1.5.0

[yannham]

Nickel 1.5 is a major release (albeit not literally), with new core language features and improved LSP. In particular, Nickel 1.5 introduces:

• Full blown pattern matching. Patterns were previously restricted to destructuring let-bindings. They can now be used within match expressions as well (which only supported simple enum tags before).
• Enum variants. Enum variants are a new language constructs which are enum tags with associated data (they are applied to an argument). They can be seen as form of algebraic data types (ADT). Patterns, enum types, typechecking and other parts of the language are extended accordingly to support them.
• Background evaluation in the LSP. The LSP now performs evaluation of the current document in the background to report evaluation errors directly in your editor, and in particular contract errors.
• A new section of the manual on writing modular configurations.

Please refer to the manual for more details on those new features.

Core language

• Allow metadata keywords in field position by @yannham in Allow metadata keywords in field position #1768
• Support other bases than decimal for num literals by @yannham in Support other bases than decimal for num literals #1798
• Enum variants:
  • Structural ADTs: first step by @yannham in Structural ADTs: first step #1770
  • Implement equality on ADTs by @yannham in Implement equality on ADTs #1787
  • Fix laziness closurization bug, add support for ADTs by @yannham in Fix laziness closurization bug, add support for ADTs #1789
  • ADT destructuring by @yannham in ADT destructuring #1812
  • Enum tag destructuring by @yannham in Enum tag destructuring #1813
  • Implement ADT contracts by @yannham in Implement ADT contracts #1821
  • Introduce application syntax for ADTs by @yannham in Introduce application syntax for ADTs #1825
  • Relax enum row conflicts by @yannham in Relax enum row conflicts #1831
  • Properly force enum variants by @yannham in [Fix] Properly force enum variants #1835
  • Fix enum contract stripping unwrapping variant argument by @yannham in [Fix] Fix enum contract stripping unwrapping variant argument #1833
• Pattern matching:
  • [Refactor] Pattern matching by @yannham in [Refactor] Pattern matching #1799
  • Record pattern compilation by @yannham in Record pattern compilation #1816
  • Enum pattern compilation by @yannham in Enum pattern compilation #1817
  • [Refactor] Pattern positions by @yannham in [Refactor] Pattern positions #1819
  • Full pattern matching by @yannham in Full pattern matching #1820
  • Support pattern contracts in match statement by @yannham in Support pattern contracts in match statement #1823
  • Fix the semantics of default values in patterns by @yannham in Fix the semantics of default values in patterns #1826
  • Specialized pattern compilation for enum tags by @yannham in Specialized pattern compilation for enum tags #1846

Stdlib

• Add array.zip_with and array.map_with_index to the standard library by @vkleen in Add array.zip_with and array.imap to the standard library #1797
• fixed std.array.split_at behavior at right boundary. by @suimong in fixed std.array.split_at behavior at right boundary. #1803
• Update stdlib for ADTs by @yannham in Update stdlib for ADTs #1822

Tooling

• LSP: Add "goto definition" support for the import term by @jneem in Add "goto definition" support for the import term #1756
• LSP: Add support for NICKEL_IMPORT_PATH environment variable @jneem in Nls import improvements #1795
• LSP: Improved reference-finding by @jneem in Improved (but possibly expensive) reference-finding #1800
• LSP: rename action by @jneem in Rename LSP action #1811
• LSP: evaluation in the background by @jneem in LSP evaluation in the background #1814
• LSP: Improve document symbols by @jneem in Improve document symbols #1848
• Add more spacing to contract error messages by @yannham in Add more spacing to contract error messages #1767
• Proper error message for non exhaustive match by @yannham in Proper error message for non exhaustive match #1772
• Add InvalidContractError by @yannham in Add InvalidContractError #1824

Documentation

• Add patterns to the syntax section of the manual by @yannham in [Doc] Add patterns to the syntax section of the manual #1832
• Improve the description of identifier syntax in the manual by @vkleen in Improve the description of identifier syntax in the manual #1839
• Add subsection on enum types in the manual by @yannham in Add subsection on enum types in the manual #1836
• Fix old CLI syntax in documentation by @cydparser in Fix documentation #1844
• Add manual section on modular configurations by @yannham in Add manual section on modular configurations #1841
• Update/refresh examples using latest Nickel idioms by @yannham in Update/refresh examples using latest Nickel idioms #1849

Fixes

• Check if stderr is a terminal for error messages by @vkleen in Check if stderr is a terminal for error messages #1766
• correctly drop Array::IntoIter by @Radvendii in correctly drop Array::IntoIter #1773
• LSP: vendor codespan, and fix character offset issues by @jneem in Vendor codespan, and fix character offset issues #1793
• [Fix & Refactor] Row conflict error by @yannham in [Fiix & Refactor] Row conflict error #1808
• Fix unbound identifier when querying in REPL by @yannham in Fix unbound identifier when querying in REPL #1843
• Fix --field not applying pending contracts by @yannham in Fix --field not applying pending contracts #1778

New Contributors

• @cydparser made their first contribution in Fix documentation #1844

Full Changelog: 1.4.1...1.5.0

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This discussion was created from the release 1.5.0.