## Fourmolu 0.17.0.0

* Add new `import-grouping` option to group imports with grouping rules specified in configuration ([#403](https://github.com/fourmolu/fourmolu/pull/403))

* Add new `sort-constraints` option to sort constraints alphabetically ([#433](https://github.com/fourmolu/fourmolu/pull/433))

* Add new `sort-derived-classes` option to sort classes in deriving clauses ([#434](https://github.com/fourmolu/fourmolu/pull/434))

* Add new `sort-derived-clauses` option to sort classes deriving clauses ([#434](https://github.com/fourmolu/fourmolu/pull/434))

* Add new `trailing-section-operators` option to disable trailing "section" operators (those that are `infixr 0`, such as `$`) ([#444](https://github.com/fourmolu/fourmolu/pull/444))

* Fix issue where `single-constraint-parens: never` would drop parentheses around implicit parameters ([#446](https://github.com/fourmolu/fourmolu/issues/446))

* Fix indentation for parenthesized expressions that start off the indentation column ([#428](https://github.com/fourmolu/fourmolu/issues/428))

* Allow multiline comments in indented contexts ([#65](https://github.com/fourmolu/fourmolu/issues/65))


## Fourmolu 0.16.2.0

### Upstream changes:

#### Ormolu 0.7.7.0

* Use single-line layout for parens around single-line content. [Issue
  1120](https://github.com/tweag/ormolu/issues/1120).

* Allow function arguments to be on the same line even if the full type
  (with constraints and foralls) are on multiple lines. [PR
  1125](https://github.com/tweag/ormolu/pull/1125).

## Fourmolu 0.16.1.0

### Upstream changes:

#### Ormolu 0.7.6.0

* Fix Haddock comments on infix constructors
  [Issue 758](https://github.com/tweag/ormolu/issues/758).

* Don't require a trailing newline in `.ormolu` files. [Issue
  1122](https://github.com/tweag/ormolu/issues/1122).

* Remove unnecessary indentation from list comprehensions. [Issue
  966](https://github.com/tweag/ormolu/issues/966).

## Fourmolu 0.16.0.0

* Allow specifying path to configuration file with `--config` ([#396](https://github.com/fourmolu/fourmolu/issues/396))

### Upstream changes:

#### Ormolu 0.7.5.0

* Switched to `ghc-lib-parser-9.10`, with the following new syntactic features/behaviors:
  * GHC proposal [#575](https://github.com/ghc-proposals/ghc-proposals/blob/10290a668608d608c3f6c6010be265cf7a02e1fc/proposals/0575-deprecated-instances.rst): deprecated instances.
  * GHC proposal [#281](https://github.com/ghc-proposals/ghc-proposals/blob/10290a668608d608c3f6c6010be265cf7a02e1fc/proposals/0281-visible-forall.rst): visible forall in types of terms.
    Enabled by `RequiredTypeArguments` (enabled by default).
  * `LinearTypes`: `let` and `where` bindings can now be linear, in particular have multiplicity annotations.
  * Using `forall` as an identifier is now a parse error.
  * GHC proposal [#65](https://github.com/ghc-proposals/ghc-proposals/blob/10290a668608d608c3f6c6010be265cf7a02e1fc/proposals/0065-type-infix.rst): namespacing fixity declarations for type names and WARNING/DEPRECATED pragmas.
  * `TypeAbstractions` now supports `@`-binders in lambdas and function equations.
  * Support for the `GHC2024` language.

* Updated to `Cabal-syntax-3.12`.

## Fourmolu 0.15.0.0

* Add `single-deriving-parens` configuration option to determine if `deriving` clauses of a single type should be parenthesized ([#386](https://github.com/fourmolu/fourmolu/pull/386))

* Fix the order in which the configurations are applied ([#390](https://github.com/fourmolu/fourmolu/issues/390))

### Upstream changes:

#### Ormolu 0.7.4.0

* Don't error when the `JavaScriptFFI` language pragma is present. [Issue
  1087](https://github.com/tweag/ormolu/issues/1087).
* Improve comment placement in if-then-else blocks. [Issue
  998](https://github.com/tweag/ormolu/issues/998).
* Now command line options for fixity overrides and module re-exports
  overwrite information from `.ormolu` files. [Issue
  1030](https://github.com/tweag/ormolu/issues/1030).
* Respect newlines in data declarations in more cases. [Issue
  1077](https://github.com/tweag/ormolu/issues/1077) and [issue
  947](https://github.com/tweag/ormolu/issues/947).
* The `-d / --debug` command line option now makes Ormolu print out debug
  information regarding operator fixity inference. [Issue
  1060](https://github.com/tweag/ormolu/issues/1060).

## Fourmolu 0.14.1.0

* Fix `single-constraint-parens: never` for nested quantified constraints ([#374](https://github.com/fourmolu/fourmolu/issues/374))

* Fix `column-limit` with `BlockArguments` ([#377](https://github.com/fourmolu/fourmolu/issues/377))

* Fixed an issue where re-exporting a module with Haddock comments + `import-exports=leading` was indented too far ([#381](https://github.com/fourmolu/fourmolu/issues/381))

### Upstream changes:

#### Ormolu 0.7.3.0

* Switched to `ghc-lib-parser-9.8`, with the following new syntactic features:
  * `ExtendedLiterals`: `123#Int8` is a literal of type `Int8#`. (disabled by
    default)
  * `TypeAbstractions`: `@k`-binders in data type declarations (enabled by
    default)
  * GHC proposal [#134](https://github.com/ghc-proposals/ghc-proposals/blob/0b652bd70258e354dfe4a05940182007596f8bf7/proposals/0134-deprecating-exports-proposal.rst): deprecating/warning about exports
  * GHC proposal [#541](https://github.com/ghc-proposals/ghc-proposals/blob/0b652bd70258e354dfe4a05940182007596f8bf7/proposals/0541-warning-pragmas-with-categories.rst): warning categories

## Fourmolu 0.14.0.0

* Provide `resolvePrinterOpts` instead of `fillMissingPrinterOpts`

* Format configuration better in `--debug` output

### Upstream changes:

#### Ormolu 0.7.2.0

* Preserve necessary braces for final function arguments. [Issue
  1044](https://github.com/tweag/ormolu/issues/1044).

* Put `"this"` `PackageImports` at the end. [Issue
  1048](https://github.com/tweag/ormolu/issues/1048).

* Format parenthesized operators starting with a `#` correctly in the presence
  of `UnboxedSums`. [Issue 1062](https://github.com/tweag/ormolu/issues/1062).

* Fix false positives in AST diffing related to empty Haddock comments in data
  declarations. [Issue 1065](https://github.com/tweag/ormolu/issues/1065).

## Fourmolu 0.13.1.0

* Fix `single-constraint-parens: never` with `QuantifiedConstraints` ([#340](https://github.com/fourmolu/fourmolu/issues/340))
* Fix issue with single documented export + `import-export-style: leading` ([#341](https://github.com/fourmolu/fourmolu/issues/341))
* Fix reexports configuration not allowing repeated modules ([#336](https://github.com/fourmolu/fourmolu/issues/336))

## Fourmolu 0.13.0.0

* Automatically ignore files in Cabal/Stack directories when recursively finding files to format.

### Upstream changes:

#### Ormolu 0.7.1.0

* Include `base` fixity information when formatting a Haskell file that's
  not mentioned in an existing cabal file. [Issue
  1032](https://github.com/tweag/ormolu/issues/1032)

* Update `displayException` for `OrmoluException` to pretty print the
  exception. [PR 1031](https://github.com/tweag/ormolu/pull/1031).

* Ormolu is now aware of more common module re-exports by default.

* Support explicit mention of target package name in module re-exports. Even
  if the exported package is not specified as a direct dependency of the
  component being formatted it will still be taken into account correctly.
  [Issue 1037](https://github.com/tweag/ormolu/issues/1037).

* Ormolu no longer fails when CPP directly follows the import section (a
  regression introduced in 0.7.0.0). [Issue
  1040](https://github.com/tweag/ormolu/issues/1040).

#### Ormolu 0.7.0.0

* Inference of operator fixity information is now more precise and takes
  into account the import section of the module being formatted. [Issue
  892](https://github.com/tweag/ormolu/issues/892) and [issue
  929](https://github.com/tweag/ormolu/issues/929).

* Ormolu can now be made aware of module re-exports through ~~either special
  declarations in `.ormolu` files~~ the `reexports` configuration option (see the readme for a description of the
  syntax), or on the command line with the `--reexport`/`-r` option. [Issue
  1017](https://github.com/tweag/ormolu/issues/1017).

* ~~Ormolu now looks for `.ormolu` files independently of `.cabal` files. This
  means that it is now possible to have one `.ormolu` file for multiple
  Cabal packages. [Issue 1019](https://github.com/tweag/ormolu/issues/1019).~~

* Consistently format `do` blocks/`case`s/`MultiWayIf`s with 4 spaces if and
  only if they occur as the applicand. [Issue
  1002](https://github.com/tweag/ormolu/issues/1002) and [issue
  730](https://github.com/tweag/ormolu/issues/730).

* Support the (deprecated) `DatatypeContexts` extension to avoid surprises.
  [Issue 1012](https://github.com/tweag/ormolu/issues/1012).

* Don't let comments escape from empty export lists. [Issue
  906](https://github.com/tweag/ormolu/issues/906).

* Format `\cases` with multiple patterns across multiple lines correctly. [Issue
  1025](https://github.com/tweag/ormolu/issues/1025).

## Fourmolu 0.12.0.0

* Add `single-constraint-parens` option for controlling parenthesis around constraints in type
  signatures. See [issue 288](https://github.com/fourmolu/fourmolu/pull/304)

* Add `column-limit` option to try to insert line breaks when lines exceed a certain length.
  May break idempotence in some particularly painful cases.
  See [issue 71](https://github.com/fourmolu/fourmolu/pull/305)

* Add a new CLI flag `--print-defaults` which makes fourmolu print default options to stdout.
  This can be used to generate default config which can be further tweaked by user `fourmolu --print-defaults > fourmolu.yaml`.
  See [issue 307](https://github.com/fourmolu/fourmolu/pull/308)

### Upstream changes:

#### Ormolu 0.6.0.1

* Fix false positives in AST diffing related to `UnicodeSyntax`. [PR
  1009](https://github.com/tweag/ormolu/pull/1009).

#### Ormolu 0.6.0.0

* Haddocks attached to arguments of a data constructor are now formatted in
  the pipe style (rather than the caret style), consistent with everything
  else. As a consequence, now Ormolu's output will be deemed invalid by the
  Haddock shipped with GHC <9.0. [Issue
  844](https://github.com/tweag/ormolu/issues/844) and [issue
  828](https://github.com/tweag/ormolu/issues/828).

* Insert space before char literals in ticked promoted constructs when
  necessary. [Issue 1000](https://github.com/tweag/ormolu/issues/1000).

* Switched to `ghc-lib-parser-9.6`:
  * Extended `OverloadedLabels`: `#Foo`, `#3`, `#"Hello there"`.

    Also, it is now disabled by default, as it causes e.g. `a#b` to be parsed
    differently.
  * New extension: `TypeData`, enabled by default.
  * Parse errors now include error codes, cf. https://errors.haskell.org.

* Updated to `Cabal-syntax-3.10`.

* Now whenever Ormolu fails to parse a `.cabal` file it also explains why.
  [PR 999](https://github.com/tweag/ormolu/pull/999).

## Fourmolu 0.11.0.0

* Added the `no-space` value for the `in-style` option. See [issue
  291](https://github.com/fourmolu/fourmolu/291)

### Upstream changes:

#### Ormolu 0.5.2.0

* Eliminated the `fixity-th` Cabal flag because it caused issues on GHC 9.4 as
  well as on aarch64. See [issue
  941](https://github.com/tweag/ormolu/issues/941) and [issue
  927](https://github.com/tweag/ormolu/issues/927).

* Now operators without explicitly specified fixity default to left
  associativity and highest precedence. [Issue
  907](https://github.com/tweag/ormolu/issues/907).

#### Ormolu 0.5.3.0

* Stop making empty `let`s move comments. [Issue
  917](https://github.com/tweag/ormolu/issues/917).

* Now `.ormolu` fixity override files can use both LF and CRLF line endings.
  [PR 969](https://github.com/tweag/ormolu/pull/969).

* Normalize parentheses around constraints. [Issue
  264](https://github.com/tweag/ormolu/issues/264).

* The `ormolu` function now consumes `Text` instead of `String` due to an
  internal refactoring.

* Exposed a more complete public API in the `Ormolu` module. The API is
  supposed to be stable and change according to
  [PVP](https://pvp.haskell.org/).

* Now warnings regarding Ormolu not being able to find `.cabal` files or
  finding such files but them not mentioning the source file in question are
  only displayed when `--debug` is used. Printing the warnings by default
  seems to have been confusing, see e.g. [Issue
  971](https://github.com/tweag/ormolu/issues/971) and [issue
  924](https://github.com/tweag/ormolu/issues/924).

## Fourmolu 0.10.1.0

* Fix bug where using `{-` in a single-line comment would wrongfully escape it ([#265](https://github.com/fourmolu/fourmolu/issues/265))
* Fix idempotence bug with indented multiline comments ([#273](https://github.com/fourmolu/fourmolu/issues/273))

## Fourmolu 0.10.0.0

New options:

* New `leading-args` option to `function-arrows` configuration that allows leading arrows only for function arguments ([#233](https://github.com/fourmolu/fourmolu/issues/233))
* Add `haddock-style-module` option ([#135](https://github.com/fourmolu/fourmolu/pull/135))

Improvements of existing options:

* Add unicode formatting for quasiquotes and arrow brackets ([#261](https://github.com/fourmolu/fourmolu/pull/261))

Bug fixes:

* Fix bug with `let-style` changing single-line let-in blocks in `do` blocks to multiline.
* Don't consider the first space after `--` part of the comment ([#255](https://github.com/fourmolu/fourmolu/pull/255))

### Upstream changes:

#### Ormolu 0.5.1.0

* Imports are now sorted by package qualifier, if one is present.
  [Issue 905](https://github.com/tweag/ormolu/issues/905).

* Extension packs like `GHC2021` and `Haskell2010` are now bumped to the top of
  the list of language pragmas. [Issue
  922](https://github.com/tweag/ormolu/issues/922).

* Fix formatting of `SCC` pragmas in `do` blocks. [Issue
  925](https://github.com/tweag/ormolu/issues/925).

* Support type applications in patterns. [Issue
  930](https://github.com/tweag/ormolu/issues/930).

* Handle `UnicodeSyntax` variants more consistently. [Issue
  934](https://github.com/tweag/ormolu/issues/934).

* Fix an inconsistency in formatting of types in GADT declarations in
  certain cases. [PR 932](https://github.com/tweag/ormolu/pull/932).

* Switched to `ghc-lib-parser-9.4`, which brings support for the following new
  syntactic features:
  * `\cases` via `LambdaCase`
  * `OPAQUE` pragmas
  * Unboxed sum type constructors like `(# | #)`.

* Updated to `Cabal-syntax-3.8`, supporting `cabal-version: 3.8`.

## Fourmolu 0.9.0.0

New configuration options:

* Add `let-style` and `in-style` configuration options ([#229](https://github.com/fourmolu/fourmolu/pull/229)). The default is set to `let-style: auto` and `in-style: right-align`, which should not reformat already formatted files _(with some exceptions depending on comment placement)_, but allows users to format with `newline` without additional configuration.
* Add `unicode` configuration ([#206](https://github.com/fourmolu/fourmolu/pull/206))

Bug fixes:

* Fix some edge cases with function arrows ([#247](https://github.com/fourmolu/fourmolu/pull/247))
* Fix formatting of module header + export lists when `WARNING` or `DEPRECATED` pragma is present ([#244](https://github.com/fourmolu/fourmolu/pull/244))
* Fixed a bug where an extra space was inserted before promoted types (e.g. `foo @'True`) ([#211](https://github.com/fourmolu/fourmolu/pull/211))
* When `--respectful` is enabled, a `where` keyword on the line after the export list will not be moved up to the end of the previous line. ([#167](https://github.com/fourmolu/fourmolu/issues/167))

## Fourmolu 0.8.2.0

* Add `multi-line-compact` option to `haddock-style` that will output `{-|` for multiline haddocks instead of `{- |` ([#130](https://github.com/fourmolu/fourmolu/pull/130))
* Add `function-arrows` configuration option to style arrow placement in type signatures ([#209](https://github.com/fourmolu/fourmolu/pull/209))

## Fourmolu 0.8.1.0

* Add `emptyConfig` ([#221](https://github.com/fourmolu/fourmolu/pull/221))
* Fixed CLI options not overriding config file options, broken in 0.7.0.0 ([#225](https://github.com/fourmolu/fourmolu/pull/225))

## Fourmolu 0.8.0.0

* Consolidate `import-export-comma-style` and `diff-friendly-import-export` into a new option `import-export-style` ([#201](https://github.com/fourmolu/fourmolu/pull/207))
* Accept folders as input ([#213](https://github.com/fourmolu/fourmolu/issues/213))

### Upstream changes:

#### Ormolu 0.5.0.1

* Fixed a bug in the diff printing functionality. [Issue
  886](https://github.com/tweag/ormolu/issues/886).

* Indent closing bracket for list comprehensions in `do` blocks.
  [Issue 893](https://github.com/tweag/ormolu/issues/893).

* Fix `hs-source-dirs: .` resulting in failing to find a `.cabal` file for a
  Haskell source file. [Issue 909](https://github.com/tweag/ormolu/issues/909).

* Comments in closed type family declarations are now indented correctly.
  [Issue 913](https://github.com/tweag/ormolu/issues/913).

* Cache `.cabal` file parsing and processing when given multiple input files in
  the same project. This results in dramatic speedups on projects which have
  both huge `.cabal` files and a large number of individual modules. [Issue
  897](https://github.com/tweag/ormolu/issues/897).

## Fourmolu 0.7.0.1

* Fix bad copy/paste where parsing errors for `haddock-style` would mention `CommaStyle`
* Include relevant test files in sdist bundle

## Fourmolu 0.7.0.0

* Add `--quiet` flag to make the output quieter
* Removed `--cabal-default-extensions` flag; the behavior is now enabled by default
* Add `fixities` configuration to `fourmolu.yaml`
  * See the notes in the Ormolu changelog below, except instead of providing fixity information in a `.ormolu` file, it should be in a `fixities` config option in `fourmolu.yaml`, e.g.

  ```yaml
  fixities:
    - 'infixr 8 .='
    - 'infixr 5 #'
  ```
* Fixed issue with `import-export-comma-style` for multiline import/export elements ([#187](https://github.com/fourmolu/fourmolu/pull/187))
* Multiline haddock comments with consecutive empty newlines will no longer report an "AST differs" error ([#172](https://github.com/fourmolu/fourmolu/issues/172))

### Upstream changes:

#### Ormolu 0.5.0.0

* Changed the way operator fixities and precedences are inferred.
  * Ormolu now tries to locate `.cabal` files of source files by default and
    in addition to default extensions it also infers the list of
    dependencies.
  * Ormolu comes equipped with extensive knowledge of all packages on
    Hackage and operators that those packages define. Knowing the names of
    the dependencies it can select the right fixity and precedence info from
    its knowledge base.
  * You can ask Ormolu not to look for `.cabal` files by using the
    `--no-cabal` switch.
  * Dependencies can be selected manually by using the `-p / --package`
    option (can be repeated many times).
  * The default heuristic algorithm will still try to guess the right
    fixities and precedence.
  * ~Fixity overrides can be provided by the user in the familiar Haskell
    notation (e.g. `infixr 9 .`, one declaration per line). They are loaded
    by default from the `.ormolu` file that is expected to be in the same
    directory as the `.cabal` file of a given source file. However, if
    `--no-cabal` is supplied, the `.ormolu` file will not be looked for either.~
    Fixity declarations can be also provided by using the `-f / --fixity`
    command line option, which see.
  * This resolves the following issues: [Issue
    826](https://github.com/tweag/ormolu/issues/826), [Issue
    785](https://github.com/tweag/ormolu/issues/785), [Issue
    690](https://github.com/tweag/ormolu/issues/690), [Issue
    825](https://github.com/tweag/ormolu/issues/825).

* Invalid haddock comments are formatted in a more consistent way. Leading
  haddock triggers (`|`, `^`) in an invalid haddock comment block are now
  escaped with a backslash `\`. [Issue
  816](https://github.com/tweag/ormolu/issues/816).

* Type synonyms and families are now formatted correctly when the equals sign
  is preceded by a comment. [Issue 829](
  https://github.com/tweag/ormolu/issues/829).

* Bidirectional pattern synonyms are formatted nicer in certain cases.
  [Issue 843](https://github.com/tweag/ormolu/issues/843).

* Magic comments (like `{- ORMOLU_DISABLED -}`) now allow arbitrary
  succeeding text. This fixes use cases like [Issue
  856](https://github.com/tweag/ormolu/issues/856).

* Remove discrepancies between unboxed types and terms. [Issue 856
  ](https://github.com/tweag/ormolu/issues/856).
  * Unboxed sum types are now formatted with a space before each `|`.
  * Unboxed unit tuples on type and value levels are formatted as `(# #)`.

* Errors caused by AST differences now print before/after diffs.
  [Issue 877](https://github.com/tweag/ormolu/issues/877).

* Improved formatting of data declarations in the case of single-constructor
  record with a Haddock. [Issue
  881](https://github.com/tweag/ormolu/issues/881).

## Fourmolu 0.6.0.0

* Fixed regression in 0.5.0.0 with multiline tuples ([#162](https://github.com/fourmolu/fourmolu/pull/162))
* Fixed regression in 0.5.0.0 with multiline record types ([#160](https://github.com/fourmolu/fourmolu/pull/160))
* Fixed regression in 0.5.0.0 with indentation after a list comprehension ([#149](https://github.com/fourmolu/fourmolu/pull/149))
* Add `import-export-comma-style` configuration to allow leading commas in module import/export lists

## Fourmolu 0.5.0.0

* Fixed issue with leading commas in guards ([#123](https://github.com/fourmolu/fourmolu/pull/123))
* Use trailing haddocks for record fields when using leading commas ([#124](https://github.com/fourmolu/fourmolu/pull/124))

### Upstream changes:

#### Ormolu 0.4.0.0

* When a guard is located on its own line, the body associated with this
  guard is indented by one extra level, so that it can easily be
  distinguished from the guard predicate or pattern. [Issue
  806](https://github.com/tweag/ormolu/issues/806).

* Now a space is forced after `--` in line comments. [Issue
  808](https://github.com/tweag/ormolu/issues/808).

* Allow formatting Backpack signature files (`.hsig`). The switch between
  regular module mode and signature mode is based on the file extension by
  default, but can be overridden with the `-t / --source-type` command line
  option. [Issue 600](https://github.com/tweag/ormolu/issues/600).

* Blank Haddock comments are now eliminated. This also fixes issues with
  differing ASTs in some special cases. [Issue
  726](https://github.com/tweag/ormolu/issues/726).

* Rewrite rules that are never active are now formatted correctly.
  [Issue 823](https://github.com/tweag/ormolu/issues/823).

* Promoted infix data constructors are now formatted correctly. [Issue 768](
  https://github.com/tweag/ormolu/issues/768).

* Switched to `ghc-lib-parser-9.2`.
  [Issue 794](https://github.com/tweag/ormolu/issues/794).
   * Support for the new syntax-related language extensions:
     `OverloadedRecordDot` and `OverloadedRecordUpdate`
     (disabled by default).
     [Issue 709](https://github.com/tweag/ormolu/issues/709).
   * Removed support for `record-dot-preprocessor`. For the getter syntax,
     consider using `OverloadedRecordDot` instead. [Issue
     659](https://github.com/tweag/ormolu/issues/659). [Issue
     705](https://github.com/tweag/ormolu/issues/705).
   * Support for the `GHC2021` language.

#### Ormolu 0.3.1.0

* Allow check mode when working with stdin input. [Issue 634](
  https://github.com/tweag/ormolu/issues/634).

* Now guards are printed on a new line if at least one guard is multiline or
  if all guards together occupy more than one line. The body of each guard
  is also indented one level deeper in that case. [Issue
  712](https://github.com/tweag/ormolu/issues/712).

* Invalid Haddock comments are no longer silently deleted, but rather converted
  into regular comments. [Issue 474](https://github.com/tweag/ormolu/issues/474).

## Fourmolu 0.4.0.0

* Write "Loaded config from" message to `stderr` instead of `stdout` ([#42](https://github.com/fourmolu/fourmolu/pull/42))
* Fixed issue with multiline haddocks in indented contexts ([#64](https://github.com/fourmolu/fourmolu/pull/64))
* Avoid renaming magic comments ([#90](https://github.com/fourmolu/fourmolu/pull/90))

### Upstream changes:

#### Ormolu 0.3.0.1

* Improvements to `.cabal` file handling:
   * When looking for a `.cabal` file, directories were previously
     erroneously also considered. [Issue 781](
     https://github.com/tweag/ormolu/issues/781).
   * We now print a note if Ormolu was told to consider
     `.cabal` files, but no suitable one could be found.
   * Handle an empty `hs-source-dirs` correctly.
   * Also consider modules which are only conditionally listed
     in the `.cabal` file.

* The special handling of CPP is now only applied if CPP is
  actually enabled. [Issue 782](https://github.com/tweag/ormolu/issues/782).

* The left hand side of the `:` operator now uses braces if
  necessary. [Issue 780](https://github.com/tweag/ormolu/issues/780).

#### Ormolu 0.3.0.0

* Data declarations with multiline kind signatures are now formatted
  correctly. [Issue 749](https://github.com/tweag/ormolu/issues/749).

* Infix arrow command formations are formatted like usual operators.
  This fixes [Issue 748](https://github.com/tweag/ormolu/issues/748).

* `do` arrow commands are formatted more flexibly. Fixes [Issue
  753](https://github.com/tweag/ormolu/issues/753).

* Source code is always read and written using UTF8 and ignoring the native
  line ending conventions. [Issue
  717](https://github.com/tweag/ormolu/issues/717).

* Opt-in support to respect default-extensions and default-language
  from .cabal files. [Issue 517](https://github.com/tweag/ormolu/issues/517).

* Empty case expressions are now rendered with braces. [Issue
  765](https://github.com/tweag/ormolu/issues/765).

* Omit braces on repeated application of `do` blocks. [Issue
  735](https://github.com/tweag/ormolu/issues/735).

* Improved handling of disabled regions. [PR 773](
  https://github.com/tweag/ormolu/pull/773).
   * Disabled regions are now exactly preserved, in particular
     empty lines and trailing spaces. [Issue
     673](https://github.com/tweag/ormolu/issues/673).
   * Strings like `-}` can now be present in disabled regions.
     [Issue 708](https://github.com/tweag/ormolu/issues/708).

  This means that using CPP or magic comments in certain ways which
  were only supported as a side effect previously (like in
  [Issue 601](https://github.com/tweag/ormolu/issues/601))
  will now result in formatting failures. Also see [Issue 774](
  https://github.com/tweag/ormolu/issues/774).

#### Ormolu 0.2.0.0

* Now standalone kind signatures are grouped with type synonyms. [Issue
  683](https://github.com/tweag/ormolu/issues/683).

* `TemplateHaskell` is not enabled by default anymore. [Issue
  699](https://github.com/tweag/ormolu/issues/699).

* Made record dot pre-processor rendering idempotent in certain specific
  cases. [Issue 701](https://github.com/tweag/ormolu/issues/701).

* Added support for arrow command application. [Issue
  716](https://github.com/tweag/ormolu/issues/716).

* Switched to `ghc-lib-parser-9.0.1`. [PR
  722](https://github.com/tweag/ormolu/pull/722).
   * Support for the new language extensions:
      * `LexicalNegation`, `LinearTypes`: disabled by default
      * `QualifiedDo`: enabled by default
   * Due to [upstream changes in whitespace sensitity](
     https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.0#whitespace-sensitive-and-),
     `TypeApplications` is now *enabled* by default. [Issue
     452](https://github.com/tweag/ormolu/issues/452).
   * Haddocks on declarations in files without a `module` header are no longer
     deleted. [Issue 480](https://github.com/tweag/ormolu/issues/480).
   * Due to a change in Haddock parsing, empty Haddock comments on function
     arguments now get deleted.

* CTYPE pragmas are now preserved. [Issue 689](
  https://github.com/tweag/ormolu/issues/689).

* `TypeApplications` in data/type family instances are now supported. [Issue
  698](https://github.com/tweag/ormolu/issues/698).

* Formatting infix arrow command formations now preserves the AST. [Issue
  718](https://github.com/tweag/ormolu/issues/718).

* Surround code in brackets with spaces if it contains a `StarIsType` `*` to
  prevent unparseable output. [Issue 704](https://github.com/tweag/ormolu/issues/704).

* Formatting applied multiline constructs in do blocks now preserves the AST.
  [Issue 707](https://github.com/tweag/ormolu/issues/707).

  This will sometimes result in odd indentations, e.g. this snippet is a
  fixed point:
  ```haskell
  foo = do
    do
      (+1)
     1
  ```

* GHC options passed in via the CLI can now be overridden in local files.
  Previously, if an extension was disabled via the CLI, it could not be
  re-enabled per file.

* `NegativeLiterals` is no longer enabled by default. Also, spaces after
  negation via `-` are removed where possible. [Issue
  694](https://github.com/tweag/ormolu/issues/694).

* Minus signs in literal patterns are now preserved in all cases. [Issue
  733](https://github.com/tweag/ormolu/issues/733).

* Added support for left-to-right arrow application. [Issue
  737](https://github.com/tweag/ormolu/issues/737).

* Now `--mode check` fails on missing trailing blank lines. [Issue
  743](https://github.com/tweag/ormolu/issues/743).

* Fixed indentation of arrow forms in do blocks. [Issue
  739](https://github.com/tweag/ormolu/issues/739).

#### Ormolu 0.1.4.1

* Added command line option `--color` to control how diffs are printed.
  Standardized the way errors are printed.

#### Ormolu 0.1.4.0

* Added support for monad comprehensions. [Issue
  665](https://github.com/tweag/ormolu/issues/665).

* Fixed a bug when a space was inserted in front of promoted types even when
  it wasn't strictly necessary. [Issue
  668](https://github.com/tweag/ormolu/issues/668).

* Now the checking mode displays diffs per file when unformatted files are
  found. The rendering of the diffs is also improved. [Issue
  656](https://github.com/tweag/ormolu/issues/656).

#### Ormolu 0.1.3.1

* Fixed a problem with multiline record updates using the record dot
  preprocessor. [Issue 658](https://github.com/tweag/ormolu/issues/658).

## Fourmolu 0.3.0.0

* New config option `newlines-between-decls`, to choose the number of blank lines between top-level declarations.
* Minor CLI improvements. In particular, the set of valid values for each option is communicated more consistently.

## Fourmolu 0.2.0.0

* More consistent indentation. Previously, with indentation set to n, some constructs such as nested lists and tuples would use an ugly mix of n-space and 2-space indentation.

* New configuration options (see README or Hackage docs for details):
  * `comma-style`
  * `record-brace-space`
  * `indent-wheres`
  * `diff-friendly-import-export`
  * `respectful`
  * `haddock-style`

### Upstream changes:

#### Ormolu 0.1.3.0:

* Ormolu no longer overwrites already formatted files. [PR
  649](https://github.com/tweag/ormolu/pull/649).

* Now a space is guaranteed before ticked promoted types. [Issue
  631](https://github.com/tweag/ormolu/issues/631).

* Made formatting of single-line explicitly bidirectional pattern synonyms
  idempotent. [Issue 630](https://github.com/tweag/ormolu/issues/630).

#### Ormolu 0.1.2.0:

* Fixed the bug when comments in different styles got glued together after
  formatting. [Issue 589](https://github.com/tweag/ormolu/issues/589).

* Added `-i` as a shortcut for `--mode inplace`. [Issue
  467](https://github.com/tweag/ormolu/issues/467).

* Improved grouping of top-level declarations. [Issue
  466](https://github.com/tweag/ormolu/issues/466).

## Fourmolu 0.1.1.0

### Upstream changes:

#### Ormolu 0.1.1.0:

* Imports in a import lists are now normalized: duplicate imports are
  combined/eliminated intelligently.

* Import declarations that can be merged are now automatically merged.
  [Issue 414](https://github.com/tweag/ormolu/issues/414).

* The magic comments for disabling and enabling Ormolu now can encompass any
  fragment of code provided that the remaining code after exclusion of the
  disabled part is still syntactically correct. [Issue
  601](https://github.com/tweag/ormolu/issues/601).

* Improved sorting of operators in imports. [Issue
  602](https://github.com/tweag/ormolu/issues/602).

* Fixed a bug related to trailing space in multiline comments in certain
  cases. [Issue 603](https://github.com/tweag/ormolu/issues/602).

* Added support for formatting linked lists with `(:)` as line terminator.
  [Issue 478](https://github.com/tweag/ormolu/issues/478).

* Fixed rendering of function arguments in multiline layout. [Issue
  609](https://github.com/tweag/ormolu/issues/609).

* Blank lines between definitions in `let` and `while` bindings are now
  preserved. [Issue 554](https://github.com/tweag/ormolu/issues/554).

* Fixed the bug when type applications stuck to the `$` of TH splices that
  followed them. [Issue 613](https://github.com/tweag/ormolu/issues/613).

* Improved region formatting so that indented fragments—such as definitions
  inside of `where` clauses—can be formatted. [Issue
  572](https://github.com/tweag/ormolu/issues/572).

* Fixed the bug related to the de-association of pragma comments. [Issue
  619](https://github.com/tweag/ormolu/issues/619).

## Fourmolu 0.1.0.0

* Allow configuration of indentation size via `fourmolu.yaml` config files.

* An operator on a new line is no longer indented when its left operand is a do-block. This prevents the AST from potentially changing when indenting by more than two spaces.

### Upstream changes:

#### Ormolu 0.1.0.0:

* Fixed rendering of type signatures concerning several identifiers. [Issue
  566](https://github.com/tweag/ormolu/issues/566).

* Fixed an idempotence issue with inline comments in tuples and parentheses.
  [Issue 450](https://github.com/tweag/ormolu/issues/450).

* Fixed an idempotence issue when certain comments were picked up as
  “continuation” of a series of comments [Issue
  449](https://github.com/tweag/ormolu/issues/449).

* Fixed an idempotence issue related to different indentation levels in a
  comment series. [Issue 512](https://github.com/tweag/ormolu/issues/512).

* Fixed an idempotence issue related to comments which may happen to be
  separated from the elements they are attached to by the equality sign.
  [Issue 340](https://github.com/tweag/ormolu/issues/340).

* Fixed an idempotence issue with type synonym and data declarations where
  the type has a Haddock. [Issue
  578](https://github.com/tweag/ormolu/issues/578).

* Fix the false positive about AST differences in presence of comments with
  multiple blank lines in a row. [Issue
  518](https://github.com/tweag/ormolu/issues/518).

* Fixed rendering of comments around if expressions. [Issue
  458](https://github.com/tweag/ormolu/issues/458).

* Unnamed fields of data constructors are now documented using the `-- ^`
  syntax. [Issue 445](https://github.com/tweag/ormolu/issues/445) and [Issue
  428](https://github.com/tweag/ormolu/issues/428).

* Fixed non-idempotent transformation of partly documented data definition.
  [Issue 590](https://github.com/tweag/ormolu/issues/590).

* Fixed an idempotence issue related to operators. [Issue
  522](https://github.com/tweag/ormolu/issues/522).

* Renamed the `--check-idempotency` flag to `--check-idempotence`.
  Apparently only the latter is correct.

## Fourmolu 0.0.6.0

* The project was fourked to provide four space indent.

## Ormolu 0.0.5.0

* Grouping of statements in `do`-blocks is now preserved. [Issue
  74](https://github.com/tweag/ormolu/issues/74).

* Grouping of TH splices is now preserved. [Issue
  507](https://github.com/tweag/ormolu/issues/507).

* Comments on pragmas are now preserved. [Issue
  216](https://github.com/tweag/ormolu/issues/216).

* Ormolu can now be enabled and disabled via special comments. [Issue
  435](https://github.com/tweag/ormolu/issues/435).

* Added experimental support for simple CPP. [Issue
  415](https://github.com/tweag/ormolu/issues/415).

* Added two new options `--start-line` and `--end-line` that allow us to
  select a region to format. [Issue
  516](https://github.com/tweag/ormolu/issues/516).

* Fixed rendering of module headers in the presence of preceding comments or
  Haddocks. [Issue 561](https://github.com/tweag/ormolu/issues/561).

## Ormolu 0.0.4.0

* When given several files to format, Ormolu does not stop on the first
  failure, but tries to format all the files. [Issue
  502](https://github.com/tweag/ormolu/issues/502).

* Made rendering of pattern matches involving operators consistent with
  other cases of rendering of operators. [Issue
  500](https://github.com/tweag/ormolu/issues/500).

* More compact rendering of type family injectivity constraints. [Issue
  482](https://github.com/tweag/ormolu/issues/482).

* Improved rendering of the keyword `where` in class, data, and type family
  declarations. When headers of these declarations are multi-line `where` is
  now put on its own line. [Issue
  509](https://github.com/tweag/ormolu/issues/509).

* Fixed the bug pertaining to rendering of arrow notation with multiline
  expressions. [Issue 513](https://github.com/tweag/ormolu/issues/513).

* Made rendering of data type definitions, value-level applications, and
  application of types use the same style. Moreover, existential now doesn't
  cause the data constructor be unconditionally rendered in multiline
  layout. [Issue 427](https://github.com/tweag/ormolu/issues/427).

* Records with a single data constructor are now formatted more compactly.
  [Issue 425](https://github.com/tweag/ormolu/issues/425).

* Switched to `ghc-lib-parser-8.10.1`.

* Implemented support for the new language extensions `ImportQualifiedPost`
  and `StandaloneKindSignatures`.

## Ormolu 0.0.3.1

* Fixed rendering of record updates with the record dot preprocessor syntax
  [Issue 498](https://github.com/tweag/ormolu/issues/498).

## Ormolu 0.0.3.0

* Fixed an issue related to unnecessary use of curly braces. [Issue
  473](https://github.com/tweag/ormolu/issues/473).

* Fixed the issue with formatting multi-way if when it happens to be a
  function applied to arguments [Issue
  488](https://github.com/tweag/ormolu/issues/488). This changed the way
  multi-line if is formatted in general.

* Added support for record dot pre-processor when used via the plugin.
  [Issue 486](https://github.com/tweag/ormolu/issues/486).

* Stopped hanging record constructors and improved placing
  potentially-hanging consturctions in the presence of comments. [Issue
  447](https://github.com/tweag/ormolu/issues/447).

* Fixed indentation in presence of type applications. [Issue
  493](https://github.com/tweag/ormolu/issues/493).

* Class and instance declarations now do not have a blank line after
  `where`. Grouping of methods from the original input is also preserved
  with some normalizations. [Issue
  431](https://github.com/tweag/ormolu/issues/431).

## Ormolu 0.0.2.0

* Switched to `ghc-lib-parser` instead of depending on the `ghc` package
  directly. This should allow us to use newest features of GHC while not
  necessarily depending on the newest version of the compiler. In addition
  to that Ormolu is now GHCJS-compatible.

* Now unrecognized GHC options passed with `--ghc-opt` cause Ormolu to fail
  (exit code 7).

* Fixed formatting of result type in closed type families. See [issue
  420](https://github.com/tweag/ormolu/issues/420).

* Fixed a minor inconsistency between formatting of normal and foreign type
  signatures. See [issue 408](https://github.com/tweag/ormolu/issues/408).

* Fixed a bug when comment before module header with Haddock was moved
  inside the export list. See [issue
  430](https://github.com/tweag/ormolu/issues/430).

* Empty `forall`s are now correctly preserved. See [issue
  429](https://github.com/tweag/ormolu/issues/429).

* Fixed [issue 446](https://github.com/tweag/ormolu/issues/446), which
  involved braces and operators.

* When there are comments between preceding Haddock (pipe-style) and its
  corresponding declaration they are preserved like this in the output
  instead of being shifted. To be clear, this is not a very good idea to
  have comments in that position because the Haddock will end up not being
  associated with the declarations. Issues
  [440](https://github.com/tweag/ormolu/issues/440) and
  [448](https://github.com/tweag/ormolu/issues/448).

* Implemented correct handling of shebangs. [Issue
  377](https://github.com/tweag/ormolu/issues/377).

* Implemented correct handling of stack headers. [Issue
  393](https://github.com/tweag/ormolu/issues/393).

* Sorting language pragmas cannot not change meaning of the input program
  anymore. [Issue 404](https://github.com/tweag/ormolu/issues/404).

* Fixed formatting of applications where function is a complex expression.
  [Issue 444](https://github.com/tweag/ormolu/issues/444).

## Ormolu 0.0.1.0

* Initial release.
