Idris2/CHANGELOG_NEXT.md

This CHANGELOG describes the merged but unreleased changes. Please see CHANGELOG for changes to all previously released versions of Idris2. All new PRs should target this file (CHANGELOG_NEXT).

Changelog

[Next version]

Building/Packaging changes

• The Nix flake's buildIdris function now returns a set with executable and library attributes. These supersede the now-deprecated build and installLibrary attributes. executable is the same as build and library is a function that takes an argument determining whether the library should be installed with sourcecode files or not; other than that, library functionally replaces installLibrary.

• The Nix flake's buildIdris executable property (previously build) has been fixed in a few ways. It used to output a non-executable file for NodeJS builds (now the file has the executable bit set). It used to output the default Idris2 wrapper for Scheme builds which relies on utilities not guaranteed at runtime by the Nix derivation; now it rewraps the output to only depend on the directory containing Idris2's runtime support library.

• The Nix flake now exposes the Idris2 API package as idris2Api and Idris2's C support library as support.

Language changes

• Autobind and Typebind modifier on operators allow the user to customise the syntax of operator to look more like a binder. See #3113.

• Fixity declarations without an export modifier now emit a warning in peparation for a future version where they will become private by default.

• Elaborator scripts were made to be able to access the visibility modifier of a definition, via getVis.

Compiler changes

• The compiler now differentiates between "package search path" and "package directories." Previously both were combined (as seen in the idris2 --paths output for "Package Directories"). Now entries in the search path will be printed under an "Package Search Paths" entry and package directories will continue to be printed under "Package Directories." The IDRIS2_PACKAGE_PATH environment variable adds to the "Package Search Paths." Functionally this is not a breaking change.

Backend changes

RefC Backend

• Compiler can emit precise reference counting instructions where a reference is dropped as soon as possible. This allows you to reuse unique variables and optimize memory consumption.

• Fix invalid memory read onf strSubStr.

• Fix memory leaks of IORef. Now that IORef holds values by itself, global_IORef_Storage is no longer needed.

• Pattern matching generates simpler code. This reduces malloc/free and memory consumption. It also makes debugging easier.

• Stopped useless string copying in the constructor to save memory. Also, name generation was stopped for constructors that have tags.

• Special constructors such as Nil and Nothing were eliminated and assigned to NULL.

• Unbox Bits32,Bits16,Bits8,Int32,Int16,Int8. These types are now packed into Value*. Now, RefC backend requires at least 32 bits for pointers. 16-bit CPUs are no longer supported. And we expect the address returned by malloc to be aligned with at least 32 bits. Otherwise it cause a runtime error.

• Rename C function to avoid confliction. But only a part.

NodeJS Backend

• The NodeJS executable output to build/exec/ now has its executable bit set. That file already had a NodeJS shebang at the top, so now it is fully ready to go after compilation.

Library changes

Prelude

Base

• Data.List.Lazy was moved from contrib to base.

• Added an Interpolation implementation for primitive decimal numeric types and Nat.

• Added append (++) for List version of All.

• Moved helpers and theorems from contrib's Data.HVect into base's Data.Vect.Quantifiers.All namespace. Some functions were renamed and some already existed. Others had quantity changes -- in short, there were some breaking changes here in addition to removing the respective functions from contrib. If you hit a breaking change, please take a look at the PR and determine if you simply need to update a function name or if your use-case requires additional code changes in the base library. If it's the latter, open a bug ticket or start a discussion on the Idris Discord to determine the best path forward.

• Deprecate bufferData in favor of bufferData'. These functions are the same with the exception of the latter dealing in Bits8 which is more correct than Int.

• Added an alternative TTImp traversal function mapATTImp' taking the original TTImp at the input along with already traversed one. Existing mapATTImp is implemented through the newly added one. The similar alternative for mapMTTImp is added too.

• Removed need for the runtime value of the implicit argument in succNotLTEpred.

Contrib

• Data.List.Lazy was moved from contrib to base.

• Existing System.Console.GetOpt was extended to support errors during options parsing in a backward-compatible way.

• Moved helpers from Data.HVect to base library's Data.Vect.Quantifiers.All and removed Data.HVect from contrib. See the additional notes in the CHANGELOG under the Library changes/Base section above.

Network

• Add a missing function parameter (the flag) in the C implementation of idrnet_recv_bytes