3.16.0

• require OCaml >= 4.08 (@anmonteiro, #2840)
• support ppxlib with OCaml 5.2 AST (and require ppxlib >= 0.36) (@anmonteiro, #2835)

3.15.0

• rtop: read ~/.config/rtop/init.re configuration file (@anmonteiro, #2813)

  • the -init FILE flag works as before
• rtop: ignore ~/.ocamlinit.ml or ~/.config/utop/init.ml config files (@anmonteiro, #2813)
• Add support for raw identifier syntax (@anmonteiro, #2796)
• Fix: display attributes in record field and JSX props under punning (@pedrobslisboa, #2824)
• Support modest Unicode letters in identifiers (@anmonteiro, #2828)
• refmt: fix file descriptor leak (@anmonteiro, #2830)

3.14.0

• Support OCaml 5.3 (@anmonteiro, #2800)
• Fix: don't print all extension strings as quoted extensions (@anmonteiro, #2809)
• Fix: unify printing of extensions across structure items / expressions (@anmonteiro, #2814)

3.13.0

• Support module%ppx syntax (@anmonteiro, #2771)
• Extend open to arbitrary module expression (@anmonteiro, #2773)
• Wrap let lazy patterns = .. in parentheses (let lazy(patterns) = ..) (@anmonteiro, #2774)
• Print poly variants as normal variants (@Sander Spies, #2708)
• Improve printing of anonymous function return type (@Sander Spies, #2686)
• Improve printing of destructuring with local open (@Sander Spies, #2684).
• Parse and print attributes in binding let ops (@anmonteiro, #2777).
• Parse polymorphic variants starting with [| (@anmonteiro, #2781)
• Always add a line break in records with 2 or more fields (@anmonteiro, #2779)
• Always break nonempty doc comments after */ (@anmonteiro, #2780)
• Improve printing of arrows with labelled arguments (@anmonteiro, #2778)
• Parse and print extensions in open%foo expressions and structure items (@anmonteiro, #2784)
• Add support for module type substitutions (@anmonteiro, #2785)
• Support type%foo extension sugar syntax (@anmonteiro, #2790)
• Support quoted extensions (@anmonteiro, #2794)
• Parse universal type variables in signature items (@anmonteiro, #2797)
• Fix formatting of callbacks with sequence expressions (@anmonteiro, #2799)
• Fix printing of attributes on module expressions (@anmonteiro, #2803)

3.12.0

• Add \u{hex-escape} syntax (@anmonteiro, #2738)
• Support local open and let bindings (@SanderSpies) #2716
• outcome printer: change the printing of @bs.* to @mel.* (@anmonteiro, #2755)
• Fix outcome printing of optional arguments on OCaml 5.2 (@anmonteiro, #2753)
• support parsing and printing of external%extension (@anmonteiro, #2750, #2766, #2767)
• install refmt manpage (@anmonteiro, #2760)
• add support for parsing / printing of refutation clause in switch (@anmonteiro, #2765)
• support let%ppx in signatures (@anmonteiro, #2770)

3.11.0

• Print structure items extension nodes correctly inside modules (@anmonteiro, #2723)
• Print wrapped type constraint on record patterns (@anmonteiro, #2725)
• Support OCaml 5.2 (@anmonteiro, #2734)

3.10.0

• Support @mel.* attributes in addition to @bs.* (@anmonteiro, #2721)

3.9.0

• Reduce the amount of parentheses around functor usage (@SanderSpies, #2683)
• Print module type body on separate line (@SanderSpies, #2709)
• Fix missing patterns around contraint pattern (a pattern with a type annotation).
• Fix top level extension printing
• Remove the dependency on the result package, which isn't needed for OCaml 4.03 and above (@anmonteiro) #2703
• Fix the binary parser by converting to the internal AST version used by Reason (@anmonteiro) #2713
• Port Reason to ppxlib (@anmonteiro, #2711)
• Support OCaml 5.1 (@anmonteiro, #2714)

3.8.2

• Fix magic numbers for OCaml 5.0 (@anmonteiro) #2671

3.8.1

• (Internal) Rename: Reason_migrate_parsetree -> Reason_omp (@ManasJayanth) #2666
• Add support for OCaml 5.0 (@EduardoRFS and @anmonteiro) #2667

3.8.0

• Add support for OCaml 4.13 (@EduardoRFS and @anmonteiro) #2657
• Add support for OCaml 4.14 (@EduardoRFS and @anmonteiro) #2662

3.7.0

• Add support for (limited) interop between letop + OCaml upstream (@anmonteiro) #2624
• Add support for OCaml 4.12 (@kit-ty-kate) #2635
• Remove support for OCaml 4.02.3 (@anmonteiro) #2638

3.6.2

New Feature, Non Breaking:

• Reason Syntax v4 [NEW-FEATURE-NON-BREAKING]: Angle Brackets Type Parameters (PARSING) (@jordwalke)[#2604][https://github.com/facebook/reason/pull/2604]

Bug Fixes:

• Fix printing of externals that happen to have newlines/quotes in them (@jordwalke)#2593
• Fix parsing/printing of attributes on patterns (@jordwalke)#2592
• Fix Windows CI (@ManasJayanth) #2611
• Fix uncurry attribute on function application(@anmonteiro) #2566
• Support OCaml 4.11 (@anmonteiro) #2582
• Vendor ocaml-migrate-parsetree for greater compatibility (@jordwalke) #2623

Docs:

• README Reason logo (@iamdarshshah)[#2609][https://github.com/facebook/reason/pull/2609]

3.6.0

New Feature, Non Breaking:

• External syntax: make the external ... = "" part optional (@romanschejbal)#2464

  • external myFn: (string) => unit; is now equivalent to external myFn: (string) => unit = "";

Bug Fixes:

• Fixes issues where method and similar keywords will be transformed to method_ (@cristianoc) #2530

3.5.4

Fixes:

• Fix regression where keywords were not renamed correctly (@cristianoc) #2520
• Fix regression where quoted object attributes / labeled arguments weren't renamed correctly (@anmonteiro) #2509
• Fix issue where JSX braces break into multiple lines (@anmonteiro) #2503

Others:

• Improve bspacks process for 4.06 and add esy workflow for building refmt.js

3.5.3

• 🎉 MUCH better parsing error locations - more reliable autocomplete 🎉 (@let-def)[https://github.com/let-def] (#2439)
• Rebased the better error recovery diff onto 4.09 OCaml @anmonteiro (#2480)
• Fix printing of fragments inside JSX props @anmonteiro (#2463)
• Modernize CI based on latest hello-reason CI @jordwalke (#2479)
• Fix bug that caused necessary braces to be removed @anmonteiro (#2481)
• Make prepublish script auto-generate opam files @jordwalke (#2468)
• Fix brace removal with pipe-first in JSX attributes @bloodyowl (#2474)
• CI Improvements @ulrikstrid (#2459)
• Make sure you can still include rtop from inside utop @sync (#2466)

3.5.2

• Support OCaml 4.09 (2450).
• Improve opam packaging config (2431).
• Improve repo to support esy resolutions to master branch (31225fc0

3.5.0

Improvements:

• Support OCaml 4.08 (2426).

Fixes:

• Print attributes in class fields 2414.
• Preserve function body braces when Pexp_fun is an argument to a function commit
• Prettify try to hug braces 2378
• Fix operator swap for type declarations commit
• Fix JSX removing semicolons commit
• Better formatting of Pexp_lazy commit

3.4.2

Not released to @esy-ocaml/reason - would have required a major version bump. These features will be released in 3.5.0.

Improvements:

• Parse and print parentheses around inline record declarations (2363)
• Proper outcome printing (for editor and build) of inline records (2336)
• Proper outcome printing of types with inline records (parentheses) (2370)

3.4.1

Fixes:

• Don't remove semis in blocks inside ternary expressions as jsx children (2352).
• Handle single line comments ending with end-of-file (2353).

3.4.0

Fixes:

• Don't pun record types if they contain attributes (2316).

Improvements:

• // line comments! (2268). Make sure that your constraints on refmt versions for native projects. Specify a version >= 3.4.0 if you use // comments in your Reason code. Specifiy ranges like 3.4.0-3.5.0.
• Better whitespace interleaving (1990).
• Allow Reason to be used with Merlin Natively on Windows (2256).
• Improved Ternary Formatting (2294).

3.3.4

Fixes:

• Pipe first braces (2133, 2148).
• Better rtop use directives (2146, 2147).
• foo(~Foo.a) becoming foo(~Fooa=Foo.a) (2136).
• Parse <div> ...c</div> correctly (2137).
• Invalid formatting of first-class module with type constraint (2151).
• Precedence printing of pipe first with underscore sugar as JSX child (2159).
• Correct location for JSX name & extension expression (2166, 2162).
• Lack of space after module type of (2175).
• Outcome printer (editor & interface generator) function signature (2185).
• Precedence issue with unary operators and labeled arguments (2201).
• Type printing of polymorphic variants row fields (2191).
• Pattern parsing inside ternary expressions (2188).

Improvements:

• Preserve empty lines in records and bs objects (2152).
• Make let not = blabla work (not is a keyword) (2197).
• Format doc comments on variant leafs with consistency (2194)
• Single pipe first printing layout (2193).
• Performance. One case where the printer took exponential time (2195).

3.3.3

• More fixes for pipe first (2120, 2119, 2111).
• Fix regressed printing of first-class module (2124).
• Fix local open printing for bs.obj (2123).
• fix printing of foo[(bar + 1)] to foo[bar + 1] (2110).
• Only wrap fun in parentheses when necessary (2033).
• Change all precedence printing to braces for consistency inside JSX (2106).
• Format docblock comments above std attrs on record rows (2105).

3.3.2

Big release! No breaking change. Big shout out to @anmonteiro and @iwanKaramazow!

Major:

• Pipe first |. now got a Reason sugar, ->, with better precedence support than the former (1999, 2078, 2092, 2082, 2087, 2055).
• ReasonReact JSX PPX DOM children spread (2095).
• ReasonReact JSX PPX fragment (2091).
• Other ReasonReact JSX PPX fixes (2088, 2060, 2027, 2024, 2007, 2021, 1963).
• Semicolon relaxation & reporting improvements (2040, 2012, 1968).
• Module parsing & formatting improvements (2061, 2059, 1984, 1949, 1946, 2062).
• Remove extra space in some places after formatting (2047, 2041, 1969, 1966, 2097).
• Much better ... spread errors for everything (1973).
• Fix foo##bar[baz], foo->bar^##baz and other precedences (2050, 2055, 2044, 2044).
• Milder "unknown syntax error" message (1962).

Others:

• Parentheses hugging for multi-line Js.t({foo: bar}) (2074).
• Correctly parse prefix ops in labeled parameters (2071).
• Attach doc attributes before extension sugar (2069).
• Support non-parenthesized label colon type equal optional in type declarations (2058).
• Printf uncurried application when last argument is a callback (2064).
• OCaml rtop syntax printing( 2031).
• Fix Bigarray syntax (2045).
• Parse M.[] (2043).
• Fix printing of polymorphic variant with annotation (2019).
• Format GADT type variants better (2016).
• Better autocomplete for Merlin (1998).
• Print newline after doc comments before attributes (1869).
• Fix inconsistent printing of opening extension expressions (1979).
• Fix error when parsing let x=-.1; and others (1945).
• Arguments no longer accidentally punned when they carry attributes (1955).

3.2.0

See the blog post here.

• WHITESPACES IMPROVEMENTS ARE HERE: empty lines between most things will now be preserved when you format your code! Multiple lines still collapse to one line in most cases (1921, 1919, 1876).
• Semicolon relaxation: see blog post (1887).
• Fix parsing & printing of es6 function syntax inside attributes (1943).
• List spread now has better error (1925).
• Functor in JSX tags (1927).
• Better comment printing (1940, 1934).
• Various other printer improvements.

3.1.0

• New pipe sugar for function call argument in arbitrary position: foo |> map(_, addOne) |> filter(_, isEven) (1804).
• BuckleScript [@bs] uncurry sugar: [@bs] foo(bar, baz) is now foo(. bar, baz). Same for declaration (1803, 1832).
• Trailing commas for record, list, array, and everything else (1775, 1821)!
• Better comments interleaving (1769, 1770, 1817)
• Better JSX printing: <Foo bar=<Baz />>, <div><span></span></div> (1745, 1762).
• switch now mandates parentheses around the value. Non-breaking, as we currently support parentheses-less syntax but print parens (1720, 1733).
• Attributes on open expressions (1833).
• Better OCaml 4.06 support (1709).
• Extension points sugar: let%foo a = 1 (1703)!
• Final expression in a function body now also has semicolon. Easier to add new expressions afterward now (1693)!
• Better editor printing (outcome printer) of Js.t object types, @bs types, unary variants and infix operators (1688, 1784, 1831).
• Parser doesn't throw Location.Error anymore; easier exception handling when refmt is used programmatically (1695).

3.0.4

• Default print width is now changed from 100 to 80 (1675).
• Much better callback formatting (1664)!
• Single argument function doesn't require wrapping the argument with parentheses anymore (1692).
• Printer more lenient when user writes [%bs.obj {"foo": bar}]. Probably a confusion with just {"foo": bar} (1659).
• Better formatting for variants constructors with attributes (1668, 1677).
• Fix exponentiation operator printing associativity (1678).

3.0.2

• JSX: fix most of the parsing errors (#856 #904 1181 1263 1292)!! Thanks @IwanKaramazow!
• In-editor syntax error messages are now fixed! They should be as good as the terminal ones (1654).
• Polymorphic variants can now parse and print `foo(()) as `foo() (1560).
• Variant values with annotations like Some((x: string)) can now be Some(x: string) (1576).
• Remove few places remaining that accidentally print fun for functions (1588).
• Better record & object printing (1593, 1596).
• Fewer unnecessary wrappings in type declarations and negative constants (1616, 1634).
• Parse and print attributes on object type rows (1637).
• Better printing of externals with attributes (1640).
• Better printing for multiple type equations in a module type in a function argument (1641).
• Better printing for unary -. in labeled argument (1642).

3.0.0

Our biggest release! Please see our blog post on https://reasonml.github.io/blog/2017/10/27/reason3.html.

Summary: this is, practically speaking, a non-breaking change. You can mix and match two projects with different syntax versions in BuckleScript 2 (which just got release too! Go check), and they'll Just Work (tm).

To upgrade your own project, we've released a script, https://github.com/reasonml/upgradeSyntaxFrom2To3

Improvements:

• Much better printing for most common idioms.
• Even better infix operators formatting for ==, &&, > and the rest (1380, 1386, etc.).
• More predictable keyword swapping behavior (1539).
• BuckleScript's Js.t {. foo: bar} now formats to {. "foo": bar}, just like its value counterpart ([%bs.obj {foo: 1}] to {"foo": bar}.
• [@foo], [@@foo] and [@@@foo] are now unified into [@foo] and placed in front instead of at the back.
• ! is now the logical negation. It was not previously.
• Dereference was !. Now it's a postfix ^.
• Labeled argument with type now has punning!
• String concat is now ++ instead of the old ^.
• For native, Reason now works on OCaml 4.05 and the latest topkg (1438).
• Record field punning for module field prefix now prints well too: {M.x, y} is {M.x: x, y: y}.
• JSX needs {} like in JS.
• Fix reason-specific keywords printing in interface files (e.g. ==, match, method).
• Record punning with renaming (1517).
• The combination of function label renaming + type annotation + punning is now supported!
• Label is now changed from ::foo back to ~foo, just like for OCaml.
• Fix LOTS of bugs regarding parsing & formatting (closing around 100 improvement-related issues!).
• Official refmt.js, with public API. See README.md.
• Official refmt native public API too.
• New JS application/abstraction syntax. Yes yes, we know. Despite the 100+ fixes, this one's all you cared about. Modern software engineering ¯\_(ツ)_/¯. Please do read the blog post though.

Breaking Changes:

• Remove --use-stdin and --is-interface-pp option from refmt; they've been deprecated for a long time now
• Remove unused binaries: reup, etc.
• Remove the old reactjs_jsx_ppx.ml. You've all been on reactjs_jsx_ppx_2.ml for a long time now.
• Reserved keywords can no longer be used as an external declaration's labels.

Deprecated:

• Deprecate --add-printers option from refmt; we'll have a better strategy soon.

1.13.7

• Much better infix operators (e.g. |>) formatting! (1259)
• Official refmt.js, with public API. See README.md. We've back-ported this into the 1.13.7 release =)

1.13.6

• Changelog got sent into a black hole