in .sort method for arrays, i.e. arr.sort(a < b).
• Auto generate assignment operators like +=, -=, *=, /= and %= if the operators are defined.
• Colorize and improve failing tests output.
• Fix go with a generic function: go test<string>(c, 'abcd').
• Add comptime x := $embed_file('v.png') println(x.len) println(ptr_str(x.data())), for embedding files into binaries.
• Advanced vdoc search on mobile layout.
• string's left()/right were removed in favor of slicing syntax: str[..pos].
• gg: native graphics mode on macOS/iOS (using Cocoa Drawing API).
• Full path to consts must be specified everywhere. This makes it easy to distinguish them from local variables.
• __offsetof for low level needs (works like offsetof in C).
• vfmt now preserves empty lines, like gofmt.
• Support for compile time environment variables via $env('ENV_VAR').
• Allow method declaration of == and < operators and auto generate !=, >, <= and >=.
• support dump(expr), i.e. tracing of both the location, name and value of an expression
• deprecate os.exec in favour of os.executable() which does NOT return an option, when the command was not found

V 0.2.1

30 Dec 2020

• Hashmap bootstrapping fixes.
• Array decomposition to varargs: fn sum(i ...int) int => a := [2,3,4] println(sum(a...))
• HTML module docs generated by vdoc now have global search.

V 0.2

22 Dec 2020

• Compile-time memory management via -autofree (not production ready yet). Video demonstration.
• Channels and locks.
• Thread safe typed arrays via keyword shared.
• Struct embedding.
• IO streams (io.Reader, io.Writer etc).
• A powerful websocket module that conforms to RFC 6455 and passes the Autobahn test suite (498 client tests and 249 server tests).
• The net module is now non blocking and is more feature complete providing similar API to Go.
• V's graphics module now uses Metal/DirectX/OpenGL instead of just OpenGL.
• V can now run in the browser via WASM and execute V code by translating it to JavaScript: https://v-wasm.now.sh
• V binaries for Linux/Windows/macOS are now built and deployed automatically via GitHub Actions.
• Smart casting for sumtypes and interfaces, including complex expressions: if x.expr is int { println(x.expr + 1) }.
• Clean and easy way to sort arrays: users.sort(a.name > b.name).
• A huge amount of vfmt fixes and improvements. It has now reached a point where it can be safely used on any V source file.
• A new CI job that runs v fmt -verify on the entire code base, a new command that makes sure the file/directory has been vfmt'ed. This ensures that all code submitted to the V project is formatted.
• A new tool v vet for analyzing the project and finding potential bugs and errors.
• A new term.ui module for building dynamic terminal UIs with an example editor written in it.
• Early iOS and Android support.
• All missing ORM features from the old backend were brought back.
• Magic it variable has been replaced with smart casts (the change is completely handled by vfmt).
• Cross-compiling to Windows and Linux brought back.
• C2V can now generate wrappers. Example: https://github.com/medvednikov/libsodium. (C2V will be released by 0.3)
• C++ compiler support: code, generated by the C backend can now by compiled by C++ compilers.
• Short generics syntax: foo(5) instead of foo<int>(5).
• Cached modules via -usecache. Faster compilation due to not needing to rebuild the entire vlib for each program. Will be enabled by default in 0.2.1.
• New improved sum types implementation.
• Lots of errors that happen often during the development cycle were turned into warnings to increase development speed. They are still errors in production builds.
• Labeled break and continue.
• Lots of documentation. The official language documentation grew 3 times in size.
• modules.vlang.io is now generated automatically on every commit.
• Builtin compile-time JSON serializer now supports time.Time.
• Fixes in type aliases, to make them behave just like the types they alias.
• array.contains(element) is now generic.
• Lots of improvements in the JS backend and its type system.
• Simpler and more constinent function arg syntax: foo(a int, b int, c string) instead of foo(a, b int, c string)
• Lots of fixes and optimizations in the hashmap.
• Lots of missing checks in the type checker were added (for example, checking the correct usage of public struct fields).
• Mutability bug fixes
• Taking the address of a map value is no longer allowed, like in Go.
• Matrix multiplication.
• A new #pkgconfig flag to provide platform independent way to get compilation flags for C libraries/packages.
• Explicit parentheses requirement in complex boolean expressions.
• println was made even smarter, and can now handle complex types.
• Precompiled text templates can now be used outside of vweb via $tmpl().
• Gitly, a big web application written in vweb has been released: https://github.com/vlang/gitly
• ['/:arg1/:arg2/action'] vweb action attribute for easily getting query parameters assigned to method arguments.
• Improved performance of text rendering, gg.text_width().
• Webview module in V UI.
• Binary enum flags.
• [export] attribute to change exported function name (for example for calling from a C library).
• unsafe fixes and improvements.
• Improvements to rand: rand.ulid(), rand.uuid(), a unified customizable PRNG API.
• Hundreds of other fixes, features, and tests (from now on the changelog will be updated right away as the feature/bug fix lands).

V 0.1.27

5 May 2020

• vfmt has been re-written from scratch using the new AST parser. It's much faster, cleaner, and can format files with compilation errors.
• strconv, sprintf, and printf in native V, without any libc calls.
• Interfaces are now a lot more stable and have all expected features.
• Lots of x64 backend improvements: function calls, if expressions, for loops, local variables.
• map() and filter() methods can now be chained.
• New []int{cap:cap, len:len} syntax for initializing array length and capacity.
• New is keyword for checking the type of sum types and interfaces.
• as can now be used to cast interfaces and sum types.
• Profiling with -profile. Prints a nice table with details about every single function call: number of calls, average time per call, total time per function
• import(xxx) syntax has been removed in favor of import xxx for simplicity and greppability.
• Lots of fixes and improvements in the type checker.
• time.StopWatch
• dl module for dynamic loading.
• Automatic str() method generation for every single type, including all arrays.
• Short struct initialization syntax for imitating named function args: foo(bar:0, baz:1).
• New operator !in.
• Performance improvements in critical parts of the builtin data structures (array, map).
• High order functions improvements (functions can now be returned etc).
• Anonymous functions that can be defined inside other functions.
• Built-in JSON module is back.
• Lots and lots of new tests added, including output tests that test error messages.
• Multiple errors are now printed, the compiler no longer stops after the first error.
• The new JS backend using the AST parser (almost complete).
• Variadic functions.
• net.websocket module (early stage).
• vlib is now memory leak free, lots of autofree improvements.
• Simplified and cleaned up cmd/v, v.builder.
• V UI was updated to work with the new backend.

V 0.1.25

1 Apr 2020

• The entire compiler has been re-written with an AST parser. The code is now a lot cleaner and more maintainable. ~15k lines of old compiler code were removed.

V 0.1.24

31 Dec 2019

• A new parser/generator built on top of an AST that simplifies code greatly and allows to implement new backends much faster.
• Sum types (type Expr = IfExpr | MatchExpr | IntegerLiteral).
• B-tree map (sped up the V compiler by ~10%).
• v fmt -w.
• The entire code base has been formatted with vfmt.
• Generic structs.
• SDL module.
• Arrays of pointers.
• os: is_link(), is_dir(), exists().
• Ranging through fixed size arrays.
• Lots of fixes in ORM and vweb.
• The first tutorial: building a simple web application with vweb
• Match expressions now must be exhaustive.
• freestanding: malloc()/free().
• ++ is now required instead of += 1 for consistency.
• Interpolated strings now allow function calls: println('val = $get_val()').
• string.replace_each([]) for an efficient replacement of multiple values.
• More utf8 helper functions.
• -prealloc option for block allocations.
• type aliases.
• Running v with an unknown command will result in an error.
• atof implementation in pure V.
• Enums can now have negative values.
• New filepath module.
• math.factorial.
• ftp module.
• New syntax for casting: val as Type.
• Fewer libc functions used (soon V will have no dependency on libc).

V 0.1.23

30 Nov 2019

• Direct x64 machine code generation. Hello world being built in 3 milliseconds.
• Bare metal support via the -freestanding flag, to build programs without linking to libc.
• Prebuilt V packages for Linux, macOS, and Windows.
• string.index() now returns ?int instead of int/-1.
• Lots of fixes in Generics.
• vweb framework for developing web applications is back.
• Vorum, the forum/blogging software written in vweb, can now be compiled and has been added to CI.
• REPL, v up have been split up into separate applications to keep the core V compiler small.
• V now enforces short enum syntax (.green instead of Color.green) when it's enough.
• V UI for macOS.
• Interfaces have been rewritten. []interface support.
• os.cp() for copying files and directories.
• Additional compile-time flags: $if clang, msvc, mingw, x32, x64, big_endian, little_endian {.
• All C functions now have to be declared, all missing C functions have been defined.
• Global variables (only with the -enable-globals flag) for low level applications like kernels and drivers.
• Nothing can be cast to bool (previously code like if bool(1) { worked).
• << and >> now work with all integer types.
• V detects Cygwin and shows an error (V supports Windows natively).
• Improved type checking of some operators (%, |, & etc).
• Windows 7 support.
• println(true) now prints true instead of 1.
• os.exec() now uses CreateProcess on Windows.
• fast.vlang.io website for monitoring the performance of V after every commit.
• On Windows Visual Studio is now used automatically if GCC is not installed.
• vfmt!
• Lots of cleaning up in the compiler code.
• Multi-level pointers in unsafe code (****int).
• MSVC backtrace.
• $if os { blocks are now skipped on a different OS.
• C string literals (c'hello').
• AlpineLinux/musl fixes + added to CI.
• Inline assembly.
• Clipboard module (Windows, macOS, X).
• foo()? syntax for error propagation.
• Docs have been migrated from HTML to doc/docs.md.
• eventbus module.
• Haiku OS support.
• malloc/free on bare metal.
• utf8 helper functions (to_lower(), to_upper(), etc).
• Optimization of for c in str {.
• string/array.left/right/slice/substr were removed (use [a..b] slicing syntax instead).

V 0.1.22

28 Oct 2019

• Generic functions (fn foo<T>(bar T) T {) with varargs support.
• array[start..end] and string[start..end] slicing syntax.
• Optimized array.filter() and array.map().
• sqlite module.
• Cached modules for faster compilation.
• Dramatic compilation optimizations: V now compiles itself in 0.10 - 0.30 seconds
• V scripts (simpler and cross-platform alternative to Bash).
• Infinite multi-dimensional arrays ([][][]int).
• unsafe.
• [deprecated] attribute.
• [if] function attributes for compile time function exclusion for performance.
• switch has been completely removed from the language and replaced by match everywhere.
• pub struct and pub const, previously all structs and consts were public by default.
• musl support (V can now run on, for example, Alpine Linux).
• Module header generation. V now supports closed source modules, which are still used in some industries.
• Constants were added to typo suggestions.
• color in [.green, .red, .blue] now works without specifying Color.green.
• V compiler is now a module that can be used by other programs.
• Backtraces now have source lines on Linux.
• runtime.nr_cpus().
• fn init() for module initialization.
• a in [1, 2, 3] optimization: no array gets allocated.
• Raw strings: s := r'hello\nworld'.
• if a := func() { } syntax for handling options.
• f32/f64 comparison now uses machine epsilon by default.

V 0.1.21

30 Sep 2019

• none keyword for options.
• Solaris support.
• All table lookup functions now use none.
• varargs: fn foo(bar int, params ...string) {.
• Double quotes (") can now also be used to denote strings.
• GitHub Actions CI in addition to Travis.
• -compress option. The V binary built with -compress is only ~90 KB!
• More memory management.
• Unused modules result in an error.
• "Unused variable/module" errors are now warnings in non-production builds.
• Duplicate methods with the same name can no longer be defined.
• Struct names must be capitalized, variable/function names must use snake_case.
• Error messages are now even nicer!
• Lots of fixes in automatic .str() method generation for structs and arrays.
• ~30% faster parser (files are no longer parsed separately for each pass).
• _ is no longer a variable, but an actual syntax construct to skip unused values, like in Go.
• Multiple returns (fn foo() (int, string) {).
• ! can now only be used with booleans.

V 0.1.20

17 Sep 2019

• JavaScript backend!
• Hundreds of C warnings were fixed. gcc v.c now builds without any warnings.
• The mutability check now applies to function args (mutable receivers that are not modified result in a compilation error).
• V tests now show how long each test took.
• Official Android support (only console applications via Termux for now).
• Typo check. If a variable/function/module etc is misspelled, V will suggest the correct name.
• Lots of Microsoft C fixes, and a separate Travis instance for this backend.
• Bitwise operators |, ^, & no longer work with booleans.

V 0.1.19

12 Sep 2019

• Lots of refactoring, simplifications, and optimizations in the compiler.
• Experimental memory management at compilation (only for the V compiler itself for now).
• Lots of ORM fixes.
• Functions can now be inlined via the [inline] attribute.
• New mysql module.
• Better error format that is supported by all major editors (go to error).
• Error messages now point to the actual place where the error happened.
• Custom json field names: struct User { last_name string [json:lastName] }.
• Raw json fields via the [raw] attribute.
• All C code was removed from the freetype module.
• gg module can now render all Unicode characters.
• [typedef] attribute for imported C struct typedefs.
• Support of Objective C interfaces (primarily for using Cocoa).
• REPL: clear command and custom functions.
• REPL tests (which are also used for testing certain compiler errors).
• Syntax bug fixed: foo[0] += 10 is now possible.
• http: support plain HTTP protocol and follow redirects.
• http: header data is now processed correctly.
• net: basic UDP support.
• import const was removed from the language.
• array.contains() was removed from the language (in should be used instead).
• [0; len] syntax was removed (replaced with a simpler [0].repeat(len))
• Primitive aliases were removed to simplify the language.
• GitHub supports V now!
• Backtraces are now printed on panics.
• A new awesome readline module.
• V.c is now regenerated automatically after every commit.
• A bug with struct ordering was fixed, now structs can be declared in any order.
• V modules can now be built with v build module.
• @FILE, @LINE, @FN, @COLUMN for debugging.

V 0.1.18

16 Aug 2019

• Built-in ORM (uk_customers = db.select from Customer where country == 'uk' && nr_orders > 0).
• Map initialization syntax: m := { ‘foo’: ‘bar’, ‘baz’: ‘foo’ }.
• map.delete(key).
• libcurl dependency was removed from the http module.
• All function arguments are now immutable by default (previously they could be modified inside the function).
• http functions now return options.
• sync.WaitGroup.
• vweb static files serving.
• crypto.rand module.
• v up to update V.
• SChannel support on Windows.
• net.urllib module.
• vpm package manager, v install.
• () are now required in complex bool expressions: (a && b) || c instead of a && b || c.
• All arrays now have a default .str() method.
• Bootstrapping V with MSVC.
• Experimental ≠ etc support.
• encoding.csv module.
• $if debug { for running code in debug mode only.
• Map struct fields are now initialized automatically, just like arrays.
• Maps now support array values.
• json functions can no longer be used if the json module is not imported.

V 0.1.17

29 Jul 2019

• vweb module for developing web apps in V.
• vtalk, open source V forum software.
• Generics (very limited right now, but they will be gradually improved).
• Comptime codegen (foo.$method() where method is a string).
• @ for escaping keywords (e.g. struct Foo { @type string }).
• Windows Unicode fixes (V can now work with non-ASCII paths etc on Windows).
• Fix mutable args bugs + don't allow primitive arguments to be modified.
• Declaring a mutable variable and never modifying it results in a compilation error.
• Interactive debugging support.
• sync module for Windows.
• #! support on Unix systems (V scripts).
• Lots of Visual Studio fixes.
• crypto.aes and crypto.rc4 modules.
• Internal modules.

V 0.1.16

23 Jul 2019

• V can now be used with Visual Studio!
• Hot code reloading now works with graphical applications (e.g. graph.v, bounce.v).
• Compile time memory management for arrays.
• High order functions.
• match expression (replacing switch).
• Import cycle detection.
• crypto/md5, crypto/sha256, and crypro/sha512 modules.
• os.executable() - a cross platform function that returns full path to current executable.
• ~/.vlang and VROOT were removed entirely. The installation is a lot cleaner now.
• V can now be packaged for all Linux distros.
• Arch Linux package.
• string(bytes_buffer, len), string(bytes_array) casts.
• Multiple defers.
• key in map syntax (replacing map.exists(key)).

V 0.1.15

15 Jul 2019

• FreeBSD, OpenBSD, NetBSD, DragonFly support.
• Hot reloading now works with graphical applications: bounce.v
• VROOT was removed, the installation process is now much simpler.
• defer statement.
• map.v was re-written. It's now much faster.
• for key, val in map syntax.
• flag module for parsing command line arguments.
• zip module.
• crypto/sha1 module.
• Submodules and module aliases (import encoding.base64 as b64).

V 0.1.14

12 Jul 2019

• gg module Windows support, V Tetris runs on Windows.
• Compile glad and cJSON only once. Programs using gg or json compile a bit faster.
• v.c has been cleaned up and minimized (~16k => ~10k lines of code).
• type aliases can now have methods.
• Const overflow check during compilation (byte(1000) will no longer compile).

V 0.1.13

10 Jul 2019

• New enum syntax (token == .name), enum values are no longer global consts.
• Submodules (import encoding.base64).
• Hot code reloading.
• Special err variable for getting error values.
• Complex numbers.
• << can now append arrays (numbers << [1, 2, 3]).
• Lots of Windows fixes (Windows still needs some work).
• Lots of REPL improvements (e.g. >> 2 + 3 works now, no println required).
• The website was made easily translatable, it's now partially available in several languages.

V 0.1.12

4 Jul 2019

• V can finally compile itself on Windows (https://github.com/vlang/v#mingw-w64).
• os module now uses options in all functions that return File.
• Lots of bugs with options were fixed.
• println was optimized. It no longer results in allocations. Now it also works correctly with all integer types.
• Lots of vfmt fixes, it will be enabled tomorrow.
• New strings module.
• Lots of other fixes and improvements, thanks to all the contributors.

V 0.1.11

1 Jul 2019

• Cross compilation for Windows!
• Lots of Windows fixes.
• socket.v.
• maps fixed.

V 0.1.9 - 0.1.10

29 Jun 2019

• Windows support via MinGW-w64. Pre-built Windows binary.
• File structure has been simplified: all vlib modules were moved to the vlib/ directory, makefile was moved to the root.
• One single archive with pre-built binaries for all operating systems.
• mut var := val was fixed (previously mut var = val was allowed as well).

V 0.1.8

28 Jun 2019

• Single file programs without fn main now work as expected.
• REPL has been fixed: it now supports imports, consts, function definitions, etc.

V 0.1.7

27 Jun 2019

• All C code in the compiler and vlib has been replaced with V.
• # syntax for embedding C code has been removed.
• Exported functions now need to be marked with pub, all public vlib functions have been updated.
• CI has been set up (Travis + Azure). On every commit and PR it is made sure that V can compile itself, all tests pass, and all examples compile.
• More tests have been uploaded.
• Cleaner bytes to string conversion: tos2(bytes) => string(bytes).
• The home page has 3 more examples next to 'hello world' that show the features of the language.
• Lots of bugs and issues fixed.