## Changelog

See full history at: <https://github.com/faylang/fay/commits>

#### 0.21.0.2 (2014-10-19)

* Fallback to ghc and ghc-pkg in PATH if not available from GHC.Paths

#### 0.21.0.1 (2014-10-12)

* Update to `optparse-applicative == 0.11.*`

## 0.21.0.0 (2014-10-11)

* Errors are now properly thrown from `encodeFay`. Changes the type signature to `encodeFay :: (GenericQ Value -> GenericQ Value) -> GenericQ Value`
* Update to `haskell-src-exts == 1.16.*`, This changes the type signature of `readerCompileLit` to `:: S.Sign -> S.Literal -> Compile JsExp`
* Fixes `ghc-pkg describe` stdout errors not always being printed

### 0.20.2.0 (2014-09-14)

* Config option to disable optimizations of newtypes, treating them as
  normal data types. This can be triggered by setting
  `configOptimizeNewtypes = False` or passing
  `--no-optimized-newtypes`.

#### 0.20.1.4 (2014-09-04)

* Update to `optparse-applicative == 0.10.*`

#### 0.20.1.3 (2014-08-29)

* Test suite is no longer built by default, cabal install with `-ftest` to enable.

#### 0.20.1.2 (2014-08-18)

* Updated homepage URLs, fay-lang.org was 301'd

#### 0.20.1.1 (2014-06-17)

* Don't cache the `main` thunk in the generated `main` call.

### 0.20.1.0 (2014-06-14)

* Add default case for UTCTime in Fay.Convert using the aeson instances. Note that this serializes to a json string so you won't be able to deserialize it as a separate type (such as Date) when using `Automatic` in Fay.

* Added `Fay.Config.defaultConfigWithSandbox` that reads the `HASKELL_PACKAGE_SANDBOX` environment variable. Client libraries can use this instead of manually reading from `getEnvironment`.

#### 0.20.0.4 (2014-05-23)

* Allow `optparse-applicative 0.9.*`

#### 0.20.0.3 (2014-05-09)

* Allow `mtl 2.2.*`

#### 0.20.0.2 (2014-05-08)

* Allow `haskell-names 0.4.*`

#### 0.20.0.1 (2014-05-08)

* Allow `transformers >= 0.4.1 && < 0.5`

## 0.20.0.0 (2014-04-29)

* Adds support for LambdaCase and MultiWayIf

* Modules have moved around a lot and several modules have been un-exposed. From now on you will probably only need to deal with at most `Fay` (which re-exports a lot of things), `Fay.Config`, `Fay.Types.CompileError`, `Fay.Convert`, and `Fay.Types.CompileResult`. Please let us know if you would like us to expose more things

* Config:
  * `CompileConfig` has been renamed to `Config` and is now located in `Fay.Config`.
  * `CompileConfig` has become a temporary type alias for `Config`.
  * `Fay.Compiler.Config` is deprecated, import `Fay` or `Fay.Config` instead.
  * The `data-default` instance for `Config` is deprecated, use `defaultConfig` instead.

* compiling
  * `compileFileWithState` is deprecated, use `compileFileWithResult` which returns a `Fay.Types.CompileResult` instead. As a consequence `CompileState` is also deprecated from public consumption.
  * `compileFile`, `compileFromToAndGenerateHtml` no longer return a triple with the sourcemap, use `compileFileWithResult` if you want access to this.

* Importing `Fay.Types` has been deprecated, import `Fay` instead.

* `readFromFay` has been rewritten using `syb` instead of `pretty-show` (Thanks to Michael Sloan and Chris Done)
  * This introduces the following breaking changes:
    * `readFromFay` has a `Data` constraint instead of `Show`.
    * Drops support for Rational and Integer (see below for migration steps). The reason is that neither was serialized in a way that would roundtrip for all values. Also, for similar reasons, fromRational is potentially divergent for aeson's new use of the Scientific type.
  * And adds the following features:
    * You can now write custom `Show` instances targeting GHC for types shared with Fay.
    * Better performance.
    * Allows the serialization and deserialization to be customized on a per-type basis, via encodeFay and decodeFay.
  * To migrate code using Rational or Integer, use encodeFay and pass an argument e.g. `(\f x -> maybe (f x) myIntegerToValueConversion (cast x))` and likewise to decodeFay.

Bugfixes:

* Mltiple guards on a pattern in a case expression skipped everything but the first guard. To fix this an optimization we had on pattern conditions was disabled.

Dependency bumps:

* Allow Cabal 1.20 and 1.21

Internal:

* Test cases are now using `tasty` instead of `test-framework`. To run cases in parallel use `fay-tests --num-threads=N` (see `fay-tests --help` for more info).
* Added a test group for desugaring.

#### 0.19.2.1 (2014-04-14)

* Allow `haskell-src-exts 1.15.*`

### 0.19.2 (2014-04-10)

* Fixes a bug where arrays used with empty data decls would be deserialized into a Fay list instead of kept as is.

#### 0.19.1.2 (2014-04-07)

* Fix optimizations that were not applied and add codegen test cases.

#### 0.19.1.1 (2014-03-17)

* Allow `optparse-applicative 0.8.*`

### 0.19.1 (2014-03-13)

* Added Data.Char to fay-base

Dependency bumps:
* Allow `Cabal 1.19.*`
* Allow `process 1.2.*`

#### 0.19.0.2 (2014-01-30)

Bugfixes:
* Don't export transcoding information for fay-base packages when compiling with --no-stdlib
* Better error messages when forgetting the type signature in an FFI declaration

#### 0.19.0.1 (2014-01-15)

Dependency bumps:
* Allow `aeson 0.7.*`

## 0.19 (2014-01-14)

* Made import Prelude is implicit, but note that RebindableSyntax implies NoImplicitPrelude.
* Allow FFI declarations in let and where statements: `let f :: X; f = ffi "..."` and `where f :: X; f = ffi "..."`

Bugfixes:
* Removed extra </script> tag that was generated by --html-wrapper
* FFI expressions in top level declarations now produce identical code to a normal top level FFI declaration
* Don't export Data.Ratio and Debug.Trace when using --no-stdlib

Dependency bumps:
* Allow text 1.1
* Allow attoparsec 0.11


**Note: 0.18.0.1 added source mappings returned by `Fay:compileFile` and friends meaning it should have been a major bump. Sorry about this!**

#### 0.18.1.3 (2013-12-14)

* Add parsing of Integer to Fay.Convert (note that the runtime doesn't have arbitrary precision Integers)
* Allow text 1.0.*

#### 0.18.1.2 (2013-11-26)

* Add support for indirect application of newtypes (such as `p = NewType; foo = p x` and `bar = NewType $ y`)

#### 0.18.1.1 (2013-11-22)

* Fix a bug where records with the same name as top level modules wouldn't be initialized correctly.
* Fail when using enum syntax on unsupported literal types (for instance ['a'..'z'])

### 0.18.1 (2013-11-07)

* Add support for TupleSections

#### 0.18.0.5 (2013-10-28)

Bugfixes:
* Disallow unsupported patterns in where/let declarations instead of `<<loop>>`ing on them

Minor:
* Put upper bounds on all dependencies

#### 0.18.0.4 (2013-10-25)

Bugfixes:
* Allow `//` as an operator name (added flag to `hse-cpp`)
* Don't transcode function values when using an EmptyDataDecl

#### 0.18.0.3 (2013-10-23)

Minor:
* Allow `optparse-applicative == 0.7.*`
* Fix `examples/Cont.hs`

#### 0.18.0.2 (2013-10-16)

Bug fixes:
* Regression: Work around a bug in optparse-applicative 0.6 that prevents `--strict` from being used.

#### 0.18.0.1 (2013-10-16)

* Source maps for top level definitions, use `--sourcemap`

Bug fixes:
* Regression: Equality checks for (G)ADTs (`deriving Eq`)
* Fix `--strict` for top level ADT values (such as `module M where g = R`)
* Regression: Serialization in the presence of compression/renaming
* Pass NoImplicitPrelude (and other enabled extensions) to haskell-names to resolve ambiguities when Prelude isn't imported.

Minor:
* Bump optparse-applicative to 0.6.*
* Bump haskell-names to 0.3.1 to allow compilation with Cabal 1.14
* Ignore more declarations (useful when code sharing with GHC)

## 0.18.0.0 (2013-09-24)

New features:
* Support for qualified imports. Note: You still can't have multiple constructors with the same name in the FFI since the `instance` field in the serialization is still unqualified.
* `Automatic` transcoding now works for functions. See [Calling Fay From JavaScript](https://github.com/faylang/fay/wiki/Calling-Fay-from-JavaScript)
* `--strict modulename[, ..]` generates strict and transcoding wrappers for a module's exports. See [Calling Fay From JavaScript](https://github.com/faylang/fay/wiki/Calling-Fay-from-JavaScript)
* `--typecheck-only` just runs the GHC type checker with the appropriate Fay flags.
* `--runtime-path FILEPATH` allows you to supply a custom runtime. Probably only useful for debugging.

Bug fixes:
* Don't crash when trying to get the fayToJsFun of an object without constructor.name
* Fixed bug that accidentally flattened list arguments in `jsToFay`
* Fix construction with RecordWildCards not taking already listed fields into account

Breaking Changes:
* Fay.Compiler.Debug has been removed (for now)
* The interactive compilation mode has been removed (for now)

Internal changes:
* Migrated to haskell-src-ext's annotated AST.
* Name resolution is now done using haskell-names, Fay's name resolution code is now pure and a lot simpler.

## 0.17.0.0 (2013-08-27)

* With the `RebindableSyntax` and `OverloadedStrings` extensions Fay will treat Haskell string literals as JavaScript Strings. Add this in all modules and import Fay.Text (from the `fay-text` package). This is *not* a breaking change, without these extensions in a module `String` will be used, as before. All modules can still interoperate normally even if only some of them use this feature. Note that you may have to define `fromInteger` when using this with Num literals.

* The type signature of `Fay.FFI.ffi` (in fay) and `FFI.ffi` (in fay-base) has been generalized to `IsString s => s -> a` to support `RebindableSyntax`.

* Much faster compile time (of the compiler itself) by having the executables depend on the library.

Bugfixes:
* The empty list and unit is now serialized to `null` when using Automatic (it used to throw an error).

Minor:
* Restrict upper bound on `language-ecmascript` to `< 1.0`

#### 0.16.0.3 (2013-08-23)

* Support for tuple constructors (`(,,) 1,2,3`)

Minor:
* Bump `pretty-show` to `>= 1.6`
* Remove the `-fdevel` flag (when compiling fay itself)

#### 0.16.0.2 (2013-08-21)

Minor:
* Bump `haskell-src-exts` to `>= 1.14`

#### 0.16.0.1 (2013-08-08)

Bugfixes:
 * Allow combining multiline strings with CPP

## 0.16.0.0 (2013-08-05)
 * New module generation, modules generate code separately in the format `My.Module.foo` instead of `My$Module$foo`
 * Transcoding information is also produced separately for each module
 * Removed `--naked`, `--dispatcher`, and `--no-dispatcher`. They are probably not needed anymore
 * Removed `Fay$$fayToJsUserDefined` and `Fay$$jsToFayUserDefined`, instead call `Fay$$fayToJs` and `Fay$$jsToFay` respectively
 * Escape semi reserved words from `Object` when printing (`constructor` -> `$constructor`). This only matters if you call Fay from JS
 * `Automatic` now handles lists and tuples (#251)
 * `Language.Fay.FFI` renamed to `Fay.FFI` (as before, Fay code can import `FFI` from `fay-base`)

Minor:
 * Print location of parse errors
 * Compile with -XNoImplicitPrelude
 * Support for testing nested modules (module A, module A.B)
 * Bump `language-ecmascript to >= 0.15` (new API)
 * Rename/remove some CompileErrors
 * All tests are now included in dist

Bug fixes:
 * Force cars in string serialization (#306)

## 0.15.0.0 (2013-06-08)
 * Expression level FFI calls, `ffi "alert('hello!')" :: Fay ()`
 * Support let pattern matches
 * Smaller output for serialization code
 * --base-path flag to use a custom base (mainly for fay-prim)
 * Allow ExistentialQuantification, FlexibleContexts, FlexibleInstances, KindSignatures
 * Verify that GADTs using non-record syntax works
 * JS->Fay function serialization
 * Serialization support for `()`, tuples and `Char`
 * Add more reserved words for Google Closure

Bugfixes:
 * Fix a bug when an imported module contains types
 * Fix a bug with EModuleContents exports
 * Fix where clause inside pattern guards in function definitions
 * Fix type variables in serialization for multiple constructors
 * Fix EThingAll exports for types with constructors with a different name
 * Don't export types in EThingAll and EThingWith


### 0.14.5.0 (2013-04-24)
* Support for newtypes (with no runtime cost!)
* --base-path flag to specify custom locations for fay-base
* Fix a bug where imports shadowing local bindings would prevent the local binding from being exported


### 0.14.4.0 (2013-04-21)
* Fix record updates on IE <= 8
* Import tweaks, will make compilation a lot faster (4x reported) when there are a lot of imports
* Parse hs sources with base fixities