Downloading Haxe 4.0.0

Release Notes

Dear Community,

On behalf of the Haxe Foundation, we are proud to announce the official release of the Haxe 4.0.0!

We have worked for almost two years on this version. We shipped 5 preview and 5 release candidate versions, each with new and improved features and bugfixes and we have now reached a point where we can present a stable release!

What's new in Haxe 4.0.0

Haxe 4.0.0 includes some of our most highly-requested features:

• New function type syntax
• Arrow function syntax
• final keyword
• New and faster Haxe built-in interpreter
• Unicode support on all targets
• Key-value iterators
• Auto-"using" for types
• IDE services protocol for better IDE support
• New high-performance run-time HashLink, a successor of Neko
• .. and much more!

To migrate from Haxe 3, read the overview of breaking changes.

See the changelog below for further details. If you have any suggestions or run into any problems, don’t hesitate to open an issue on GitHub.

We want to thank everyone involved and hope to see your codebases transition to Haxe 4 soon!

Change Log

2019-10-26: 4.0.0

New features:

• all : added -D warn-var-shadowing
• all : added column to StackItem.FilePos (#6665)
• all : added experimental null-safety feature through --macro nullSafety("package") (#7717)
• all : added final keyword (#6596)
• all : added haxe.Log.formatOutput (#6738)
• all : added JSON-RPC-based display protocol
• all : added JVM target
• all : added keyValueIterator to Map and its implementations
• all : added new function type syntax ((a:Int, b:String)->Void) (#6645)
• all : added strictness settings for the null-safety checker, using loose checking by default (#7811)
• all : added support for arrow functions
• all : added support for write-mode @:op(a.b)
• all : allow enum abstract syntax instead of @:enum abstract (#4282)
• all : allow extern on fields instead of @:extern
• all : allow enum values without arguments as default function argument values (#7439)
• all : reworked macro interpreter
• all : support @:using on type declarations (#7462)
• all : support for (key => value in e) syntax for key-value iterators
• all : support inline call() and inline new expressions (#7425)
• all : support Type1 & Type2 intersection syntax for type parameter constraints and structures (#7127)
• all : support auto-numbering and auto-stringification in enum abstracts (#7139)
• all : support loop-unrolling on for (i in 0...5) (#7365)
• all : support markup literal strings but require them to be macro-processed (#7438)
• all : support signature completion on incomplete structures (#5767)
• all : support Unicode strings properly on all targets
• hl : added hl.Format.digest, use it for native Sha1/Md5
• js : added ES6 class generation with -D js-es=6 (#7806)
• js : added js.Map and js.Set and js.JsIterator extern definitions (ES6)
• js : added js.Syntax class for generating unsupported JavaScript syntax in a type-safe analyzer-friendly way
• lua : add -D lua-vanilla, which emits code with reduced functionality but no additional lib dependencies

General improvements and optimizations:

• all : [breaking] disallow static extensions on implicit this (#6036)
• all : [breaking] disallow static extensions through abstract field casts (#5924)
• all : [breaking] disallowed static variables that have no type-hint and expression (#6440)
• all : [breaking] reserved operator and overload as keywords (#7413)
• all : added --server-connect (#8730)
• all : added @:bypassAccessor
• all : added haxe4 define
• all : added display/typeDefinition to display protocol (#7266)
• all : added support for case var x syntax and detect possible typos (#6608)
• all : allow @:commutative on non-static abstract functions (#5599)
• all : allow var ?x and final ?x parsing in structures (#6947)
• all : allow parsing #if (a.b) (#8005)
• all : allow true and false expressions as type parameters (#6958)
• all : allowed assigning [] where Map is expected (#7426)
• all : allowed enum constructors without arguments as static inline var (#8187)
• all : allowed function types in @:generic (#3697)
• all : changed haxe.xml.Fast to an abstract
• all : create temp vars in pattern matcher to avoid duplicate access (#8064)
• all : detect invalid #tokens in inactive code (#7108)
• all : do not require semicolon for markup literals (#7438)
• all : fixed various display-related problems
• all : implemented for loop unrolling (#3784)
• all : improved --help-defines and --help-metas
• all : improved --times performance (#8733)
• all : improved and unified identifier checks for names, fields and types (#8708)
• all : improved completion support in .platform.hx files
• all : improved diagnostics of syntax errors (#7940)
• all : improved display support in many areas
• all : improved handling of default values when inlining (#8397)
• all : improved handling of native libraries on the compilation server (#8629)
• all : improved memory handling of the compilation server (8727)
• all : improved optimization when comparing against null
• all : improved overall file finding (#8202)
• all : improved overall robustness of the parser in display mode
• all : improved parser error messages (#7912)
• all : improved positions of switch and case expressions (#7947)
• all : improved server reaction to added and removed files (#8451)
• all : improved support of hovering over inactive conditional compilation blocks
• all : improved unification error messages (#7547)
• all : improved various aspects of the display API
• all : inherit @:native for overriden methods (#7844)
• all : made @:expose imply @:keep (#7695)
• all : made @:using actually work
• all : made final on structure fields invariant (#7039)
• all : made all non-warning/non-error compiler messages output to stdout (#4480)
• all : made parser in display mode much more tolerant
• all : made various improvements to the display API as usual
• all : make final in structures use class notation
• all : make DCE keep constructor if any instance field is kept (#6690)
• all : make display/references and display/toplevel actually work sometimes
• all : metadata can now use ., e.g. @:a.b. This is represented as a string (#3959)
• all : properly disallowed some modifier combinations related to final (#8335)
• all : properly error on @:op(a = b) (#6903)
• all : remove some redundant cast expressions (#8725)
• all : replaced some occurrences of List with Array
• all : reworked CLI usage/help output (#6862)
• all : show typo suggestions when declaring override field (#7847)
• all : standardized identifiers allowed in markup literals (#7558)
• all : support @:pure(false) on variable fields (#8338)
• all : support override | completion
• all : support hovering conditional compilation identifiers
• all : support parsing dots in conditional compilation, e.g. #if target.sys
• all : support partial completion results (#8642)
• all : unified cast, catch and Std.is behavior of null-values (#7532)
• all : unified various parts of the String API across all targets
• cs : generate native type parameter constraints (#8311, #7863)
• cs : improved generation of enum classes (#6119)
• cs : support .NET core target (#8391)
• display : added this and super to toplevel completion (#6051)
• eval : fixed many error positions
• eval : greatly improved debugger interaction (#7839)
• eval : improved debugger, support conditional breakpoints
• eval : improved handling of capture variables (#8017)
• eval : improved IntMap and StringMap performance
• eval : improved object prototype field handling (#7393)
• eval : improved performance of instance calls
• eval : improved performance of various string operations (#7982)
• eval : optimized int switches (#7481)
• eval : properly support threads when debugging (#7991)
• eval: improved performance of regular expressions (#8693)
• flash : rework support for native Flash properties (#8241)
• flash : updated Flash externs to version 32.0 (now using final, enum abstract and haxe.extern.Rest)
• js : added externs for js.Date (#6855)
• js : enums are now generated as objects instead of arrays (#6350)
• js : generate value instanceof MyClass instead of Std.is(value, MyClass) (#6687)
• js : generate dot-access for "keyword" field names (#7645)
• js : generate faster code for x.iterator() calls (#6669)
• js : improve js.Promise extern: now then callback argument types can be properly inferred (#7644)
• js : improved generation of break inside switch inside loops (#4964)
• js : improved HTML externs
• js : optimized run-time type checking against interfaces (#7834)
• js : respect -D source-map flag to generate source maps in release builds
• js : rework exception handling, added js.Lib.getOriginalException (#6713)
• js : skip generation of interfaces when no run-time type checking needed (#7843)
• js : updated externs for Float32Array and Float64Array (#8864)
• js : updated HTML externs
• js : updated jQuery extern (js.jquery.*) for jQuery 1.12.4 / 3.2.1 support.
• js : use lazy getter for HaxeError.message instead of calling String(val) in the ctor (#6754)
• lua : improved -D lua-vanilla
• macro : static variables are now always re-initialized when using the compilation server (#5746)
• macro : support @:persistent to keep macro static values across compilations
• Makefile : default Unix installation location $(INSTALL_DIR) changed from /usr to /usr/local.
• Makefile : default Unix std location $(INSTALL_STD_DIR) changed from $(INSTALL_LIB_DIR)/std to $(INSTALL_DIR)/share/haxe/std.
• php : added php.Syntax.code() instead of deprecated untyped __php__() (#6708)
• php : added array access to php.NativeStructArray (#8893)
• php : added methods to php.Syntax for each php operator: ??, ?:, ** etc. (#6708)
• php : changed --php-prefix, --php-front and --php-lib to -D php-prefix=, -D php-front= and -D php-lib= respectively
• php : implemented direct method comparison. No need to use Reflect.compareMethods()
• php : improved performance of various parser implementations (#8083)
• php : Optimized Map.copy() and Array.copy()
• php : Optimized haxe.ds.Vector (VectorData is not Array anymore)
• php : Optimized iterators of Map and native arrays.
• php : Support native PHP generators. See php.Syntax.yield() and php.Generator
• python : add ssl support for http requests
• python : improve Sys.print(ln) code generation (#6184)
• sys : the database parameter of Mysql.connect is now optional

Standard Library:

• all : [breaking] made Lambda functions return Array instead of List (#7097)
• all : [breaking] removed return this from some haxe.Http methods (#6980)
• all : BalancedTree implements haxe.Constraints.IMap` (#6231)
• all : added EReg.escape (#5098)
• all : added iterator() to haxe.DynamicAccess (#7892)
• all : added keyValueIterator() to haxe.DynamicAccess (#7769)
• all : added resize to Array (#6869)
• all : added default timeout to HTTP sockets (#8646)
• all : added haxe.iterators package
• all : added JSON-RPC protocol types to haxe.display package (#8610)
• all : added Map.clear (#8681)
• all : added StringTools.contains (#7608)
• all : improved Date API (#8508)
• all : improved StringTools.lpad/rpad/htmlEscape implementation
• all : introduced Std.downcast as replacement for Std.instance (#8301)
• all : introduced UnicodeString, deprecated haxe.Utf8 (#8298)
• all : moved List to haxe.ds (#6610)
• all : moved typed arrays from js.html to js.lib (#7894)
• all : turned sys.thread.Thread into abstracts (#8130)
• all : unified various Thread APIs in sys.thread (#7999)
• cs : added sys.thread implementations (#8166)
• eval : completed Thread API
• flash : added flash.AnyType (#8549)
• java : added java.NativeString (#8163)
• js : moved various classes to js.lib (#7390)
• macro : added Context.getMessages and Context.filterMessages (#8471)
• macro : added Context.info (#8478)
• macro : added function kind to EFunction (#8653)
• macro : added have.display.Position and PositionTools.toRange (#6599)
• macro : added string literal kind to CString (#8668)

Bugfixes:

• all : [breaking] function () { }(e) is no longer parsed as a call (#5854)
• all : cleaned up inline handling (#7155)
• all : delay interface accessor generation properly (#6225, #6672)
• all : disallowed return null from Void-functions (#7198)
• all : don't generate return expressions in Void lambda functions (#6503)
• all : fix GC compacting too often in server mode
• all : fix some invalid Json being accepted by haxe.format.JsonParser (#6734)
• all : fixed @:generic naming (#6968)
• all : fixed @:structInit not being compatible with final fields (#7182)
• all : fixed -D no-deprecation-warnings for typedefs and enums
• all : fixed @:allow(package) allowing too much (#8306)
• all : fixed from Dynamic on abstracts (#8425)
• all : fixed inline new handling (#8240)
• all : fixed Null<T> inconsistency in if/ternary expressions (#6955)
• all : fixed abstract @:to used when from is available in a specific case (#6751)
• all : fixed and restricted various Unicode-related issues in String literals
• all : fixed argument default value checking for externs (#7752)
• all : fixed autogenerated constructor for extending @:structInit classes (#6822, #6078)
• all : fixed bad unary operator optimization (#7704)
• all : fixed bug regarding abstract this modification in inline methods (#8454)
• all : fixed bug that skipped checking @:from typing in some cases (#6564)
• all : fixed call-site inlining on abstracts (#7886)
• all : fixed capture variables being allowed in .match (#7921)
• all : fixed cast handling in try-catch expressions (#8257)
• all : fixed compilation server module dependency issue related to macros (#7448)
• all : fixed compiler hang in display mode (#7236)
• all : fixed compiler hang related to @:arrayAccess (#5525)
• all : fixed Constructible not checking constraints properly (#6714)
• all : fixed DCE compilation server state issue (#7805)
• all : fixed DCE issue related to closures (#8200)
• all : fixed field type being lost for Int expressions on Float fields (#7132)
• all : fixed fields with default values for @:structInit classes (#5449)
• all : fixed handling of type parameters in local functions (#6560)
• all : fixed haxe.format.JsonPrinter for instances of classes to make it produce consistent result across targets (#6801)
• all : fixed infinite recursion on @:generic field access (#6430)
• all : fixed infinite recursion related to printing of objects with circular references (#8113)
• all : fixed Int64 parsing of negative numbers that end in a zero (#5493)
• all : fixed invalid static extension lookup on super (#3607)
• all : fixed invalid visibility unification with statics (#7527)
• all : fixed issue with @:generic type parameters not being bound to Dynamic (#8102)
• all : fixed issue with various functions not being displayed in macro context (#6000)
• all : fixed local variable type information being lost on the compilation server (#8511)
• all : fixed macro @:from methods allowing any return type (#8463)
• all : fixed optional status of overloaded arguments with default values (#7794)
• all : fixed overeager recursive inline check (#8489)
• all : fixed pattern matcher allowing invalid abstract unification (#8579)
• all : fixed pattern matcher issue with wildcards in or-patterns (#8296)
• all : fixed resolution order between untyped and type parameters (#7113)
• all : fixed the pattern matcher allowing inexhaustive switches in value-places (#8277)
• all : fixed the XML printer trimming CDATA content (#7454)
• all : fixed top-down inference on abstract setters (#7674)
• all : fixed top-down inference when constructing enums (#6606)
• all : fixed typing error when constructing enums with abstracts over functions (#6609)
• all : fixed unbound variable error in anonymous functions (#6674)
• all : fixed unification behavior in try/catch expressions (#7120)
• all : fixed unification of recursive typedefs again (#8523)
• all : fixed various GADT-related problems (#7672)
• all : fixed various hangs related to abstracts (#8588)
• all : fixed various issues related to @:structInit
• all : fixed various issues with diagnostics
• all : fixed various issues with startIndex handling on String.indexOf and String.lastIndexOf
• all : fixed various minor inlining issues
• all : fixed various pattern matching problems
• all : fixed various pattern matching problems
• all : fixed various position and replace ranges in the display API
• all : fixed various priority issues regarding loops and iterators
• all : fixed various problems related to DCE and feature-handling (#7694)
• all : fixed various wrong positions when encoding data to macros
• all : fixed visibility check related to private constructors of sibling classes (#6957)
• all : specified String.indexOf with out-of-bounds indices (#7601)
• all : sys.Http: fix chunked encoding handling (#6763)
• all: fixed regression of macro @:from methods on abstracts (#8779)
• all: fixed regression, which caused compiler to crash on enum abstracts with explicit casting (#8765)
• all: fixed switching on this (#8781)
• cpp : fixed Socket flags not being preserved (#7989)
• cpp : fixed some leftover unicode issues
• cpp : fixed various issues related to casts
• cs : fix order-dependent enum type parameter issue (#6016)
• cs : fixed "This expression may be invalid" false warning (#8589)
• cs : fixed bad evaluation order in structures (#7531)
• cs : fixed NativeArray casting (#3949)
• cs/java : fixed DCE bug that would lose toString method of thrown objects
• cs/python : fixed various issues with code generation
• display : fixed completion in packages starting with underscore (#5417)
• eval : don't lose dynamic function inits from parent classes (#6660)
• eval : fixed bad string conversions on invalid + operations
• eval : fixed bug with equality handling
• eval : fixed infinite recursion when printing arrays/vectors
• eval : fixed int switch bug related to overflows
• eval : fixed internal exception surfacing in some context calls (#7007)
• eval : fixed invalid override detection (#6583)
• eval : fixed issue with file creation not defaulting to binary
• eval : fixed Socket.setTimeout (#7682)
• eval : fixed Type.enumEq (#6710)
• eval : fixed various problems with the debugger
• eval : fixed Vector.fromArrayCopy (#7492)
• flash : fix various issues, including native protected handling and method overloading
• flash : fixed silently swallowing exceptions in getters/setters when invoked with Reflect methods (#5460, #6871)
• flash : fixed var field access on interfaces being uncast (#7727)
• hl : fixed sqlite connection on OSX/Linux (#8878)
• hl : fixed various String Unicode issues
• java : fixed backslash escaping on EReg.replace (#3430)
• java : fixed null exception in CallStack.exceptionStack (#8322)
• java : fixed Std.is on non-reference and unrelated types (#5168)
• java/jvm : fix switch on null string (#4481)
• java/macro : fixed null-pointer exception in Reflect.getProperty (#4934)
• js : fixed bad stack handling on Map constraint checks (#7781)
• js : fixed code generation issue related to negative abstract values (#8318)
• js : fixed DCE issues related to haxe.CallStack (#7908)
• js : fixed js syntax error for value.iterator-- (#6637)
• js : fixed saving setter to tmp var before invocation (#6672)
• js : fixed syntax problem related to instanceof (#7653)
• js : fixed typed array APIs (#8422)
• jvm : fixed boxed vs. unboxed comparison (#8577)
• jvm : generate toplevel types to haxe.root like genjava does (#8590)
• jvm : improved 32bit support (#8601)
• lua : fix toString behavior in the case of -0 (#6652)
• lua : fixed @:expose for classes inside packages (#7849)
• lua : fixed EReg.map for unicode (#8861)
• lua : fixed StringTools.fastCodeAt with -D lua-vanilla (#7589)
• lua : fixed broken output when compiling through the compilation server (#7851)
• lua : fixed issue where Process output occasionally is missing some data
• lua : properly bind field functions when passed as arguments (#6722)
• macro : fixed Array.pop handling (#8075)
• macro : fixed assertion failure when throwing exception (#8039)
• macro : fixed Sys.programPath assertion failure (#8466)
• macro : fixed various uncatchable exceptions being thrown
• php : don't fail on generating import aliases for classes with the similar names (#6680)
• php : error on case-insensitive name clashes (#8219)
• php : Escape $ in field names of anonymous objects (#7230)
• php : fixed -2147483648 as init value for static vars (#5289)
• php : fixed Sys.environment() to also return variables set by Sys.putEnv()
• php : fixed sys.net.Socket.bind() (#6693)
• php : fixed accessing static inline var via reflection (#6630)
• php : fixed an issue with "Object" used as a class name for PHP 7.2 (it's a new keyword in php) (#6838)
• php : fixed appending "sqlite:" prefix to the names of files created by sys.db.Sqlite.open() (#6692)
• php : fixed class naming conflicts (#7716)
• php : fixed iterator fields on maps being removed (#8851)
• php : fixed Math.min() and Math.max() for NAN on PHP 7.1.9 and 7.1.10
• php : fixed multiple file uploads in php.Web.parseMultiPart() (#4173)
• php : fixed php error on parsing expressions like a == b == c (#6720)
• php : fixed Reflect.callMethod with classes as first argument (#7106)
• php : Generate switch as if...else if...else... to avoid loose comparison (#7257)
• php : made php.Lib.objectOfAssociativeArray() recursive (#6698)
• php: fix field access on new MyClass() expressions wrapped in a cast (#6294)
• php: fix invoking functions stored in dynamic static vars (#6158)
• php/php7: fix "cannot implement previously implemented interface" (#6208)
• php/php7: fixed accessing enum constructors on enum type stored to a variable (#6159)
• php/python : fixed some bit operators for Int32 (#5938)
• php7: fix @:enum abstract generation without -dce full (#6175)
• php7: fix null property access (#6281)
• php7: fix haxe.io.Input.readAll() with disabled analyzer optimizations (#6387)
• php7: fix Reflect.field() for strings (#6276)
• php7: fix setting values in a map stored in another map (#6257)
• php7: fix using enum constructor with arguments as a call argument (#6177)
• python : fixed modulo by a negative number (#8845)
• sys : fixed various Unicode issues (#8135)

Removals:

• all : consistently disallowed metadata in lambda function arguments (#7800)
• all : disallowed \x with values > 0x7F (#8141)
• all : disallowed implements Dynamic on non-extern classes (#6191)
• all : disallowed default values on interface variables (#4087)
• all : disallowed get_x/set_x property syntax, use get/set instead (#4699)
• all : disallowed macro-in-macro calls (#7496)
• all : moved haxe.remoting to hx3compat
• all : moved haxe.unit to hx3compat
• all : moved haxe.web.Dispatch into hx3compat library (https://github.com/HaxeFoundation/hx3compat).
• all : moved haxe.web.Request to hx3compat
• all : remove support for @:fakeEnum enums
• all : removed --eval command line argument
• all : removed --gen-hx-classes (#8237)
• all : removed -D use-rtti-doc, always store documentation instead (#7493)
• all : removed support for T:(A, B) constraint syntax
• all : warn about expressions in extern non-inline fields (#5898)
• it's recommended to use more modern js.jquery.JQuery and js.swfobject.SWFObject classes.
• js : js.JQuery and js.SWFObject were moved into hx3compat library (https://github.com/HaxeFoundation/hx3compat),
• js : moved js.XMLSocket to hx3compat
• js : removed jQuery and swfobject externs (#7494)
• macro : deprecated Context.registerModuleReuseCall and onMacroContextReused (#5746)
• neko : moved neko.net to hx3compat
• php : deprecated support for untyped __php__, untyped __call__ etc. Use php.Syntax instead.
• php : dropped php5 support; minimum supported php version is 7.0 now
• php : removed php.Syntax.binop() (#6708)
• sys : SPOD (sys.db.Object, sys.db.Manager and friends) was moved into a separate library record-macros (https://github.com/HaxeFoundation/record-macros)

Getting Started With Haxe

Now that you've downloaded Haxe, you can get started with a specific platform. Click on a logo to learn how to set up the development environment and how to proceed from there:

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For getting started with Haxe, take a look at our introduction, read through the Haxe Manual or look at these use cases for Haxe, including tutorials and popular libraries:

• Games
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• Desktop Apps
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