Changelog of @hackage/dhall 1.4.0

1.4.0

  • BREAKING CHANGE TO THE LANGUAGE AND API: You can now supply custom headers for URL imports with the new using keyword
    • This is a breaking change to the language because this adds a new reserved using keyword
    • This is a breaking change to the API because this adds a new field to the URL constructor to store optional custom headers
  • BUG FIX: : is no longer a disallowed path character
    • This was breaking URL imports with a port
  • BUG FIX: If you import a home-anchored path (i.e. ~/foo) and that imports a relative path (like ./bar), then the canonical path of the relative import should be home-anchored (i.e. ~/bar). However, there was a bug that made lose the home anchor (i.e. ./foo/bar), which this release fixes likely fail due to no longer being home-anchored (i.e. `./foob
  • Add support for string interpolation
  • merge no longer requires a type annotation if you are merging at least one alternative
  • Expanded Prelude
    • ./Prelude/Optional/all
    • ./Prelude/Optional/any
    • ./Prelude/Optional/filter
    • ./Prelude/Optional/length
    • ./Prelude/Optional/null
    • ./Prelude/Text/concatMap
    • ./Prelude/Text/concatMapSep
    • ./Prelude/Text/concatSep
  • Rearrange detailed error messages to put summary information at the bottom of the message

1.3.0

  • BREAKING CHANGE TO THE API: Add support for new primitives, specifically:
    • (//) - Right-biased and shallow record merge
    • Optional/build (now a built-in in order to support build/fold fusion)
    • Natural/show
    • Integer/show
    • Double/show
    • Natural/toInteger
    • These all add new constructors to the Expr type, which would break exhaustive pattern matches
  • BREAKING CHANGE TO THE LANGUAGE: Imported paths and URLs no longer support the characters: "()[]{}<>:"
    • This reduces the number of cases where you have to add a space after imports
    • Note that this does not exclude the : in the URL scheme (i.e. http://)
  • Increase connection timeout for imports
  • Variable names now allow the - character for all but the first character
  • You can now escape identifiers with backticks
    • This lets you name identifiers so that they don't conflict with reserved key words
    • This is most useful when converting Dhall to other file formats (like JSON) where you might need to emit a field that conflicts with one of Dhall's reserved keywords
  • New --version flag for the dhall executable

1.2.0

  • BREAKING CHANGE: Add support for customizing derived Interpret instances
    • This is a breaking change to the Dhall library API since this changes the signature of the Interpret class by replacing the auto method with a more general autoWith method. This autoWith now takes an InterpretOptions argument that lets you customize derived field and constuctor names
    • In practice user programs that use the common path will be unaffected by this change
    • This is not a breaking change to the Dhall language
  • BREAKING CHANGE: Type annotations now bind more tightly than lambda abstraction

    • This is a breaking change to the Dhall language. An expression like this:

      λ(x : A) → y : B

      ... used to parenthesized implicitly as:

      (λ(x : A) → y) : T

      ... but is now parenthesized implicitly as:

      λ(x : A) → (y : T)

      This is now consistent with Haskell's precedence and also consistent with the precedence of List and Optional type annotations

    • This change affects programs with an expression like this:

      -- Assuming that `y : B`
λ(x : A) → y : A → B

      The above program would type-check before this change but not type-check after this change. You would you need to fix the above program by either changing the type signature to annotate just the type of y like this:

      λ(x : A) → y : B

      ... or by adding explicit parentheses like this:

      (λ(x : A) → y) : A → B

    • This is not a breaking change to the Dhall library API

  • BREAKING CHANGE: Add support for importing a path's contents as raw Text by adding as Text after the import

    • This is a breaking change to the Dhall language

    • This is technically a breaking change, but is extremely unlikely to affect you program. This only changes the behavior of old programs that had an expression of the form:

      /some/imported/function as Text

      ... where /some/imported/function is an imported function being applied to two arguments, the first of which is a bound variable named as and the second of which is the type Text

    • This is not a breaking change to the Dhall library API

  • BREAKING CHANGE: Add support for importing environment variables using env:VAR syntax

    • This is a breaking change to the Dhall library API since it adds a new Path constructor

    • This also technically a breaking change to the Dhall language but extremely unlikely to affect your program. This only changes the behavior of old programs that had an expression of the form:

      env:VAR

      ... where env was the name of a bound variable and :VAR was a type annotation without spaces around the type annotation operator

      After this change the program would be interpreted as an import of the contents for the environment variable named VAR

  • BREAKING CHANGE: Support importing paths relative to home directory using ~/some/path syntax
    • This is a breaking change to the Dhall library API since it adds a new field to the File constructor indicating whether or not the imported path is relative to the home directory
    • This is not a breaking change to the Dhall language and the new syntax does not override any old syntax
  • Permit trailing commas and bars in record/union syntax
  • Improve location information for parsing errors

1.1.0

  • BREAKING CHANGE: Non-empty lists no longer require a type annotation
    • This is a breaking change to the Haskell library, not the Dhall language
    • This change does not break existing Dhall programs
    • The Expr type was modified in a non-backwards-compatible way
  • Add new exprA parser
  • Add new InvalidType exception if input fails on an invalid Type
  • Improve documentation and tutorial

1.0.2

  • Add support for Nix-style "double single-quote" multi-line string literals
  • Add isNormalized
  • Improve documentation and tutorial
  • Build against wider range of http-client versions

1.0.1

  • Initial release

1.0.0

  • Accidental premature upload to Hackage. This release was blacklisted