1.11.0

Nickel 1.11 includes a new experimental package manager. It is integrated directly in the normal Nickel binary, but is not enabled by default: you either need to use a package-enabled pre-built binary (ending with -pkg) or build Nickel from source with the feature package-experimental. Please refer to the new package management chapter of the manual for more details.

Nickel 1.11 also includes a number of additions to the stdlib, improvements in tooling (environment variable passing), the stdlib, the contract system, and string interpolation (many cases don't need the explicit std.to_string anymore). See the detailed changelog below for more details.

The large refactoring splitting up the internal representation into two intermediate representations, started a few minor versions ago and paving the ground for a more efficient interpreter, has been completed. Users should not see much difference, although it already leads to better information in the LSP.

Breaking changes

• The typechecking of chains of imports has been modified due to the migration to a new internal intermediate representation. Before, when importing file A in a statically typed block, if the imported file was itself a single import of B, and B contained, say, the number 2, then the typechecker would follow the chain and infer the type Number for the initial import of A. Now, the typechecker only looks at the apparent type of A but doesn't follow imports chains further. If the import expression in A doesn't have a type annotation, as in import "B.ncl", its type will be inferred to be Dyn instead.

  If this breaks your code, the solution is to add missing type annotations to the intermediate imports, here import "B.ncl" : Number.

Core language

• Allow custom contracts to customize the label by @jneem in #2176
• Automatically convert interpolated values to string by @yannham in #2195

Documentation

• Describe customize mode in the CLI chapter of the manual by @yannham in #2219

Stdlib

• Adds a Matches contract to std.string by @jneem in #2172
• Adds a FieldsMatch contract for validating record fields against a regex by @jneem in #2174
• Add std.cast by @jneem in #2184

LSP

• Bump the VSCode extension to 0.4 by @yannham in #2162
• Support pull diagnostics and use them for testing by @jneem in #2166
• ADT and package management improvements in nls by @jneem in #2217

Tooling

• Add support for environment variables sigil @env on the command line by @yannham in #2201
• Experimental package manager:
  • Package management CLI, part 1 by @jneem in #2146
  • Support for index packages by @jneem in #2175
  • Support for index packages with version resolution. by @jneem in #2183
  • Fix error message for bad package ids by @jneem in #2209

Fixes

• Fix panic with multiple contracts on field by @yannham in #2199
• Traverse enum variants by @jneem in #2214