dhall-1.23.0

• BREAKING CHANGE: Fix marshaling union literals
  • 1.22.0 introduced two separate bugs in marshaling union literals between
    Dhall and Haskell, which this release fixes:
    • Dhall enums did not correctly map onto Haskell enums
    • New-style union literals (i.e. < A : T >.A x) were not correctly
      supported
  • See: #918
  • See: #927
  • See: #936
• BUG FIX: Fix α-normalization
  • Version 1.22.0 introduced a new faster evaluation algorithm, but the new
    algorithm introduced two α-normalization regression, which this release
    fixes
  • The primary effect of this bug was that semantic integrity checks would
    fail for expressions that contain an if/then/else` expression in their
    normal form
  • See: #931
  • See: #938
• BUG FIX: Fix merging of sort-level record types
  • The language standard requires that { a : Kind } ⩓ { b : Kind } is
    valid, which this change fixes
  • See: #891
• BUG FIX: dhall freeze respects the --ascii flag
  • See: #934
• BUG FIX: Don't autocomplete fields for record types
  • This prevents the REPL from expanding { x : T }.<TAB> to { x : T }.x
  • See: #937
• Support MonadFail-related changes in GHC 8.8
  • See: #912
• Add cross flag to simplify cross-compilation
  • This allows the dhall package to be built without using
    TemplateHaskell
  • See: #928
• Increase lines of context for error messages
  • Error messages now provide at least 20 lines of context instead of 3
    before truncating large expressions
  • See: #916
• Add line numbers to error messages
  • The bottom of every Dhall type error includes the original source code,
    which now has line numbers on the left margin
  • See: #919
• Expand lower bounds on megaparsec/transformers-compat dependencies
  • This is to support dhall on Debian Sid
  • See: #939

dhall-1.22.0

• Supports version 7.0.0 of the standard
  • See: https://github.com/dhall-lang/dhall-lang/releases/tag/v7.0.0
• BREAKING CHANGE: Remove deprecated Path type synonym
  • See: #858
• BUG FIX: Correctly parse identifiers beginning with http
  • i.e. httpPort was supposed to be a valid identifier name and now is
  • See: #870
• BUG FIX: Fix dhall encode bug
  • dhall encode bug was generating binary expressions that were valid
    (i.e. they would decode correctly) but were non-standard (i.e. hashing
    them would not match the hash you would normally get from a semantic
    integrity check)
  • Semantic integrity checks were not affected by this bug since they used
    a slightly different code path that generated the correct binary input to
    the hash. Only the dhall decode subcommand was affected
  • See: #859
• BUG FIX: Fix for Dhall.UnionType
  • This fixes some expressions that would previously fail to marshal into
    Haskell, specifically those were the marshalling logic was built using
    the UnionType utilities
  • See: #857
• Feature: New --alpha flag to α-normalize command-line output
  • See: #855
• Performance improvements
  • The normalizer is now much faster
  • See: #876

dhall-1.21.0

• Supports version 6.0.0 of the language standard
  • See: https://github.com/dhall-lang/dhall-lang/releases/tag/v6.0.0
• BREAKING CHANGE: Remove the constructors keyword
  • ... as standardized in version 6.0.0 of the language standard
  • The deprecation cycle is over, so the keyword is no longer supported
  • For more details, see: https://github.com/dhall-lang/dhall-lang/wiki/Migration%3A-Deprecation-of-constructors-keyword
  • See: #829
• BREAKING CHANGE: CBOR-encode only special Doubles as half-floats
  • ... as standardized in version 6.0.0 of the language standard
  • CBOR Doubles except Infinity/-Infinity/NaN/0.0 are now encoded in at
    least 32 bits
  • See: #822
• BREAKING CHANGE: Sort record and union fields when CBOR-encoding
  • Fields and alternatives are now sorted when serialized
  • This does not affect semantic integrity checks, which already sorted these
    fields/alternatives before hashing expressions
  • This does affect the serialization of expressions that have not been
    normalized (e.g. uninterpreted expressions transmitted over the wire)
  • See: #835
• BUG FIX: Fix non-exhaustive pattern match in dhall lint
  • This fixes: Irrefutable pattern failed for pattern Let (l' :| ls') d'
  • This bug would cause dhall lint to fail on some nested let/in
    expressions
  • See: #780
  • See: #784
• BUG FIX: Don't fail if $HOME environment variable is unset
  • The interpreter was incorrectly throwing an exception if HOME was unset
  • The standard requires that implementations should handle the HOME
    environment variable being missing
  • See: #789
• Feature: Remove version tag from semantic integrity check
  • ... as standardized in version 6.0.0 of the language standard
  • This is not a breaking change because this change also includes
    backwards-compatible support for semantic integrity checks produced by
    older versions of the interpreter
• Feature: Support Unicode path components
  • ... as standardized in version 6.0.0 of the language standard
  • You can now use Unicode in path components if they are quoted
  • i.e. ./families/"禺.dhall" is now legal
• Feature: Add Text/show built-in
  • ... as standardized in version 6.0.0 of the language standard
  • You can now convert a Text literal to its equivalent Dhall source code
    (which is itself a Text literal)
  • This comes in handy when using Dhall code to generate JSON or Dhall code
  • See: #811
• Feature: Add --immediate-dependencies/--transitive-dependencies flags for
  dhall resolve
  • You can now retrieve all of your immediate or transitive dependencies as a
    textual list
  • This simplifies integration with other command-line tools (such as file
    watchers)
  • See: #795
  • See: #803
• Feature: dhall freeze now only freezes remote imports by default
  • dhall freeze used to freeze all imports (including local imports and
    environment variables)
  • Now dhall freeze only freezes remote imports by default, which is what
    most users want
  • You can install freeze all imports using the --all flag
  • See: #808
• Feature: :save and :load REPL state
  • :save with no arguments now saves the REPL state to a .dhall-repl-N
    file
  • The file format is a list of dhall repl commands
  • You can use :load to load the saved state back into the REPL
  • See: #807
• Feature: Add :hash command to dhall repl
  • This lets you conveniently hash expressions within the dhall repl
  • See: #806
• Feature: Add --check flag to dhall format
  • Use this to check if the input is already formatted
  • Useful for continuous integration when you want to ensure that all code
    under version control remains formatted
  • See: #810
• Feature: Add UnionInputType builder for InputTypes
  • This is the union analog of RecordInputType, letting you build a
    record explicitly instead of deriving the instance using GHC generics
  • See: #775
• Feature: Add :set/:unset commands to dhall repl
  • You can use these commands to set or unset command-line options
  • Currently only setting/unsetting --explain is supported
• Standards-compliance fixes:
  • See: #779
  • See: #804
  • See: #833
• Documentation fixes:
  • See: #792
  • See: #825
• Test fixes:
  • See: #782
  • See: #836
• Improved error messages:
  • See: #812
  • See: #815
  • See: #824
• Formatting fixes:
  • See: #831
• REPL fixes:
  • See: #837

dhall-1.20.1

• BUG FIX: Fix binary encoding to use correct standard version
  • This fixes computed hashes to correctly match standard version 5.0.0
  • This is not marked as a breaking change since it is a bug fix. The
    1.20.0 release will be blacklisted on Hackage and users should upgrade
    from 1.19.* directly to 1.20.1
  • See: #771

dhall-1.20.0

• Supports version 5.0.0 of the language standard
  • See: https://github.com/dhall-lang/dhall-lang/releases/tag/v5.0.0
• BREAKING CHANGE TO THE LANGUAGE: Implement standardized support for multi-line
  literals
  • This updates the multi-line support to match the standard
  • This is a breaking change because empty lines within the multi-line
    literal now require leading whitespace whereas previously they did not
  • This is also a breaking change because now a newline is required after
    the opening '' quotes whereas previously it was not required
  • If you use dhall format then your multi-line literals already have the
    necessary leading whitespace
• BREAKING CHANGE TO THE LANGUAGE: constructors x = x
  • Now the constructors keyword behaves like an identity function, since
    constructors can already be accessed as fields off the original union
    type.
  • This is a breaking change since any record of terms that contains a
    constructors field will now be a forbidden mixed record of types and
    terms.
  • This is also a breaking change if you annotated the type of what used to
    be a constructors record.
  • dhall lint will now remove the obsolete constructors keyword for you
  • See: #693
  • See: #701
• BREAKING CHANGE TO THE API: Restore Parent constructor for Local type
  • This more closely matches the standard and also enables dhall format to
    produce a leading ../ for imports instead of ./../
  • See: #718
• BUG FIX: Fix type-checking bug for unions
  • The first fix was that the inferred type was wrong for unions where
    alternatives were types or kinds
  • The second fix was that unions that mixed terms/types/kinds were not
    properly rejected
  • See: #763
• BUG FIX: Change how dhall repl handles prior definitions
  • This changes the REPL to handle previous bindings as if they were
    defined using a large let expression instead of adding them to the
    context
  • This fixes some type-checking false negatives
  • See: #729
• Feature: Autocomplete for dhall repl
  • You can now auto-complete record fields, union constructors, and
    identifiers that are in scope
  • See: #727
• Feature: GHCJS support
  • dhall can now be built using GHCJS, although some features are still
    not supported for GHCJS, such as:
    • Semantic integrity checks
    • Custom HTTP headers
  • Also, HTTP imports only work for URLs that support CORS
  • See: #739
• Feature: Add support for records of records of types
  • You can now nest records of types
  • See: #700
• Feature: Add :quit command for dhall repl
  • See: #719
• Feature: Add --json flag for dhall {encode,decode}
  • You can now produce/consume CBOR expressions via JSON instead of binary
  • See: #717
• Feature: Add decoding logic for as Text
  • You can now preserve the as Text qualifier on imports when serializing
    them
  • See: #712
• Prenormalize substituted expressions
  • This is a performance improvement that reduces the time and memory
    consumption when normalizing expressions
  • See: #765

dhall-1.19.1

dhall-1.19.1

• BUG FIX: Fix serious dhall lint bug
  • dhall lint would sometimes remove let expressions that were still
    in use
  • See: #703
• BUG FIX: Fix import caching efficiency bug
  • Some imports were being wastefully fetched multiple times
  • See: #702
• Feature: Generate dot graph to visualize import graph
  • Use the dhall resolve --dot command
  • See: #698
  • See: #713
• Improve HTTP error messages
  • See: #710

dhall-1.19.0

dhall-1.19.0

• Supports version 4.0.0 of the language standard
  • See: https://github.com/dhall-lang/dhall-lang/releases/tag/v4.0.0
• BREAKING CHANGE TO THE LANGUAGE AND API: Prevent Hurkens' paradox
  • This fixes a type-checking soundness bug which permitted infinite loops
  • This is a breaking change because infinite loops are no longer possible
  • This is also a breaking change because a record of types is now treated as
    a kind instead of a type
  • See: #680
• BREAKING CHANGE TO THE LANGUAGE AND API: Doubles are now double-precision
  floating point numbers
  • This restricts the range of Doubles to IEEE 754 double-precision
    floating point
  • This also implies that you can no longer convert Scientific values to
    Dhall expressions (i.e. no Inject instance for Scientific)
  • See: #667
• BREAKING CHANGE TO THE API: Preserve field order for record projection
  • The API uses a new Dhall.Set.Set type instead of Data.Set.Set
  • See: #670
• BREAKING CHANGE TO THE API: Add support for multi-let expressions
  • This changes the Let constructor to now support storing multiple
    bindings per let expression
  • See: #675
• Access constructors as if they were fields of the union type
  • In other words: < Left : Bool | Right : Natural >.Left
  • See: #657
• Support GHC 8.6
  • See: #669
• Add support for quoted path components
  • i.e. /"foo"/bar/"baz qux" or https://example.com/foo/"bar?baz"?qux
  • See: #690
• Fix parsing of //\\ operator
  • See: 9d0fd42
• Preserve Unicode characters when formatting code
  • See: #679
• Allow identifier names to begin with Some
  • See: #658
• Add subExpressions Traversal
  • See: #660
• Add normalizeWithM for monadic normalization
  • See: #371
• Custom normalizers now take precedence over default normalization logic
  • This allows one to override the implementation of built-in operators
  • See: #684

dhall-json-1.2.5

• Build against dhall-1.19.0
  • See: #667
  • See: #675
  • See: #689

dhall-1.18.0

• Supports version 3.0.0 of the language standard:
  • See: https://github.com/dhall-lang/dhall-lang/releases/tag/v3.0.0
• BREAKING CHANGE TO THE LANGUAGE AND API: New Some/None constructors for
  Optional values
  • Example: [ Some 1, None Natural ]
  • This is a breaking change to the language because Some and None are
    now reserved keywords
  • This is a breaking change to the API because Some and None are new
    constructors for the Expr type
• BREAKING CHANGE TO THE LANGUAGE AND API: Support for kind polymorphism
  • This adds a new Sort constant above Kind in the hierarchy
  • i.e. Type : Kind : Sort
  • This is a breaking change to the language because Sort is now a
    reserved keyword
  • This is a breaking change to the API because Sort is a new
    constructor for the Expr type
• BREAKING CHANGE TO THE API: New Dhall.Map module
  • This replaces InsOrdHashMap in the API
  • The primary motivation is to improve performance and to remove the
    dependency on insert-ordered-containers
• BREAKING CHANGE TO THE API: Use standard version instead of protocol version
  • The binary protocol is now versioned alongside the standard
  • The ProtocolVersion type is renamed to StandardVersion and the
  • --protocol-version option is renamed to --standard-version
  • See: #634
• BUG FIX: Fix import chaining for custom header imports
  • See: #618
• BUG FIX: Fix import chaining for imports protected by semantic integrity
  checks
  • See: #584
• BUG FIX: Record literals and types produced by ∧/⫽/⩓ are now sorted
  • This ensures that β-normalization is idempotent
  • See: #572
• BUG FIX: dhall freeze now correctly handles the starting file being
  located outside the current working directory
  • See: a22aa79
• BUG FIX: Fix parsing of IPv4-mapped IPv6 addresses
  • See: #632
• FEATURE: New --ascii flag for ASCII output
  • See: #570
• FEATURE: New dhall encode and dhall decode subcommands
  • These allow you to transform Dhall source code to and from its binary
    representation
  • See: #588
• LARGE parsing performance improvements
  • Parsing is about 10x-100x faster on most code
  • See: #591
  • See: #592
  • See: #597
  • See: #601
  • See: #602
  • See: #604
  • See: #606
• Type-checking performance improvements:
  • See: #566
• Normalization performance improvements:
  • See: #610
• dhall freeze now caches the imports as it freezes them
  • See: #587
• dhall freeze now refreezes imports with invalid semantic integrity checks
  • See: #637
• dhall freeze now adds a trailing newline
  • See: #629
• Build against megaparsec-7.0.*
  • See: #565
• Support GHC 8.6
  • See: #599
  • See: #623
• Support GHC all the way back to 7.10.3
  • See: #595
  • See: #621
• Improvements to error messages:
  • See: #563
  • See: #576
  • See: #583
  • See: #589

dhall-1.17.0

• This release corresponds to version 2.0.0 of the language standard
• BREAKING CHANGE TO THE LANGUAGE AND API: Binary serialization support
  • This is a breaking change to the hash for all semantic integrity checks
  • The hash used by the semantic integrity check is now based on the
    binary representation instead of a text representation of the
    expression
  • You can pin the new hashes by supplying the --protocol-version 1.0
    option on the command line until you need support for newer language
    features
  • This also includes a breaking change to ImportType in the API
• BREAKING CHANGE TO THE LANGUAGE: Disallow combining records of terms and
  types
  • This is mainly for consistency and to improve type errors that would
    have otherwise happened further downstream
  • This should not affect the vast majority of code
  • See: #538
• BUG FIX: Semantic integrity checks now work for imported expression using
  the constructors keyword
  • See: #554
• BUG FIX: Fix α-normalization of expressions with bound variables named _
  • See: #524
• BUG FIX: Fix isNormalized to match normalize
  • See: #522
• BUG FIX: dhall lint now correctly handles nested let expressions
  • See: #555
• FEATURE: Imports protected by a semantic integrity check are now cached
  • See: #533
• The default dhall command no longer outputs the type to stderr
  • You can add back the type as a type annotation using the
    --annotate switch
  • See: #544
• New utilities for building InputTypes
  • See: #530
• Improve parsing performance for long variable names
  • See: #526
• More succinct type diffs for function types
  • See: #540
• Identifier names can now begin with keywords
  • i.e. ifChanged and lettuce are now legal identifiers
  • See: #551

dhall-1.16.1

• Fix test failure due to missing test data file