dhall-haskell/CHANGELOG.md

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