This CHANGELOG describes the history of already-released versions. Please see [CHANGELOG_NEXT](./CHANGELOG_NEXT.md) for changes merged into the main branch but not yet released. # Changelog ## v0.7.0 ### Language changes * New magic constants `__LOC__`, `__FILE__`, `__LINE__`, `__COL__` substituted at parsing time with a string corresponding to the location, filename, line or column number associated to the magic constant's position. * The termination checker is now a faithful implementation of the 2001 paper on size-change termination by Lee, Jones and Ben-Amram. * New function option `%unsafe` to mark definitions that are escape hatches similar to the builtins `believe_me`, `assert_total`, etc. * Elaborator scripts were made be able to record warnings. * Rudimentary support for defining lazy functions (addressing issue [#1066](https://github.com/idris-lang/idris2/issues/1066)). * `%hide` directives can now hide conflicting fixities from other modules. * Fixity declarations can now be kept private with export modifiers. * Forward-declarations whose visibility differ from their actual definition now emit a warning, unless the definition has no specified visibility (addressing Issue [#1236](https://github.com/idris-lang/Idris2/issues/1236)). * New `fromTTImp`, `fromName`, and `fromDecls` names for custom `TTImp`, `Name`, and `Decls` literals. * Call to `%macro`-functions do not require the `ElabReflection` extension. * Default implicits are supported for named implementations. * Elaborator scripts were made to be able to access project files, allowing the support for type providers and similar stuff. * Elaborator scripts were made to be able to inspect which definitions are referred to by another definitions, and in which function currently elaborator is. These features together give an ability to inspect whether particular expressions are recursive (including mutual recursion). ### REPL/CLI changes * Adds documentation for unquotes `~( )`. * Adds documentation for laziness and codata primitives: `Lazy`, `Inf`, `Delay`, and `Force`. * Adds `--no-cse` command-line option to disable common subexpression elimination for code generation debugging. ### Backend changes #### RefC * Adds support for `CFLAGS`, `CPPFLAGS`, `LDFLAGS` and `LDLIBS` to facilitate building on systems with non-standard installation locations of libraries (e.g. GMP). Versions of the flags with the `IDRIS2_` prefix can also be used and take precedence. #### Chez * Non-recursive top-level constants are compiled to eagerly evaluated constants in Chez Scheme. #### Racket * FFI declarations can now specify which `require` to perform, i.e. which library to load before executing the FFI. The syntax is `scheme,racket:my-function,my-library`. #### Node.js/Browser * Generated JavaScript files now include a shebang when using the Node.js backend * NodeJS now supports `popen`/`pclose` for the `Read` mode. * `getChar` is now supported on Node.js and `putChar` is supported on both JavaScript backends. * Integer-indexed arrays are now supported. ### Compiler changes * If `IAlternative` expression with `FirstSuccess` rule fails to typecheck, compiler now prints all tried alternatives, not only the last one. * The elaboration of records has been changed so that the unbound implicits in the parameters' types become additional parameters e.g. ```idris2 record HasLength (xs : List a) (n : Nat) where constructor MkHasLength 0 prf : length xs === n ``` is now correctly elaborated to ```idris2 record HasLength {0 a : Type} (xs : List a) (n : Nat) where constructor MkHasLength 0 prf : length xs === n ``` instead of failing with a strange error about (a) vs (a .rec). * Elaboration of datatypes now respects the totality annotations: defining a `covering` or `partial` datatype in a `%default total` file will not lead to a positivity error anymore. * Fixed a bug in the positivity checker that meant `Lazy` could be used to hide negative occurrences. * Made sure that the positivity checker now respects `assert_total` annotations. * We now raise a warning for conflicting fixity declarations. They are dangerous as Idris will pick an arbitrary one and so the meaning of an expression can depend e.g. on the order in which modules are imported. * Additionally some conflicting fixity declarations in the Idris 2 compiler and libraries have been removed. * Constructors mentioned on the left hand side of functions/case alternatives are now included in the `Refers to (runtime)` section of functions debug info. * The Lifted IR Representation now has a `HasNamespaces` implementation in `Compiler.Separate` so Compilation Units at that stage can be generated. * Added the `compile.casetree.missing` log topic, along with its use in `TTImp.ProcessDef.genRunTime`. This allows us to track when incomplete `case` blocks get the runtime error added. * Constant folding of trivial let statements and `believe_me`. * Fixed a bug that caused holes to appear unexpectedly during quotation of dependent pairs. * Fixed a bug that caused `f` to sometimes be replaced by `fx` after matching `fx = f x`. * Fixed a bug in the totality checker that missed indirect references to partial data. * Refactor the idris2protocols package to depend on fewer Idris2 modules. We can now export the package independently. To avoid confusing tooling about which `.ipkg` to use, the package file is under the newly added `ipkg` sub-directory. * Added `Libraries.Data.WithDefault` to facilitate consistent use of a default-if-unspecified value, currently for `private` visibility. ### Library changes #### Prelude * Improved performance of functions `isNL`, `isSpace`, and `isHexDigit`. * Implements `Foldable` and `Traversable` for pairs, right-biased as `Functor`. * Added a constructor (`MkInterpolation`) to `Interpolation`. * Added an `Interpolation` implementation for `Void`. * Added `Compose` instances for `Bifunctor`, `Bifoldable` and `Bitraversable`. #### Base * Deprecates `setByte` and `getByte` from `Data.Buffer` for removal in a future release. Use `setBits8` and `getBits8` instead (with `cast` if you need to convert a `Bits8` to an `Int`), as their values are limited, as opposed to the assumption in `setByte` that the value is between 0 and 255. * Adds RefC support for 16- and 32-bit access in `Data.Buffer`. * Add `Show` instance to `Data.Vect.Quantifiers.All` and add a few helpers for listy computations on the `All` type. * Add an alias for `HVect` to `All id` in `Data.Vect.Quantifiers.All`. This is the approach to getting a heterogeneous `Vect` of elements that is general preferred by the community vs. a standalone type as seen in `contrib`. * Add `Data.List.HasLength` from the compiler codebase slash contrib library but adopt the type signature from the compiler codebase and some of the naming from the contrib library. The type ended up being `HasLength n xs` rather than `HasLength xs n`. * Moved `Data.SortedMap` and `Data.SortedSet` from contrib to base. * Added missing buffer primitives (chezscheme only): `setInt8`, `getInt8`, `getInt16`, `setInt64`, `getInt64` * Added new buffer (set/get) functions for built-in types `Bool`, `Nat`, `Integer`. * Tightened the types of: `setInt16` (now takes an `Int16` instead of an `Int`), `setInt32` (now takes an `Int32` instead of an `Int`), `getInt32` (now returns an `Int32` instead of an `Int`) * Adds left- and right-rotation for `FiniteBits`. * Adds `Vect.permute` for applying permutations to `Vect`s. * Adds `Vect.kSplits` and `Vect.nSplits` for splitting a `Vect` whose length is a known multiple of two `Nat`s (k * n) into k vectors of length n (and vice-versa). * Adds `Vect.allFins` for generating all the `Fin` elements as a `Vect` with matching length to the number of elements. * Add `withRawMode`, `enableRawMode`, `resetRawMode` for character at a time input on stdin. * Adds extraction functions to `Data.Singleton`. * `TTImp` reflection functions are now `public export`, enabling use at the type-level. * Implemented `Eq`, `Ord`, `Semigroup`, and `Monoid` for `Data.List.Quantifiers.All.All` and `Data.Vect.Quantifiers.All.All`. * Generalized `imapProperty` in `Data.List.Quantifiers.All.All` and `Data.Vect.Quantifiers.All.All`. * Add `zipPropertyWith`, `traverseProperty`, `traversePropertyRelevant`, `mapPropertyRelevant`, `(++)`, `tabulate` and `remember` to `Data.Vect.Quantifiers.All.All`. * Add `anyToFin` to `Data.Vect.Quantifiers.Any`, converting the `Any` witness to the index into the corresponding element. * Implemented `Ord` for `Language.Reflection.TT.Name`, `Language.Reflection.TT.Namespace` and `Language.Reflection.TT.UserName`. * Adds `leftmost` and `rightmost` to `Control.Order`, a generalisation of `min` and `max`. * Adds `even` and `odd` to `Data.Integral`. * `Eq` and `Ord` implementations for `Fin n` now run in constant time. * Adds `getTermCols` and `getTermLines` to the base library. They return the size of the terminal if either stdin or stdout is a tty. * The `Data.List1` functions `foldr1` and `foldr1By` are now `public export`. * Added `uncons' : List a -> Maybe (a, List a)` to `base`. * Adds `infixOfBy` and `isInfixOfBy` into `Data.List`. * Adds `WithDefault` into `Language.Reflection.TTImp`, mirroring compiler addition. * Adds updating functions to `SortedMap` and `SortedDMap`. * Adds `grouped` function to `Data.List` for splitting a list into equal-sized slices. * Implements `Ord` for `Count` from `Language.Reflection`. * Implements `MonadState` for `Data.Ref` with a named implementation requiring a particular reference. * Adds implementations of `Zippable` to `Either`, `Pair`, `Maybe`, `SortedMap`. * Adds a `Compose` and `FromApplicative` named implementations for `Zippable`. * Adds `Semigroup`, `Applicative`, `Traversable` and `Zippable` for `Data.These`. * Adds bindings for IEEE floating point constants NaN and (+/-) Inf, as well as machine epsilon and unit roundoff. Speeds vary depending on backend. * A more generalised way of applicative mapping of `TTImp` expression was added, called `mapATTImp`; the original `mapMTTimp` was implemented through the new one. * Adds `Data.Vect.foldrImplGoLemma`. * `Ref` interface from `Data.Ref` inherits `Monad` and was extended by a function for value modification implemented through reading and writing by default. #### System * Changes `getNProcessors` to return the number of online processors rather than the number of configured processors. * `System`'s `die` now prints the error message on stderr rather than stdout * Adds `popen2` to run a subprocess with bi-directional pipes. * A function `popen2Wait` was added to wait for the process started with `popen2` function and clean up all system resources (to not to leave zombie processes in particular). * Function `getStringAndFree` from `System.File.ReadWrite` was given an extra argument of type `File` to return an empty string if no error happened. ### Contrib * Adds `Data.List.Sufficient`, a small library defining a structurally inductive view of lists. * Remove `Data.List.HasLength` from `contrib` library but add it to the `base` library with the type signature from the compiler codebase and some of the naming from the `contrib` library. The type ended up being `HasLength n xs` rather than `HasLength xs n`. * Adds an implementation for `Functor Text.Lexer.Tokenizer.Tokenizer`. * Adds `modFin` and `strengthenMod` to `Data.Fin.Extra`. These functions reason about the modulo operator's upper bound, which can be useful when working with indices (for example). * Existing specialised variants of functions from the `Traversable` for `LazyList` were made to be indeed lazy by the effect, but their requirements were strengthened from `Applicative` to `Monad`. * Implements `Sized` for `Data.Seq.Sized` and `Data.Seq.Unsized`. #### Papers * In `Control.DivideAndConquer`: a port of the paper "A Type-Based Approach to Divide-And-Conquer Recursion in Coq" by Pedro Abreu, Benjamin Delaware, Alex Hubers, Christa Jenkins, J. Garret Morris, and Aaron Stump. [https://doi.org/10.1145/3571196](https://doi.org/10.1145/3571196) * Ports the first half of "Deferring the Details and Deriving Programs" by Liam O'Connor as `Data.ProofDelay`. [https://doi.org/10.1145/3331554.3342605](https://doi.org/10.1145/3331554.3342605) [http://liamoc.net/images/deferring.pdf](http://liamoc.net/images/deferring.pdf) ### Other Changes * The `data` subfolder of an installed or local dependency package is now automatically recognized as a "data" directory by Idris 2. See the [documentation on Packages](https://idris2.readthedocs.io/en/latest/reference/packages.html) for details. * The compiler no longer installs its own C support library into `${PREFIX}/lib`. This folder's contents were always duplicates of files installed into `${PREFIX}/idris2-${IDRIS2_VERSION}/lib`. If you need to adjust any tooling or scripts, point them to the latter location which still contains these installed library files. * Renamed `support-clean` Makefile target to `clean-support`. This is in line with most of the `install-<something>` and `clean-<something>` naming. * Fixes an error in the `Makefile` where setting `IDRIS2_PREFIX` caused bootstrapping to fail. * Updates the docs for `envvars` to match the changes introduced in #2649. * Both `make install` and `idris2 --install...` now respect `DESTDIR` which can be set to install into a staging directory for distro packaging. * Updates the docs for `envvars` to categorise when environment variables are used (runtime, build-time, or both). * Fixed build failure occuring when `make -j` is in effect. * Add `clean_names` function to `testutils.sh` to normalise machine names ## v0.6.0 ### REPL changes * New experimental Scheme based evaluator (only available if compiled via Chez scheme or Racket). To access this at the REPL, set the evaluator mode to the scheme based evaluator with `:set eval scheme`. * New option `evaltiming` to time how long an evaluation takes at the REPL, set with `:set evaltiming`. * Renames `:lp/loadpackage` to `:package`. * Adds `:import`, with the same functionality as `:module`. * Adds the ability to request detailed help via `:help <replCmd>`, e.g. `:help :help` or `:help :let`. This also works with the `:?` and `:h` aliases. ### Language changes * There were two versions of record syntax used when updating records: ```idris record { field = value } r ``` and ```idris { field := value } r ``` The former is now deprecated in favour of the latter syntax. The compiler will issue a warning when using the `record` keyword. * Interpolated strings now make use of `concat` which is compiled into `fastConcat`. The interpolated slices now make use of the `Interpolation` interface available in the prelude. It has only one method `interpolate` which is called for every expression that appears within an interpolation slice. ```idris "hello \{world}" ``` is desugared into ```idris concat [interpolate "hello ", interpolate world] ``` This allows you to write expressions within slices without having to call `show` but for this you need to implement the `Interpolation` interface for each type that you intend to use within an interpolation slice. The reason for not reusing `Show` is that `Interpolation` and `Show` have conflicting semantics, typically this is the case for `String` which adds double quotes around the string. * Adds a `failing` block that requires its body to fail with a compile error. Optionally this block may contain a string which is checked to be contained in the error message. * Bodies of `mutual`, `failing`, `using` and `parameters` blocks are required to be indented comparing to the position of the keyword. * `%nomangle` has been deprecated in favour of `%export`. * Records now support DataOpts, i.e. we can write things like ```idris record Wrap (phantom : Type) (a : Type) where [search a] -- this was previously not supported constructor MkWrap unWrap : a ``` * Adds ability to forward-declare interface implementations, e.g.: ```idris implementation IsOdd Nat -- forward declare for use in `IsEven` implementation IsEven Nat where isEven 0 = True isEven (S k) = not $ isOdd k implementation IsOdd Nat where isOdd 0 = False isOdd (S k) = not $ isEven k ``` * Adds ability to forward-declare records, e.g.: ```idris record B record A where b : B record B where a : A ``` ### Compiler changes * Removes deprecated support for `void` primitive. Now `void` is supported via `prim__void`. * Adds `%deprecate` pragma that can be used to warn when deprecated functions are used. * Package files now support a `langversion` field that can be used to specify what versions of Idris a package supports. As with dependency versions, `>`, `<`, `>=`, and `<=` can all be used. + For example, `langversion >= 0.5.1`. * Alternatives for primitive types of the `Core.TT.Constant` are moved out to a separate data type `PrimTypes`. Signatures of functions that were working with `Constant` are changed to use `PrimTypes` when appropriate. * Codegens now take an additional `Ref Syn SyntaxInfo` argument. This empowers compiler writers to pretty print core terms e.g. to add comments with the original type annotations in the generated code. * `Refc.showcCleanStringChar` forgot some symbols which have now been added, ensuring the string is properly cleaned. * Constant-folds all casts and integral expressions (with the exception of type `Int`), leading to improved performance. * Increases accuracy of error reporting for keywords. * Adds the `eval.stuck.outofscope` log topic in order to be able to spot when we get stuck due to a function being out of scope. * Improves the error reporting for syntactically incorrect records. * `IPragma` now carries an `FC` with it for better error reporting. * Adds the number of enum constructors to enum types during codegen, to allow for trivial conversion to, e.g., `Bits32`. * Adds constant-folding for `Nat` literals. * Fixes `CyclicMeta` in `TTImp.ProcessDef` being considered a recoverable error. ### IDE protocol changes * The IDE protocol and its serialisation to S-Expressions are factored into a separate module hierarchy Protocol.{Hex, SExp, IDE}. * File context ranges sent in the IDE protocol follow the same convention as Bounds values in the parser: + all offsets (line and column) are 0-based. + Lines: start and end are within the bounds + Column: + start column is within the bounds; + end column is after the bounds. This changes behaviour from previous versions of the protocol. Matching PRs in the emacs modes: + idris2-mode [PR#11](https://github.com/idris-community/idris2-mode/pull/11) + idris-mode [PR#547](https://github.com/idris-hackers/idris-mode/pull/547) * The IDE protocol now supports specifying a socket and hostname via the `--ide-mode-socket` flag, allowing multiple IDE server instances to run on the same machine. ### Interactive Editing changes * Case-split no longer generates syntactically invalid Idris when splitting on auto-implicits. * Case-split no longer shadows the function name when an internal named argument has the same name as the function. * Case-split now avoids using upper-case names for pattern variables. ### Library changes #### Prelude * `elemBy` and `elem` are now defined for any `Foldable` structure. The specialised versions defined in `Data.(List/SnocList/Vect)` have been removed. * `filter` and `mapMaybe` functions for `List` were moved to `prelude` from `base`. * Basic functions of `SnocList` (`(++)`, `length`, `filter`, `mapMaybe`) and implementations of `Eq` and `Ord` were moved to `prelude` from `base`. This may lead to a need to qualifying functions (e.g. `List.filter`) due to possible ambiguity. * "Fish" and "chips" operators of `SnocList` were moved to `Prelude.Types` from `Prelude.Basics`. * Adds `contra` for returning the opposite of a given `Ordering`. * Fix `pow`, using backend implementations. * Add `subtract` alias for `(-)` #### Base * Adds `System.run`, which runs a shell command, and returns the stdout and return code of that run. * Adds escaped versions of `System.system`, `Systen.File.popen`, and `System.run`, which take a list of arguments, and escapes them. * Adds the `Injective` interface in module `Control.Function`. * Changes `System.pclose` to return the return code of the closed process. * Deprecates `base`'s `Data.Nat.Order.decideLTE` in favor of `Data.Nat.isLTE`. * Removes `base`'s deprecated `System.Directory.dirEntry`. Use `nextDirEntry` instead. * Removes `base`'s deprecated `Data.String.fastAppend`. Use `fastConcat` instead. * `System.File.Buffer.writeBufferData` now returns the number of bytes that have been written when there is a write error. * `System.File.Buffer.readBufferData` now returns the number of bytes that have been read into the buffer. * Adds the `Data.List.Quantifiers.Interleaving` and `Data.List.Quantifiers.Split` datatypes, used for provably splitting a list into a list of proofs and a list of counter-proofs for a given property. * Properties of the `List1` type were moved from `Data.List1` to `Data.List1.Properties`. * `Syntax.PreorderReasoning` was moved to `base` from `contrib`. * Move the types and functions in `Data.Vect.Quantifiers` to their respective namespaces (`All` for all-related things, and `Any` for any-related things) to make the code consistent with the other quantifiers (`List` and `SnocList`). * Set the `all` and `any` functions for proof-quantifiers to `public export` instead of `export`, allowing them to be used with auto-implicit `IsYes`. * Legacy duplicating type `Given` (with constructor `Always`) is removed from the `Decidable.Decidable`. Use the type `IsYes` (with constructor `ItIsYes`) from the same module instead. * Adds `Data.List1.Elem`, ported from `Data.List.Elem`. * Adds `Data.List1.Quantifiers`, ported from `Data.List.Quantifiers`. * Changes the order of arguments in `RWST` transformer's runners functions (`runRWST`. `evalRWST`, `execRWST`), now transformer argument is the last, as in the other standard transformers, like `ReaderT` and `StateT`. * Adds `Data.Fin.finToNatEqualityAsPointwise`, which takes a witness of `finToNat k = finToNat l` and proves `k ~~~ l`. * Drop first argument (path to the `node` executable) from `System.getArgs` on the Node.js backend to make it consistent with other backends. * Adds `Uninhabited` instances for `FZ ~~~ FS k` and `FS k ~~~ FZ`. * Change behavior of `channelPut` on the Racket backend to match the behavior on the Chez backend. * `fGetLine` has been marked as `covering` instead of `total`. * Adds the ability to derive `Functor` and `Traversable` using `%runElab derive` in the implementation definition. * Fixes memory leaks in `currentDir`, `fGetLine`, and `fGetChars`. * Fixes `natToFinLT` being O(n) by proving that `So (x < n)` implies `LT x n`, allowing the compiler to optimise `natToFinLT` away. * Fixes `SnocList.foldr` and `SnocList.foldMap` to be performant and stack-safe. * Add `insertAt`, `deleteAt` and `replaceAt` for `List` * Add `scanr`, `scanr1` and `unsnoc` for `Vect` * Implement `DecEq` for `SnocList` #### Test * Refactors `Test.Golden.runTest` to use `System.Concurrency` from the base libraries instead of `System.Future` from `contrib`. In addition to reducing the dependency on `contrib` in the core of Idris2, this also seems to provide a small performance improvement for `make test`. * Splits `runner` into `runnerWith` for processing the options and configuring the test pools, and a new `runner` function for reading options from the command-line. #### Contrib * `System.Random` support for `Int` changed to `Int32`; it already limited itself to 32 bits but now that is codified. JavaScript backends are now supported. * Removes `contrib`'s deprecated `Data.Num.Implementations` module. See `Prelude.Interfaces` instead. * Implements `Show tok => Show (ParsingError tok)` for `Text.Parser.Core`. * `Control.Linear.LIO` has been moved from `contribs` to `linear` to guarantee that idris2 does not need to rely on contribs anymore. #### Network * `Control.Linear.Network` now supports `connect` in the linear environment, and can also access the `sendBytes`, `recvBytes` and `recvAllBytes` functions of the underlying `Socket` module. #### Papers, Linear * Creates the `papers` and `linear` libraries to remove bits of type theory and pl propaganda from `contrib` and instead clearly have them as implementations of their respective papers. * Creates `Data.Linear.{Notation,LEither,LMaybe,LVect,Pow}`. * Moves `Data.Container`, based on the papers "Categories of Containers" by Michael Abbott, Thorsten Altenkirch, and Neil Ghani, and "Derivatives of Containers" by Michael Abbott, Thorsten Altenkirch, Neil Ghani, and Conor McBride, to `papers`. [https://doi.org/10.1007/3-540-36576-1_2](https://doi.org/10.1007/3-540-36576-1_2) [https://doi.org/10.1007/3-540-44904-3_2](https://doi.org/10.1007/3-540-44904-3_2) * Moves the implementation of "Indexed induction-recursion" by Dybjer and Setzer to `papers`. [https://doi.org/10.1016/j.jlap.2005.07.001](https://doi.org/10.1016/j.jlap.2005.07.001) * Ports "How to Take the Inverse of a Type" by Daniel Marshall and Dominic Orchard as `Data.Linear.{Communications,Diff,Inverse}`. [https://doi.org/10.4230/LIPIcs.ECOOP.2022.5](https://doi.org/10.4230/LIPIcs.ECOOP.2022.5) * Moves `Data.OpenUnion`, inspired by the paper "Freer monads, more extensible effects" by Oleg Kiselyov and Hiromi Ishii, to `papers`. [https://doi.org/10.1145/2887747.2804319](https://doi.org/10.1145/2887747.2804319) * Moves `Data.Recursion.Free`, partially based on "Turing-Completeness Totally Free" by Conor McBride, to `papers`. [https://doi.org/10.1007/978-3-319-19797-5_13](https://doi.org/10.1007/978-3-319-19797-5_13) * Moves `Data.Tree.Perfect` to `papers`. * Moves `Data.Vect.Binary`, taken from the paper "Heterogeneous Binary Random-access Lists" by Wouter Swierstra, to `papers`. [https://doi.org/10.1017/S0956796820000064](https://doi.org/10.1017/S0956796820000064) * Ports "Applications of Applicative Proof Search" by Liam O'Connor as `Search.{Generator,HDecidable,Negation,Properties,CTL,GCL}`. [https://doi.org/10.1145/2976022.2976030](https://doi.org/10.1145/2976022.2976030) * Implements "Dependent Tagless Final" by Nicolas Biri as `Language.Tagless`. [https://doi.org/10.1145/3498886.3502201](https://doi.org/10.1145/3498886.3502201) * Ports Todd Waugh Ambridge's Agda blog post series "Search over uniformly continuous decidable predicates on infinite collections of types" as `Search.Tychonoff`. [https://www.cs.bham.ac.uk/~txw467/tychonoff/InfiniteSearch1.html](https://www.cs.bham.ac.uk/~txw467/tychonoff/InfiniteSearch1.html) * Ports "Auto in Agda - Programming proof search using reflection" by Wen Kokke and Wouter Swierstra as `Search.Auto`. [https://doi.org/10.1007/978-3-319-19797-5_14](https://doi.org/10.1007/978-3-319-19797-5_14) * Ports "Computing with Generic Trees in Agda" by Stephen Dolan as `Data.W`. [https://doi.org/10.1145/3546196.3550165](https://doi.org/10.1145/3546196.3550165) ### Other changes * Adds docstrings for the lambda-lifted IR. * Package files are now installed along-side build artifacts for installed packages. This means all transitive dependencies of packages you specify with the `depends` field are added automatically. * No longer builds `contrib` and `papers` during bootstrap, as these may rely on new features not yet present in the bootstrap version of Idris2. ## v0.5.0/0.5.1 ### Language changes * Missing methods in implementations now give a compile time error. This was always the intended behaviour, but until now had not been implemented! * Records now work in `parameters` blocks and `where` clauses. * Implementations of interfaces now work in `parameters` blocks and `where` clauses * The syntax for Name reflection has changed, and now requires a single brace instead of a double brace, e.g. `` `{x} `` * Raw string literals allows writing string while customising the escape sequence. Start a string with `#"` in order to change the escape characters to `\#`, close the string with `"#`. Remains compatible with multiline string literals. * Interpolated strings allows inserting expressions within string literals and avoid writing concatenation explicitly. Escape a left curly brace `\{` to start an interpolation slice and close it with a right curly brace `}` to resume writing the string literal. The enclosed expression must be of type `String`. Interpolated strings are compatible with raw strings (the slices need to be escaped with `\#{` instead) and multiline strings. * We now support ellipses (written `_`) on the left hand side of a `with` clause. Ellipses are substituted for by the left hand side of the parent clause i.e. ```idris filter : (p : a -> Bool) -> List a -> List a filter p [] = [] filter p (x :: xs) with (p x) _ | True = x :: filter p xs _ | False = filter p xs ``` means ```idris filter : (p : a -> Bool) -> List a -> List a filter p [] = [] filter p (x :: xs) with (p x) filter p (x :: xs) | True = x :: filter p xs filter p (x :: xs) | False = filter p xs ``` ### Compiler changes * Added incremental compilation, using either the `--inc` flag or the `IDRIS2_INC_CGS` environment variable, which compiles modules incrementally. In incremental mode, the final build step is much faster than in whole program mode (the default), at the cost of runtime performance being about half as good. The `--whole-program` flag overrides incremental compilation, and reverts to whole program compilation. Incremental compilation is currently supported only by the Chez Scheme back end. This is currently supported only on Unix-like platforms (not yet Windows) - Note that you must set `IDRIS2_INC_CGS` when building and installing all libraries you plan to link with an incremental build. - Note also that this is experimental and not yet well tested! * The type checker now tries a lot harder to avoid reducing expressions where it is not needed. This can give a huge performance improvement in programs that potentially do a lot of compile time evaluation. However, sometimes reducing expressions can help in totality and quantity checking, so this may cause some programs not to type check which previously did - in these cases, you will need to give the reduced expressions explicitly. ### REPL/CLI/IDE mode changes * Added `--list-packages` CLI option. * Added `--total` CLI option. ### Library changes #### Prelude Changed - Removed `Data.Strings`. Use `Data.String` instead. #### System.Concurrency * Reimplement the `Channels` primitive in the Chez-Scheme backend since it had some non-deterministic properties (see issue [#1552](https://github.com/idris-lang/idris2/issues/1552)). NOTE: Due to complications with race-conditions, Chez not having channels built-in, etc, the reimplementation changes the semantics slightly: `channelPut` no longer blocks until the value has been received under the `chez` backend, but instead only blocks if there is already a value in the channel that has not been received. With thanks to Alain Zscheile (@zseri) for help with understanding condition variables, and figuring out where the problems were and how to solve them. #### Control.Relation, Control.Order * The old system of interfaces for defining order relations (to say, for instance, that LTE is a partial order) is replaced with a new system of interfaces. These interfaces defines properties of binary relations (functions of type `ty -> ty -> Type`), and orders are defined simply as bundles of these properties. ### Installation changes * Added a new makefile target to install Idris 2 library documentation. After `make install`, type `make install-libdocs` to install it. After that, the index file can be found here: ``idris2 --libdir`/docs/index.html`.`` ## v0.4.0 ### Syntax changes * Desugar non-binding sequencing in do blocks to (`>>`) ([#1095](https://github.com/idris-lang/idris2/pull/1095)) * Multiline Strings with `"""` as delimiters ([#1097](https://github.com/idris-lang/idris2/pull/1097)) * Force strict indentation after usage of `with` keyword ([#1107](https://github.com/idris-lang/idris2/pull/1107)) * The syntax for parameter blocks has been updated. It now allows to declare implicit parameters and give multiplicities for parameters. The old syntax is still available for compatibility purposes but will be removed in the future. * Add support for SnocList syntax: `[< 1, 2, 3]` desugars into `Lin :< 1 :< 2 :< 3` and their semantic highlighting. * Underscores can be used as visual separators for digit grouping purposes in integer literals: `10_000_000` is equivalent to `10000000` and `0b1111_0101_0000` is equivalent to `0b111101010000`. This can aid readability of long literals, or literals whose value should clearly separate into parts, such as bytes or words in hexadecimal notation. ### Compiler changes * Added more optimisations and transformations, particularly on case blocks, list-shaped types, and enumerations, so generated code will often be slightly faster. * Added `--profile` flag, which generates profile data if supported by a back end. Currently supported by the Chez and Racket backends. * New `%builtin` pragma for compiling user defined natural numbers to primitive `Integer`s (see the [docs](https://idris2.readthedocs.io/en/latest/reference/builtins.html)) * The `version` field in `.ipkg` files is now used. Packages are installed into a directory which includes its version number, and dependencies can have version number ranges using `<=`, `<`, `>=`, `>`, `==` to express version constraints. Version numbers must be in the form of integers, separated by dots (e.g. `1.0`, `0.3.0`, `3.1.4.1.5` etc) * Idris now looks in the current working directory, under a subdirectory `depends` for local installations of packages before looking globally. * Added an environment variable `IDRIS2_PACKAGE_PATH` for extending where to look for packages. * Added compiler warnings flags (`-W` prefix): - `-Wno-shadowing`: disable shadowing warnings. - `-Werror`: treat warnings as errors. * Experimental flag (`-Xcheck-hashes`) to check hashes instead of filesystem times to determine if files should be recompiled. Should help with CI/CD caching. ### REPL/IDE mode changes * Added `:search` command, which searches for functions by type * `:load`/`:l` and `:cd` commands now only accept paths surrounded by double quotes * Added a timeout to "generate definition" and "proof search" commands, defaulting to 1 second (1000 milliseconds) and configurable with `%search_timeout <time in milliseconds>` ### Library Changes #### Prelude Added - `Bifoldable` and `Bitraversable` interfaces. - `Foldable` add `foldlM`, `foldMap`, and `toList`. - `Monad` interface `>=>`, `<=<` (Kleisli Arrows), and flipped bind (`=<<`). - `Pair` Applicative and Monad implementations. - `SnocList` datatype (fliped cons of a linked list). - `(.:)` function "blackbird operator" (Composition of a two-argument function with a single-argument one.) - `on` function (Eg, ```((+) `on` f) x y = f x + f y```) Changed - `===`, `~=~`, and `<+>` operator precedence - Exctracted `Cast` interface and implementations from `Prelude.Types` to `Prelude.Cast` - Renamed `Data.Strings` to `Data.String` Hidden - `countFrom` #### Base Added - `Control.Applicative.Const`. - New `Control.Monad` Monad Transformers types. - `Data.Bits`, an interface for bitwise operations. - `Data.Colist` and `Data.Colist1`. - `Data.Contravariant` interface for contravariant functors. - `Data.List` `unzip` function. - `Data.List1` `zip*` and `unzip*` functions. - `Data.SnocList`. - `Data.Stream` `unzipWith` and `unzipWith3` fuctions. - `Data.Vect` `unzipWith` and `unzipWith3` functions. - `System.File` `withFile` and total read functions. Changed: - Restructured Monad Transformers in `Control.Monad` - `zip` precedence #### Contrib Added - `Control.Validation`, a library for dependent types input validation. - `System.Console.GetOpt`, a library for specifying and parsing command line options. #### New test package - Moved `tests/Lib.idr` to package as `Test/Golden.idr`. - Removed `contrib/Test/Golden.idr` which duplicated the test framework now in the `test` package. ### Codegen changes #### Racket * Now always uses `blodwen-sleep` instead of `idris2_sleep` in order to not block the Racket runtime when `sleep` is called. * Redid condition variables in the Racket codegen based on page 5 of the Microsoft [Implementing CVs paper](https://www.microsoft.com/en-us/research/wp-content/uploads/2004/12/ImplementingCVs.pdf). Previously, they were based on an implementation using semaphores and asynchronous channels, which worked apart from `broadcast`. The rework fixes `broadcast` at the cost of losing `wait-timeout` due to increased complexity of their internals and interactions between their associated functions. #### JavaScript * Now use `Number` to represent up to 32 bit precision signed and unsigned integers. `Int32` still goes via `BigInt` for multiplication to avoid precision issues when getting results larger than `Number.MAX_SAFE_INTEGER`. `Bits32` goes via `BigInt` for multiplication for the same reason as well as for all bitops, since `Number` uses signed 32 bit integers for those. * Now use `Number` instead of `BigInt` to represent up to 32 bit fixed precision signed and unsigned integers. This should make interop with the FFI more straight forward, and might also improve performance. #### New chez-sep * This code generator produces many Chez Scheme files and compiles them separately instead of producing one huge Scheme program. This significantly reduces the amount of memory needed to build large programs. Since this backend will skip calling the Chez compiler on modules that haven't changed, it also leads to shorter compilation times in large codebases where only some files have changed -- for example when developing Idris2 code generators. The codegen has a large parallelisation potential but at the moment, it is significantly slower for a full rebuild of a large codebase (the code generation stage takes about 3x longer). ### API changes * The API now exposes `Compiler.Separate.getCompilationUnits`, which can be used for separate code generation by any backend. * New fixed precision signed integer types `Int8`, `Int16`, `Int32`, and `Int64` where added. In addition, all integral types now properly support all arithmetic and bitwise operations. * The compiler now provides primitive cast operations for all combinations of primitives with the exception of going from `Double` to `Char` and back, and going from `String` to `Char`. * A new pragma `%doubleLit` to support overloaded floating point literals was added. ### Other changes * Lots of small performance improvements, some of which may be especially noticeable in programs that do a lot of type level evaluation. * Added HTML documentation generation, using the `--mkdoc` flag * Support for auto-completion in bash-like shells was added. * Fixed case-splitting to respect any indentation there may be in the term being case-split and the surrounding symbols, instead of filtering out the whitespace and putting it back as indentation. ## v0.3.0 Library changes: * Overhaul of the concurrency primitives: - Renamed `System.Concurrency.Raw` to `System.Concurrency`. - Modified the implementation of `Prelude.IO.fork` in the Chez Scheme RTS, which now returns a semaphore instead of a thread object. This allows the main thread to wait for the child thread to finish (see next bullet). The Racket implementation already returned a thread descriptor, which could be used to wait for the thread to finish. - Added `Prelude.IO.threadWait` which waits for a thread, identified by a `ThreadID`, to finish. This operation is supported by both the Chez Scheme and the Racket RTS'es. - Added semaphores to `System.Concurrency`, supported by both the Chez Scheme and Racket RTS'es. - Added barriers to `System.Concurrency`, supported by both the Chez Scheme and Racket RTS'es. - Added synchronous channels to `System.Concurrency`, supported by both the Chez Scheme and Racket RTS'es. - Fixed the support for mutexes in the Racket RTS. Formerly, they were implemented with semaphores, and calling`mutexRelease` multiple times would increment the internal counter multiple times, allowing multiple concurrent `mutexAcquire` operations to succeed simultaneously. Currently, `mutexRelease` fails when called on a mutex which isn't owned. (However, `mutexRelease` does not check whether the mutex is in fact owned by the current thread, which may be a bug.) - Modified the support for condition variables in the Racket RTS. Formerly, they were implemented using synchronous channels, meaning that: + `conditionSignal` was a blocking operation; and + calling `conditionSignal` on a condition variable on which no thread was waiting would wake the next thread to call `conditionWait`, whereas condition variables are supposed to be stateless, and only wake threads already in the queue. The implementation was replaced with an implementation based on asynchronous channels and mutexes, based on the following paper: [Implementing Condition Variables with Semaphores](https://www.microsoft.com/en-us/research/wp-content/uploads/2004/12/ImplementingCVs.pdf) by Andrew Birrell - Removed `threadID` and `blodwen-thisthread`. Formerly, in the Chez Scheme backend, this function returned "the thread ID of the current thread" as a value of type `ThreadID`. However, `fork` returned a "thread object" as a value of type `ThreadID`. These are *different kinds of values* in Chez Scheme. As there was nothing one could do with a value of type `ThreadID`, I chose to remove `threadID`, as it allowed me to implement `threadWait` more easily. - Renamed `blodwen-lock` and `blodwen-unlock` to `blodwen-mutex-acquire` and `blodwen-mutex-release` for consistency, as these functions are referred to with acquire and release both in Chez Scheme and in the Idris2 concurrency module. * Added `Data.HVect` in `contrib`, for heterogeneous vectors. * Various other library functions added throughout `base` and `contrib` Command-line options changes: * Added `--color` and `--no-color` options for colored terminal output. Color is enabled by default. * Added `--console-width <auto|n>` option for printing margins. By default the `auto` option is selected, the result is that the compiler detects the current terminal width and sets it as the option value, otherwise a user value can be provided. An explicit `0` has the effect of simulating a terminal with unbounded width. Language and compiler changes: * Removed multiplicity subtyping, as this is unsound and unfortunately causes more problems than it solves. This means you sometimes now need to write linear versions of functions as special cases. (Though note that the 1 multiplicity is still considered experimental, so hopefully this will change for the better in the future!) * Added new syntax for named applications of explicit arguments: `f {x [= t], x [= t], ...}` `f {x [= t], x [= t], ..., _}` * Added syntax for binding all explicit arguments (in the left hand side); `f {}` * Added new syntax for record updates (without the need for the `record` keyword): `{x := t, x $= t, ...}` * Local implementations of interfaces (in `let` or `where` blocks) now work, along with `%hint` annotations on local definitions, meaning that local definitions can be searched in auto implicit search. + Note, though, that there are still some known limitations (with both local hints and local implementations) which will be resolved in the next version. * New experimental ``refc`` code generator, which generates C with reference counting. * Added primitives to the parsing library used in the compiler to get more precise boundaries to the AST nodes `FC`. REPL/IDE mode changes: * Added `:color (on|off)` option for colored terminal output. * Added `:consolewidth (auto|n)` option for printing margins. Mirrors the command-line option. ## v0.2.1 Language changes: * `Bits8`, `Bits16`, `Bits32` and `Bits64` primitive types added, with: + `Num`, `Eq`, `Ord` and `Show` implementations. + Casts from `Integer`, for literals + Casts to `Int` (except for `Bits64` which might not fit), `Integer` and `String` + Passed to C FFI as `unsigned` + Primitives added in `Data.Buffer` * Elaborator reflection and quoting terms + Requires extension `%language ElabReflection` + API defined in `Language.Reflection`, including functions for getting types of global names, constructors of data types, and adding new top level declarations + Implemented `%macro` function flag, to remove the syntactic noise of invoking elaborator scripts. This means the function must always be fully applied, and is run under `%runElab` * Add `import X as Y` + This imports the module `X`, adding aliases for the definitions in namespace `Y`, so they can be referred to as `Y`. * `do` notation can now be qualified with a namespace + `MyDo.do` opens a `do` block where the `>>=` operator used is `MyDo.(>>=)` Library changes: * `IO` operations in the `prelude` and `base` libraries now use the `HasIO` interface, rather than using `IO` directly. * Experimental `Data.Linear.Array` added to `contrib`, supporting mutable linear arrays with constant time read/write, convertible to immutable arrays with constant time read. + Anything in `Data.Linear` in `contrib`, just like the rest of `contrib`, should be considered experimental with the API able to change at any time! Further experiments in `Data.Linear` are welcome :). * Experimental `Control.Linear.LIO` added to `contrib`, supporting computations which track the multiplicities of their return values, which allows linear resources to be tracked. * Added `Control.Monad.ST`, for update in-place via `STRef` (which is like `IORef`, but can escape from `IO`). Also added `Data.Ref` which provides an interface to both `IORef` and `STRef`. * Added `Control.ANSI` in `contrib`, for usage of ANSI escape codes for text styling and cursor/screen control in terminals. Command-line options changes: * Removed `--ide-mode-socket-with` option. `--ide-mode-socket` now accepts an optional `host:port` argument. * Added options to override source directory, build directory and output directory: `--source-dir`, `--build-dir`, `--output-dir`. + These options are also available as fields in the package description: `sourcedir`, `builddir`, `outputdir`. Compiler changes: * It is now possible to create new backends with minimal overhead. `Idris.Driver` exposes the function `mainWithCodegens` that takes a list of codegens. The feature in documented [here](https://idris2.readthedocs.io/en/latest/backends/custom.html). * New code generators `node` and `javascript`. REPL/IDE mode changes: * Implemented `:module` command, to load a module during a REPL session. * Implemented `:doc`, which displays documentation for a name. * Implemented `:browse`, which lists the names exported by a namespace. * Added `:psnext`, which continues the previous proof search, looking for the next type correct expression + Correspondingly, added the IDE mode command `proof-search-next` (which takes no arguments) * Added `:gdnext`, which continues the previous program search, looking for the next type correct implementation + Correspondingly, added the IDE mode command `generate-def-next` (which takes no arguments) * Improved program search to allow deconstructing intermediate values, and in simple cases, the result of recursive calls. ## v0.2.0 The implementation is now self-hosted. To initialise the build, either use the [bootstrapping version of Idris2](https://github.com/edwinb/Idris2-boot) or build from the generated Scheme, using `make bootstrap`. Language changes: * `total`, `covering` and `partial` flags on functions now have an effect. * `%default <totality status>` has been implemented. By default, functions must be at least `covering` + That is, `%default covering` is the default status. * Fields of records can be accessed (and updated) using the dot syntax, such as `r.field1.field2` or `record { field1.field2 = 42 }`. For details, see [the "records" entry in the user manual](https://idris2.readthedocs.io/en/latest/reference/records.html) * New function flag `%tcinline` which means that the function should be inlined for the purposes of totality checking (but otherwise not inlined). This can be used as a hint for totality checking, to make the checker look inside functions that it otherwise might not. * %transform directive, for declaring transformation rules on runtime expressions. Transformation rules are automatically added for top level implementations of interfaces. * A %spec flag on functions which allows arguments to be marked for partial evaluation, following the rules from "Scrapping Your Inefficient Engine" (ICFP 2010, Brady & Hammond) * To improve error messages, one can use `with NS.name <term>` or `with [NS.name1, NS.name2, ...] <term>` to disable disambiguation for the given names in `<term>`. Example: `with MyNS.(>>=) do ...`. Library additions: * Additional file management operations in `base` * New module in `base` for time (`System.Clock`) * New modules in `contrib` for JSON (`Language.JSON.*`); random numbers (`System.Random`) Compiler updates: * Data types with a single constructor, with a single unerased arguments, are translated to just that argument, to save repeated packing and unpacking. (c.f. `newtype` in Haskell) + A data type can opt out of this behaviour by specifying `noNewtype` in its options list. `noNewtype` allows code generators to apply special handling to the generated constructor/deconstructor, for a newtype-like data type, that would otherwise be optimised away. * 0-multiplicity constructor arguments are now properly erased, not just given a placeholder null value. Other improvements: * Various performance improvements in the typechecker: + Noting which metavariables are blocking unification constraints, so that they only get retried if those metavariables make progress. + Evaluating `fromInteger` at compile time. * Extend Idris2's literate mode to support reading Markdown and OrgMode files. For more details see: ["literate" in the user manual](https://idris2.readthedocs.io/en/latest/reference/literate.html). ## Changes since Idris 1 Everything :). For full details, see: [updates](https://idris2.readthedocs.io/en/latest/updates/updates.html)