# Changelog for [`clash-prelude` package](http://hackage.haskell.org/package/clash-prelude)
## 0.11 *January 16th 2017*
* New features:
* `CLaSH.XException`: a module defining an exception representing uninitialised values. Additionally adds the `ShowX` class which has methods that print values as "X" where they would normally raise an `XException` exception.
* Add `BNat` (and supporting functions) to `CLaSH.Promoted.Nat`: base-2 encoded natural numbers.
* Add `divSNat` and `logBaseSNat` to `CLaSH.Promoted.Nat`: division and logarithm for singleton natural numbers.
* Add `predUNat` and `subUNat` to `CLaSH.Promoted.Nat`: predecessor and subtraction for unary-encoded natural numbers.
* Add `dtfold` to `CLaSH.Sized.Vector`: a dependently-typed tree-fold over `Vec`.
* Add the perfect-depth binary trees module `CLaSH.Sized.RTree`
* Synthesisable definitions of `countLeadingZeros` and `countTrailingZeros` for: `BitVector`, `Signed`, `Unsigned`, and `Fixed`
* Add the `(:::)` type alias in `CLaSH.NamedTypes` which allows you to annotate types with documentation
* Changes:
* `asyncRam`, `blockRam`, `blockRamFile` have a `Maybe (addr,a)` as write input instead of three separate `Bool`, `addr`, and `a` inputs.
* `asyncFIFOSynchronizer` has a `Maybe a` as write-request instead of a separate `Bool` and `a` input
* `bundle'` and `unbundle'` are removed; `bundle` now has type `Unbundled' clk a -> Signal' clk a`, `unbundle` now has type `Signal' clk a -> Unbundled' clk a`
* `subSNat` now has the type `SNat (a+b) -> SNat b -> SNat a` (where it used to be `SNat a -> SNat b -> SNat (a-b)`)
* Renamed `multUNat` to `mulUNat` to be in sync with `mulSNat` and `mulBNat`.
* The function argument of `vfold` in `CLaSH.Sized.Vector` is now `(forall l . SNat l -> a -> Vec l b -> Vec (l + 1) b)` (where it used to be `(forall l . a -> Vec l b -> Vec (l + 1) b)`)
* `Cons` constructor of `Vec` is no longer visible; `(:>)` and `(:<)` are now listed as constructors of `Vec`
* Simulation speed improvements for numeric types
## 0.10.12
* Fixes bugs:
* `Vec`s `unbundle` is too strict, i.e. `register (undefined :: Vec 2 Int)` /= `bundle . unbundle . register (undefined :: Vec 2 Int)`
## 0.10.11 *August 3rd 2016*
* New features:
* Add strict version of: `sample`, `sampleN`, `fromList`, and `simulate`
* Make `Signal`s `<*>` slightly stricter:
* Feedback loops still work with this new implementation
* No more space-leaks when used in combination with the strict version of `sample`, `sampleN`, and `simulate`
* Add `NFData` instances for the numeric types
* Speed up arithmetic operations of `Signed`, `Unsigned` and `BitVector`
* Fixes bugs:
* CLaSH compiler sees internals of numeric types in their `Lift` functions
## 0.10.10 *July 15th 2016*
* Fixes bugs:
* `shrink` functions for numeric types throw exceptions [#153](https://github.com/clash-lang/clash-compiler/issues/153)
* CLaSH compiler sees internals of numeric types in their Show functions
## 0.10.9 *June 9th 2016*
* Fixes bugs:
* `Eq` instance of `Vec` sometimes not synthesisable
## 0.10.8 *June 7th 2016*
* New features:
* Instances of `Data` for numeric types.
* Instances of `Read` for {Index, Signed, Unsigned, Fixed}
* Instances of `BitPack` for 3-8 tuples
## 0.10.7 *April 7th 2016*
* Support doctest-0.11.0
## 0.10.6 *February 10th 2016*
* Fixes bugs:
* `CLaSH.Prelude.DataFlow.parNDF` is not lazy enough
## 0.10.5 *January 13th 2016*
* New features:
* Add `readNew` to `CLaSH.Prelude.BlockRam`: create a read-after-write blockRAM from a read-before-write blockRAM.
* `popCount` functions for `BitVector`, `Signed`, and `Unsigned` are now synthesisable.
* Add `parNDF` to `CLaSH.Prelude.DataFlow`: compose _N_ dataflow circuits in parallel.
* Add and instance `Vec n a` for `LockStep` in `CLaSH.Prelude.DataFlow`: have _N_ dataflow circuits operate in lock-step.
## 0.10.4 *December 11th 2015*
* New features:
* Add `pureDF` to `CLaSH.Prelude.DataFlow`: lift combinational circuits to `DataFlow` circuits.
* Add `fifoDF` to `CLaSH.Prelude.DataFlow`: a simple FIFO buffer adhering to the `DataFlow` protocol.
* `loopDF` no longer uses the `lockStep` and `stepLock` automatically, and now includes a FIFO buffer on the feedback path.
* Add `loopDF_nobuf` to `CLaSH.Prelude.DataFlow`: a version of `loopDF` with no FIFO buffer on the feedback path.
* Add `boolToBV` to `CLaSH.CLass.BitPack`: convert `Bool`eans to `n`-bit `BitVector`s.
* `ClockSource` in `CLaSH.Annotations.TopEntity` can now have multiple clock inputs [#33](https://github.com/clash-lang/clash-prelude/issues/33)
* Bug fixes:
* `asyncRomFile` reads file multiple times.
## 0.10.3 *October 24th 2015*
* Disable CPR analysis (See https://github.com/clash-lang/clash-compiler/commit/721fcfa9198925661cd836668705f817bddaae3c):
* GHC < 7.11: In all modules using `-fcpr-off`
* GHC >= 7.11: In `CLaSH.Signal.Internal` and `CLaSH.Prelude.RAM` using `-fno-cpr-anal`
## 0.10.2 *October 21st 2015*
* New features:
* `ExtendingNum`, `BitPack`, and `Resize` instance for `Index`
* Add `bv2i`: convert `BitVector n` to `Index (2^n)`
* Export type-level operations from [ghc-typelits-extra](http://hackage.haskell.org/package/ghc-typelits-extra)
## 0.10.1 *October 16th 2015*
* New features:
* The `f` in `dfold p f`, now has an `SNat l` instead of a `Proxy l` as its first argument.
* Add `bv2v` and `v2bv` functions that convert between `Vec n Bit` and `BitVector n`.
* Add `smap`: apply a function to every element of a vector and the element's position (as an 'SNat' value) in the vector.
## 0.10 *October 3rd 2015*
* New features:
* The Vec constructor `:>` is now an explicitly bidirectional pattern synonym (the actual constructor has been renamed to Cons).
As a result, pattern matching on `:>` is now synthesisable by the CLaSH compiler.
* The function `<:` is replaced by the the explicitly bidirectional pattern synonym `:<`.
This allows you to pattern match on: "all but the last element of a vector" and "the last element" of the vector.
Because it is a bidirectional pattern, `:<` can also be used as an expression that appends an element to the tail of a vector.
* Add a `transpose` function in `CLaSH.Sized.Vector`.
* Add `stencil1d` and `stensil2d` stencil computation functions in `CLaSH.Sized.Vector`.
* Add `permute`, `backpermute`, `scatter`, and `gather` permutation functions in `CLaSH.Sized.Vector`.
* Add specialised permutation functions `interleave`, `rotateLeft`, and `rotateRight` in `CLaSH.Sized.Vector`.
* `sscanl` and `sscanr` in `CLaSH.Sized.Vector` are renamed to `postscanl` and postscanr` to be more in line with existing Haskell packages such as `vector` and `accelerate`.
* The `Foldable` and `Traversable` instances of `Vec` now only works for non-empty vectors.
* Where possible, members of the `Foldable` instance of `Vec` are described in terms of `fold`, which builds a tree (of depth `log(n)`) of computations, instead of `foldr` which had depth `n` computations.
This reduces the critical path length in your circuits when using these functions.
* `maxIndex` and `length` in `CLaSH.Sized.Vector` return an `Int` instead of an `Integer`.
* Add functions that involve an index into a vector to the `CLaSH.Sized.Vector` module: `indices`, `indicesI`, `imap`, `izipWith`, `ifoldr`, `ifoldl`, `findIndex`, `elemIndex`.
* `CLaSH.Sized.Vector`'s `fold`, `dfold`, `vfold`, and `toList` are now synthesisable by the CLaSH compiler.
## 0.9.3 *September 21st 2015*
* Fixes bugs:
* Cannot build against singletons-0.2
* Numerous documentation fixes
## 0.9.2 *August 2nd 2015*
* Disable strictness analysis in `CLaSH.Signal.Internal`, this allows turning on strictness analysis in the GHC front-end of the CLaSH compiler.
## 0.9.1 *June 26th 2015*
* Updated documentation on data-file support on Altera/Quartus
## 0.9 *June 25th 2015*
* New features:
* Add operations on singleton natural numbers: `addSNat`, `subSNat`, `mulSNat`, and `powSNat`.
* Add asynchronous RAM functions in `CLaSH.Prelude.RAM`, which have an asynchronous/combinational read port.
* Add ROM functions in modules `CLaSH.Prelude.ROM` and `CLaSH.Prelude.ROM.File`, where the latter module contains functions that instantiate a ROM from the content specified in an external data-file.
* Add BlockRam functions, in the `CLaSH.Prelude.BlockRam.File` module, whose content can be initialised with the content specified in an external data-file.
* `assert` now takes an extra `String` argument so you can distinguish one `assert` from the others.
Additionally, `assert'` is added which takes an additional `SClock` argument.
This is needed, because `assert` now reports the clock cycle, and clock domain, when an assertion fails.
* `defClkAltera` and `defClkXilinx` are replaced by, `altpll` and `alteraPll` for Altera clock sources, and `clockWizard` for Xilinx clock sources.
These names correspond to the names of the generator utilities in Quartus and ISE/Vivado.
* Add [Safe](https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/safe-haskell.html) versions of the prelude modules: `CLaSH.Prelude.Safe` and `CLaSH.Prelude.Explicit.Safe`
* Add synchronizers in the `CLaSH.Prelude.Synchronizer` module
## 0.8 *June 3rd 2015*
* New features:
* Make the (Bit)Vector argument the _last_ argument for the following functions: `slice`, `setSlice`, `replaceBit`, `replace`. The signatures for the above functions are now:
```
slice :: BitPack a => SNat m -> SNat n -> a -> BitVector (m + 1 - n)
setSlice :: BitPack a => SNat m -> SNat n -> BitVector (m + 1 - n) -> a -> a
replaceBit :: Integral i => i -> Bit -> a -> a
replace :: Integral i => i -> a -> Vec n a -> Vec n a
```
This allows for easier chaining, e.g.:
```
replaceBit 0 1 $
repleceBit 4 0 $
replaceBit 6 1 bv
```
* Until version 0.7.5, given `x :: Vec 8 Bit` and `y :: BitVector 8`, it used to be `last x == msb y`.
This is quite confusing when printing converted values.
Until version 0.7.5 we would get:
```
> 0x0F :: BitVector 8
0000_1111
> unpack 0x0F :: Vec 8 Bit
<1,1,1,1,0,0,0,0>
```
As of version 0.8, we have `head x == msb y`:
```
> 0x0F :: BitVector 8
0000_1111
> unpack 0x0F :: Vec 8 Bit
<0,0,0,0,1,1,1,1>
```
So converting for `Vec`tors of `Bit`s to `BitVector`s is no longer _index_-preserving, but it is _order_-preserving.
* Add [QuickCheck](http://hackage.haskell.org/package/QuickCheck) `Arbitary` and `CoArbitary` instances for all data types
* Add [lens](http://hackage.haskell.org/package/lens) `Ixed` instances for `BitVector`, `Signed`, `Unsigned`, and `Vec`
## 0.7.5 **May 7th 2015**
* New features:
* Moore machine combinators
## 0.7.4 **May 5th 2015*
* New features:
* Add `TopEntity` annotations
## 0.7.3 *April 22nd 2015*
* New features:
* Add the vector functions: `zip3`, `unzip3`, and `zipWith3`
* Use version 0.2 of the [`ghc-typelits-natnormalise` package](http://hackage.haskell.org/package/ghc-typelits-natnormalise)
## 0.7.2 *April 20th 2015*
* New features:
* Support for GHC 7.10 => only works with GHC 7.10 and higher
* Use http://hackage.haskell.org/package/ghc-typelits-natnormalise typechecker plugin for better type-level natural number handling
## 0.7.1 *March 25th 2015*
* Fixes bugs:
* Fix laziness bug in Vector.(!!) and Vector.replace
## 0.7 *March 13th 2015*
* New features:
* Switch types of `bundle` and `bundle'`, and `unbundle` and `unbundle'`.
* Rename all explicitly clocked versions of Signal functions, to the primed
name of the implicitly clocked Signal functions. E.g. `cregister` is now
called `register'` (where the implicitly clocked function is callled `register`)
* Add new instances for `DSignal`
* Add experimental `antiDelay` function for `DSignal`
* Generalize lifted functions over Signals (e.g. (.==.))
* Fixes bugs:
* Faster versions of Vector.(!!) and Vector.replace
## 0.6.0.1 *November 17th 2014*
* Fixes bugs:
* Add missing 'CLaSH.Sized.BitVector' module to .cabal file.
## 0.6 *November 17th 2014*
* New features:
* Add `Fractional` instance for `Fixed` [#9](https://github.com/christiaanb/clash-prelude/issues/9)
* Make indexing/subscript of `Vec` ascending [#4](https://github.com/christiaanb/clash-prelude/issues/4)
* Add separate `BitVector` type, which has a descending index.
* Add bit indexing operators, including the index/subscript operator `(!)`.
* Add bit reduction operators: `reduceOr`, `reduceAnd`, `reduceOr`.
* Rename `BitVector` class to `BitPack` with `pack` and `unpack` class methods.
* Rename `Pack` class to `Bundle` with `bundle` and `unbundle` class methods.
* Strip all `Vec` functions from their `v` prefix, i.e. `vmap` -> `map`.
* Rename `Vec` indexing operator from `(!)` to `(!!)`.
* Combine `Add` and `Mult` class into `ExtendingNum` class.
* Add extend and truncate methods to the `Resize` class.
* Add `SaturatingNum` class with saturating numeric operators.
* Add multitude of lifted `Signal` operators, i.e. `(.==.) :: Eq a => Signal a -> Signal a -> Signal Bool`
* Add `CLaSH.Signal.Delayed` with functions and data types for delay-annotated signals to support safe synchronisation.
* Add `CLASH.Prelude.DataFlow` with functions and data types to create self-synchronising circuits based on data-flow principles.
* Fixes bugs:
* Remove deprecated 'Arrow' instance for and related functions for `Comp` [#5](https://github.com/christiaanb/clash-prelude/issues/5)
## 0.5.1 *June 5th 2014*
* New features:
* Add `Default` instance for `Vec` [#2](https://github.com/christiaanb/clash-prelude/issues/2)
* Instantiation for `blockRam` [#3](https://github.com/christiaanb/clash-prelude/issues/2)
* Fixes bugs:
* Fixed error on documentation of fLit in Fixed.hs [#6](https://github.com/christiaanb/clash-prelude/issues/6)
* Non-translatable `Enum` function interfere with `sassert` compilation [#7](https://github.com/christiaanb/clash-prelude/issues/7)
* Substituted the word 'list' into 'vector' in some places in the documentation. [#8](https://github.com/christiaanb/clash-prelude/issues/8)
* mark vselectI INLINEABLE [#10](https://github.com/christiaanb/clash-prelude/issues/10)
## 0.5 *April 3rd 2014*
* Add explicitly clocked synchronous signals for multi-clock circuits
## 0.4.1 *March 27th 2014*
* Add saturation to fixed-point operators
* Finalize most documentation
## 0.4 *March 20th 2014*
* Add fixed-point integers
* Extend documentation
* 'bit' and 'testBit' functions give run-time errors on out-of-bound positions
## 0.3 *March 14th 2014*
* Add Documentation
* Easy SNat literals for 0..1024, e.g. d4 = snat :: SNat 4
* Fix blockRamPow2
## 0.2 *March 5th 2014*
* Initial release