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Version 1.42.0 of the Haskell implementation of Dhall is out, which provides several new features:

First, it implements version 23.0.0 of the Dhall standard, including support for Bytes literals.

However, it also includes several additional goodies, like:

• A new dhall package command for creating a package.dhall file from a directory
• A more powerful dhall to-directory-tree command that lets you set file metadata

… and a whole bunch of bug fixes since the last release.

For more details, you can find the full changelog below the fold:

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• Supports standard version 23.0.0
  • BREAKING CHANGE TO THE API AND LANGUAGE: Language support for Bytes literals
    • This is a breaking change to the API due to adding new Bytes and BytesLiteral constructors to the Expr type
    • This is a breaking change to the language now that Bytes is a reserved identifier
  • BREAKING CHANGE TO THE API AND LANGUAGE: New {Date,Time,TimeZone}/show builtins
    • This is a breaking change to the API due to adding new {Date,Time,TimeZone}Show constructors to the Expr type
    • This is a breaking change to the language now that {Date,Time,TimeZone}/show are not reserved identifiers
• BREAKING CHANGE: dhall lint no longer sorts let bindings
  • This had to be removed because the old behavior was not always correct
  • The old behavior would sometimes change the behavior of a Dhall program or break the program
  • Out of an abundance of caution we're disabling the feature until it can be properly fixed (which is't trivial)
• BUG FIX: Fix pretty-printing of Time literals
  • The pretty-printer was stripping leading zeros from the fractional component of seconds
• BUG FIX: Fix custom normalizers to work for things other than functions
  • Before this change you could extend the language with custom functions, but not custom values (e.g. foo = 1)
• BUG FIX: Don't URL encode path components
  • The pretty-printer was URL-encoding path components, which is not correct (according to the standard)
  • URL path components are supposed to be already URL-encoded by the user and left undisturbed by the interpreter (which is now what it correctly does)
• New dhall package command: #2478, #2508
  • This command makes it easier to turn a directory full of Dhall expressions into a dhall package (e.g. package.dhall)
• Improved dhall to-directory-tree subcommand
  • The dhall to-directory-tree subcommand now optionally supports specifying metadata for generated paths
  • For a worked example, see: https://github.com/dhall-lang/dhall-haskell/blob/main/dhall/examples/to-directory-tree.dhall
• dhall freeze --cache --all is now idempotent: #2486, #2500
  • Before this change a second run would fail due to attempting to resolve the missing import it would generate
• New Template Haskell options for adding strictness annotations to generated Haskell types
• Template Haskell can now generate higher-kinded Haskell types from higher-kinded Dhall types
• New Dhall.Freeze utilities for working with custom evaluators
• Add Data instances for Import and various other types
• Add Eq instances for InvalidDecoder and ExtractError