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: https://github.com/dhall-lang/dhall-haskell/pull/918
  • See: https://github.com/dhall-lang/dhall-haskell/pull/927
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/931
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/891
• BUG FIX: dhall freeze respects the --ascii flag
  • See: https://github.com/dhall-lang/dhall-haskell/pull/934
• BUG FIX: Don't autocomplete fields for record types
  • This prevents the REPL from expanding { x : T }.<TAB> to { x : T }.x
  • See: https://github.com/dhall-lang/dhall-haskell/pull/937
• Support MonadFail-related changes in GHC 8.8
  • See: https://github.com/dhall-lang/dhall-haskell/pull/912
• Add cross flag to simplify cross-compilation
  • This allows the dhall package to be built without using TemplateHaskell
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/919
• Expand lower bounds on megaparsec/transformers-compat dependencies
  • This is to support dhall on Debian Sid
  • See: https://github.com/dhall-lang/dhall-haskell/pull/939

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: Add support for empty alternatives
  • The Union type now has an optional (Maybe) type for each alternative
  • See the changelog for standard version 7.0.0 for more details
  • See: https://github.com/dhall-lang/dhall-haskell/pull/863
• BREAKING CHANGE: Remove support for URL fragments
  • The URL type no longer has a field for a URL fragment since the language no longer supports fragments
  • See the changelog for standard version 7.0.0 for more details
  • See: https://github.com/dhall-lang/dhall-haskell/pull/851
• BREAKING CHANGE: Remove deprecated Path type synonym
  • See: https://github.com/dhall-lang/dhall-haskell/pull/858
• BUG FIX: Correctly parse identifiers beginning with http
  • i.e. httpPort was supposed to be a valid identifier name and now is
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/857
• Feature: New --alpha flag to α-normalize command-line output
  • See: https://github.com/dhall-lang/dhall-haskell/pull/855
• Performance improvements
  • The normalizer is now much faster
  • See: https://github.com/dhall-lang/dhall-haskell/pull/876

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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/780
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/795
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/807
• Feature: Add :hash command to dhall repl
  • This lets you conveniently hash expressions within the dhall repl
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/779
  • See: https://github.com/dhall-lang/dhall-haskell/pull/804
  • See: https://github.com/dhall-lang/dhall-haskell/pull/833
• Documentation fixes:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/792
  • See: https://github.com/dhall-lang/dhall-haskell/pull/825
• Test fixes:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/782
  • See: https://github.com/dhall-lang/dhall-haskell/pull/836
• Improved error messages:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/812
  • See: https://github.com/dhall-lang/dhall-haskell/pull/815
  • See: https://github.com/dhall-lang/dhall-haskell/pull/824
• Formatting fixes:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/831
• REPL fixes:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/837

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: https://github.com/dhall-lang/dhall-haskell/pull/771

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: https://github.com/dhall-lang/dhall-haskell/pull/693
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/729
• Feature: Autocomplete for dhall repl
  • You can now auto-complete record fields, union constructors, and identifiers that are in scope
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/739
• Feature: Add support for records of records of types
  • You can now nest records of types
  • See: https://github.com/dhall-lang/dhall-haskell/pull/700
• Feature: Add :quit command for dhall repl
  • See: https://github.com/dhall-lang/dhall-haskell/pull/719
• Feature: Add --json flag for dhall {encode,decode}
  • You can now produce/consume CBOR expressions via JSON instead of binary
  • See: https://github.com/dhall-lang/dhall-haskell/pull/717
• Feature: Add decoding logic for as Text
  • You can now preserve the as Text qualifier on imports when serializing them
  • See: https://github.com/dhall-lang/dhall-haskell/pull/712
• Prenormalize substituted expressions
  • This is a performance improvement that reduces the time and memory consumption when normalizing expressions
  • See: https://github.com/dhall-lang/dhall-haskell/pull/765

1.19.1

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

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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/675
• Access constructors as if they were fields of the union type
  • In other words: < Left : Bool | Right : Natural >.Left
  • See: https://github.com/dhall-lang/dhall-haskell/pull/657
• Support GHC 8.6
  • See: https://github.com/dhall-lang/dhall-haskell/pull/669
• Add support for quoted path components
  • i.e. /"foo"/bar/"baz qux" or https://example.com/foo/"bar?baz"?qux
  • See: https://github.com/dhall-lang/dhall-haskell/pull/690
• Fix parsing of //\\ operator
  • See: https://github.com/dhall-lang/dhall-haskell/commit/9d0fd42d95ab69fa64da4afd8b60d69aca8e65a6
• Preserve Unicode characters when formatting code
  • See: https://github.com/dhall-lang/dhall-haskell/pull/679
• Allow identifier names to begin with Some
  • See: https://github.com/dhall-lang/dhall-haskell/pull/658
• Add subExpressions Traversal
  • See: https://github.com/dhall-lang/dhall-haskell/pull/660
• Add normalizeWithM for monadic normalization
  • See: https://github.com/dhall-lang/dhall-haskell/pull/371
• Custom normalizers now take precedence over default normalization logic
  • This allows one to override the implementation of built-in operators
  • See: https://github.com/dhall-lang/dhall-haskell/pull/684

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: https://github.com/dhall-lang/dhall-haskell/pull/634
• BUG FIX: Fix import chaining for custom header imports
  • See: https://github.com/dhall-lang/dhall-haskell/pull/618
• BUG FIX: Fix import chaining for imports protected by semantic integrity checks
  • See: https://github.com/dhall-lang/dhall-haskell/pull/584
• BUG FIX: Record literals and types produced by ∧/⫽/⩓ are now sorted
  • This ensures that β-normalization is idempotent
  • See: https://github.com/dhall-lang/dhall-haskell/pull/572
• BUG FIX: dhall freeze now correctly handles the starting file being located outside the current working directory
  • See: https://github.com/dhall-lang/dhall-haskell/commit/a22aa79d1957be9ecf166ea066e2a9a5b309e1ae
• BUG FIX: Fix parsing of IPv4-mapped IPv6 addresses
  • See: https://github.com/dhall-lang/dhall-haskell/pull/632
• FEATURE: New --ascii flag for ASCII output
  • See: https://github.com/dhall-lang/dhall-haskell/pull/570
• FEATURE: New dhall encode and dhall decode subcommands
  • These allow you to transform Dhall source code to and from its binary representation
  • See: https://github.com/dhall-lang/dhall-haskell/pull/588
• LARGE parsing performance improvements
  • Parsing is about 10x-100x faster on most code
  • See: https://github.com/dhall-lang/dhall-haskell/pull/591
  • See: https://github.com/dhall-lang/dhall-haskell/pull/592
  • See: https://github.com/dhall-lang/dhall-haskell/pull/597
  • See: https://github.com/dhall-lang/dhall-haskell/pull/601
  • See: https://github.com/dhall-lang/dhall-haskell/pull/602
  • See: https://github.com/dhall-lang/dhall-haskell/pull/604
  • See: https://github.com/dhall-lang/dhall-haskell/pull/606
• Type-checking performance improvements:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/566
• Normalization performance improvements:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/610
• dhall freeze now caches the imports as it freezes them
  • See: https://github.com/dhall-lang/dhall-haskell/pull/587
• dhall freeze now refreezes imports with invalid semantic integrity checks
  • See: https://github.com/dhall-lang/dhall-haskell/pull/637
• dhall freeze now adds a trailing newline
  • See: https://github.com/dhall-lang/dhall-haskell/pull/629
• Build against megaparsec-7.0.*
  • See: https://github.com/dhall-lang/dhall-haskell/pull/565
• Support GHC 8.6
  • See: https://github.com/dhall-lang/dhall-haskell/pull/599
  • See: https://github.com/dhall-lang/dhall-haskell/pull/623
• Support GHC all the way back to 7.10.3
  • See: https://github.com/dhall-lang/dhall-haskell/pull/595
  • See: https://github.com/dhall-lang/dhall-haskell/pull/621
• Improvements to error messages:
  • See: https://github.com/dhall-lang/dhall-haskell/pull/563
  • See: https://github.com/dhall-lang/dhall-haskell/pull/576
  • See: https://github.com/dhall-lang/dhall-haskell/pull/583
  • See: https://github.com/dhall-lang/dhall-haskell/pull/589

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: https://github.com/dhall-lang/dhall-haskell/pull/538
• BUG FIX: Semantic integrity checks now work for imported expression using the constructors keyword
  • See: https://github.com/dhall-lang/dhall-haskell/pull/554
• BUG FIX: Fix α-normalization of expressions with bound variables named _
  • See: https://github.com/dhall-lang/dhall-haskell/pull/524
• BUG FIX: Fix isNormalized to match normalize
  • See: https://github.com/dhall-lang/dhall-haskell/pull/522
• BUG FIX: dhall lint now correctly handles nested let expressions
  • See: https://github.com/dhall-lang/dhall-haskell/pull/555
• FEATURE: Imports protected by a semantic integrity check are now cached
  • See: https://github.com/dhall-lang/dhall-haskell/pull/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: https://github.com/dhall-lang/dhall-haskell/pull/544
• New utilities for building InputTypes
  • See: https://github.com/dhall-lang/dhall-haskell/pull/530
• Improve parsing performance for long variable names
  • See: https://github.com/dhall-lang/dhall-haskell/pull/526
• More succinct type diffs for function types
  • See: https://github.com/dhall-lang/dhall-haskell/pull/540
• Identifier names can now begin with keywords
  • i.e. ifChanged and lettuce are now legal identifiers
  • See: https://github.com/dhall-lang/dhall-haskell/pull/551

1.16.1

• Fix test failure due to missing test data file

1.16.0

• BREAKING CHANGE: Consolidate input family of functions
  • These now take a record of options
  • This also _stack field of the Status type from [Import] to NonEmpty Import
• Permit $ in quoted variable names
  • See: https://github.com/dhall-lang/dhall-haskell/pull/510

1.15.1

• Fix infinite loop when formatting expressions containing ?
  • See: https://github.com/dhall-lang/dhall-haskell/pull/491

1.15.0

• BREAKING CHANGE TO THE API: Support alternative imports using new ? operator
  • This adds a new constructor which affects exhaustive pattern matches
  • See: https://github.com/dhall-lang/dhall-haskell/pull/473
• BREAKING CHANGE TO THE API: Add Integer/toDouble built-in function
  • This adds a new constructor which affects exhaustive pattern matches
  • See: https://github.com/dhall-lang/dhall-haskell/pull/434
• BREAKING CHANGE TO THE API: Use strict Text instead of lazy Text
  • See: https://github.com/dhall-lang/dhall-haskell/pull/455
• BREAKING CHANGE TO THE API: Remove Buildable in favor of Pretty
  • See: https://github.com/dhall-lang/dhall-haskell/pull/459
• BREAKING CHANGE TO THE API: Removed the Parent constructor from FilePrefix
  • Instead, use Here with a ".." prefix.
  • See: https://github.com/dhall-lang/dhall-haskell/pull/407
• BUG FIX: Disallow duplicate fields in records
  • See: https://github.com/dhall-lang/dhall-haskell/pull/430
• BUG FIX: Fix stripping of leading whitespace in multi-line strings
  • See: https://github.com/dhall-lang/dhall-haskell/pull/469
• BUG FIX: Fix formatting field access of an import
  • See: https://github.com/dhall-lang/dhall-haskell/pull/471
• Add dhall freeze command
  • See: https://github.com/dhall-lang/dhall-haskell/pull/486
• Add dhall diff command
  • See: https://github.com/dhall-lang/dhall-haskell/pull/442
• Add dhall lint command
  • See: https://github.com/dhall-lang/dhall-haskell/pull/484
• Change dhall-repl/dhall-hash/dhall-format to dhall subcommands
  • i.e. dhall repl/dhall hash/dhall format
  • See: https://github.com/dhall-lang/dhall-haskell/pull/435
  • See: https://github.com/dhall-lang/dhall-haskell/pull/452
• Add with-http cabal flag to disable support for remote imports
  • See: https://github.com/dhall-lang/dhall-haskell/pull/482
• Added inputFrom and inputFromWith
  • These allow naming the file that the expression is coming from for better error messages
  • See: https://github.com/dhall-lang/dhall-haskell/pull/464
• Performance improvements
  • See: https://github.com/dhall-lang/dhall-haskell/pull/420
• Tutorial recommends GitHub for Prelude instead of IPFS
  • See: https://github.com/dhall-lang/dhall-haskell/pull/479
• Pretty-print expressions in type errors
  • See: https://github.com/dhall-lang/dhall-haskell/pull/429
• Formatting improvements
  • See: https://github.com/dhall-lang/dhall-haskell/pull/398
  • See: https://github.com/dhall-lang/dhall-haskell/pull/458
• Diff improvements
  • See: https://github.com/dhall-lang/dhall-haskell/pull/455
  • See: https://github.com/dhall-lang/dhall-haskell/pull/470
  • See: https://github.com/dhall-lang/dhall-haskell/pull/478

1.14.0

• BREAKING CHANGE TO THE LANGUAGE: Switch grammar of Natural and Integer
  • Natural number literals are now unsigned and Integer literals always require a sign
  • This is a VERY disruptive change to most Dhall code in the wild but was unanimously agreed upon here: https://github.com/dhall-lang/dhall-lang/issues/138
  • See also: https://github.com/dhall-lang/dhall-haskell/pull/381
• BREAKING CHANGE TO THE LANGUAGE: Drop support for importing directories
  • Importing dir/ used to resolve to dir/@, which is no longer supported
  • See: https://github.com/dhall-lang/dhall-haskell/pull/384
• BREAKING CHANGE TO THE LANGUAGE: Change to the grammar for imports
  • File path components can no longer contain # or ? characters
  • URL imports must now contain at least one path component
  • URL path components must match the grammar for file path components
  • See: https://github.com/dhall-lang/dhall-haskell/pull/390
• BREAKING CHANGE TO THE API: Rename Path{,Mode,Hashed,Type} to Import{,Mode,Hashed,Type}
  • In practice this change is not breaking for the most common use cases since this also provides a Path type synonym for backwards compatibility
  • See: https://github.com/dhall-lang/dhall-haskell/pull/376
• BUG FIX: Fix α-equivalence bug when type-checking merge
  • merge expressions would sometimes reject valid code due to a type-checking bug
  • See: https://github.com/dhall-lang/dhall-haskell/pull/394
• Improve import caching
  • See: https://github.com/dhall-lang/dhall-haskell/pull/388
  • See: https://github.com/dhall-lang/dhall-haskell/pull/392
• Increase upper bound on tasty
  • See: https://github.com/dhall-lang/dhall-haskell/pull/382
• Fix lower bound on insert-ordered-containers
  • See: https://github.com/dhall-lang/dhall-haskell/pull/377

1.13.1

• Increase upper bound on ansi-terminal and megaparsec

1.13.0

• BUG FIX: Fix semantic integrity hashing support
  • Both parsing and pretty-printing semantic hashes were broken since version 1.11.0
  • See: https://github.com/dhall-lang/dhall-haskell/pull/345
• BUG FIX: Allow leading whitespace in interpolated expresssions
  • See: https://github.com/dhall-lang/dhall-haskell/pull/369
• BUG FIX: Fix deriving (Interpret) for sum types
  • The types of alternatives were not correctly included in the corresponding Dhall type
  • See: https://github.com/dhall-lang/dhall-haskell/pull/348
• BREAKING CHANGE TO LANGUAGE: Records cannot store both types and terms
  • Records can also not store type-level functions (like List)
    • Records might be allowed to store type-level functions again in the future
  • This fixes a potential soundness bug
  • The primarily practical consequence of this change is that if you are hosting a "package" then you will need to split terms and types from your package into different records for your users to import
  • This also implies removing the ./Monoid type-level function from the ./Prelude/package.dhall record
  • See: https://github.com/dhall-lang/dhall-haskell/pull/335
• BREAKING CHANGE TO THE API: Replace trifecta with megaparsec
  • This change the API to use the Parser type from megaparsec
  • This also slightly changes the type of exprFromText
  • If you program using the type classes provided by the parsers library then this is not a breaking change as that interface is preserved
  • See: https://github.com/dhall-lang/dhall-haskell/pull/268
• BREAKING CHANGE TO THE API: New ⩓ operator for merging record types
  • Example: { foo : Text } ⩓ { bar : Bool } = { foo : Text, bar : Bool }
  • This is breaking because it adds a new constructor to the Expr type
  • See: https://github.com/dhall-lang/dhall-haskell/pull/342
• BREAKING CHANGE TO THE API: New support for projecting a subset of fields
  • Example: { x = 1, y = 2, z = 3 }.{ x, y } = { x = 1, y = 2 }
  • This is breaking because it adds a new constructor to the Expr type
  • See: https://github.com/dhall-lang/dhall-haskell/pull/350
• API+UX feature: New support for pretty-printing diffs of Dhall expressions
  • Error messages also use this feature to simplify large type mismatches
  • There is also a new Dhall.Diff module
  • See: https://github.com/dhall-lang/dhall-haskell/pull/336
• Add version, resolve, type, and normalize sub-commands to interpreter
  • See: https://github.com/dhall-lang/dhall-haskell/pull/352
• Support GHC 7.10.3
  • See: https://github.com/dhall-lang/dhall-haskell/pull/340
• :type command in dhall-repl now only displays the type
  • Before it would also display the original expression
  • See: https://github.com/dhall-lang/dhall-haskell/pull/344
• Trim dependency tree
  • See: https://github.com/dhall-lang/dhall-haskell/pull/351
  • See: https://github.com/dhall-lang/dhall-haskell/pull/268
  • See: https://github.com/dhall-lang/dhall-haskell/pull/355

1.12.0

• Additional changes to support GHC 8.4
  • See: https://github.com/dhall-lang/dhall-haskell/pull/331
• BREAKING CHANGE TO API: Replace dependency on text-format with formatting
  • This replace the Data.Text.Buildable.Buildable instances with Formatting.Buildable.Buildable instances, which is why this is a breaking change
  • text-format is no longer maintained and blocking GHC 8.4 support
  • See: https://github.com/dhall-lang/dhall-haskell/pull/330

1.11.1

• Support GHC 8.4
  • See: https://github.com/dhall-lang/dhall-haskell/pull/321
• Fix α-normalization bug
  • Note that this is not a type-checking bug. This only affects users who were directly using the alphaNormalize function from the Haskell API because let expressions were not correctly α-normalized
  • See: https://github.com/dhall-lang/dhall-haskell/pull/319
• Slight tweak to syntax highlighting
  • See: https://github.com/dhall-lang/dhall-haskell/pull/324
• Increase upper bound on ansi-terminal and exceptions
  • See: https://github.com/dhall-lang/dhall-haskell/pull/322
  • See: https://github.com/dhall-lang/dhall-haskell/pull/325

1.11.0

• BREAKING CHANGE TO THE API: Fix {Natural,Optional,List}/build semantics to match standard
  • This is a breaking change because the OptionalLit and ListLit constructors changed their representations to efficiently support the standard semantics
  • ListLit now stores a Data.Sequence.Seq instead of a Data.Vector.Vector
  • OptionalLit now stores a Maybe instead of a Data.Vector.Vector
  • See: https://github.com/dhall-lang/dhall-haskell/pull/300
• BREAKING CHANGE TO THE COMMAND LINE: dhall executable always formats output
  • Previously you had to opt into formatting using --pretty
  • Now formatting is obligatory and the --pretty flag is gone
  • See: https://github.com/dhall-lang/dhall-haskell/pull/303
• Feature: New :save command for dhall-repl
  • Now you can save an expression to a file: ./yourFile = someExpression
  • See: https://github.com/dhall-lang/dhall-haskell/pull/309
• Improvement: Add new simplifications to match standard
  • See: https://github.com/dhall-lang/dhall-haskell/pull/312
  • See: https://github.com/dhall-lang/dhall-haskell/pull/316
• Improvement: Fix equivalence check to match standard
  • Practically this means that more corner cases of the language correctly type-check than before
• Improvement: New --plain flag to disable syntax highlighting
  • See: https://github.com/dhall-lang/dhall-haskell/pull/310
• Improvement: Prelude now provides an umbrella package.dhall import
  • This is primarily for convenience
  • See: https://github.com/dhall-lang/dhall-haskell/pull/298
• Improvement: Context is now normalized
  • See: https://github.com/dhall-lang/dhall-haskell/pull/302
• Replace cryptohash dependency with cryptonite
  • See: https://github.com/dhall-lang/dhall-haskell/commit/5d2012927a062ec8bdf2bbaba77150344f38db77
• Increase upper bound on exceptions
  • See: https://github.com/dhall-lang/dhall-haskell/pull/306
• Fix type error in tutorial
  • See: https://github.com/dhall-lang/dhall-haskell/commit/5a9126b2f684d3236fc1e8e20e206cfaf47d97db

1.10.0

• Feature: Records/unions can now have fields/alternatives that are types
  • i.e. { foo = Text, bar = List } is legal now
  • See: https://github.com/dhall-lang/dhall-haskell/pull/273
• Feature: New dhall-repl for interactively evaluating Dhall expressions
  • See: https://github.com/dhall-lang/dhall-haskell/pull/266
• Feature: Syntax highlighting
  • See: https://github.com/dhall-lang/dhall-haskell/pull/260
• Feature: BREAKING CHANGE TO THE API: dhall-format preserves field order
  • This changes the syntax tree to use an InsOrdHashMap instead of a Map
• BREAKING CHANGE TO THE API: Use Haskell's Scientific type
  • This is fixes the interpreter to correct handle really large/small numbers
  • This also allows marshaling into Haskell's Scientific type
  • See: https://github.com/dhall-lang/dhall-haskell/pull/256
• BREAKING CHANGE TO THE API: Remove system-filepath/system-fileio dependencies
  • Now the library uses Prelude.FilePath
  • See: https://github.com/dhall-lang/dhall-haskell/pull/248
• Feature: Labels can now begin with reserved names
  • i.e. List/map is now a legal label
  • See: https://github.com/dhall-lang/dhall-haskell/pull/255
• Fix: Rendered labels are now correctly escaped if they are numbers
  • See: https://github.com/dhall-lang/dhall-haskell/pull/252
• Add the instance Interpret String.
  • See: https://github.com/dhall-lang/dhall-haskell/pull/247
• Fix: Custom contexts passed to typeWith are now checked
  • This prevents a custom context from triggering an infinite loop
  • See: https://github.com/dhall-lang/dhall-haskell/pull/259

1.9.1

• dhall-format now emits single-quoted strings for multi-line strings
  • See: https://github.com/dhall-lang/dhall-haskell/pull/237
• Improved error messages for list elements with the wrong type
  • See: https://github.com/dhall-lang/dhall-haskell/pull/236
• Change lens dependency to lens-family-core
  • See: https://github.com/dhall-lang/dhall-haskell/pull/238

1.9.0

• Feature: BREAKING CHANGE TO LANGUAGE AND API: Add constructors keyword
  • This new keyword generates constructors from a union type
    • See the updated Haskell tutorial for more details
  • This means that constructors is now a reserved keyword
  • This adds a new Constructors constructor to the Expr type
  • See: https://github.com/dhall-lang/dhall-haskell/pull/199
• Feature: BREAKING CHANGE TO THE API: dhall-format preserves interpolation
  • This changes the TextLit constructor to represent an interpolated Text literal
  • See: https://github.com/dhall-lang/dhall-haskell/pull/220
• Feature: You can now define type synonyms using let
  • See: https://github.com/dhall-lang/dhall-haskell/pull/202
• Feature: Extend valid set of quoted labels
  • See: https://github.com/dhall-lang/dhall-lang/pull/65
  • See: https://github.com/dhall-lang/dhall-lang/pull/77
• Performance: Improve startup time when importing files, but not URLs
  • See: https://github.com/dhall-lang/dhall-haskell/pull/194
• Security: localhost/127.0.0.1 imports no longer count as local imports
  • Specifically: they cannot import environment variables or files
  • See: https://github.com/dhall-lang/dhall-haskell/pull/197
• Security: Fix potential type-checking bug
  • See: https://github.com/dhall-lang/dhall-haskell/pull/198
• Fix: BREAKING CHANGE TO API: Improve localization of error messages
  • This required fixing the type of normalize/shift/subst to preserve the first type parameter of Expr (i.e. they no longer delete Note constructors)
  • A new denote function was added for the explicit purpose of deleting Note constructors
  • See: https://github.com/dhall-lang/dhall-haskell/pull/218
• Expose MissingEnvironmentVariable exception type
  • See: https://github.com/dhall-lang/dhall-haskell/pull/196
• Add genericAuto
  • See: https://github.com/dhall-lang/dhall-haskell/pull/195
• Add inputWith
  • See: https://github.com/dhall-lang/dhall-haskell/pull/222
• AddloadWithContext
  • See: https://github.com/dhall-lang/dhall-haskell/pull/215
• Add pair/unit/string/list
  • See: https://github.com/dhall-lang/dhall-haskell/pull/227

1.8.2

• Add typeWithA for type-checking custom Embedded values
• Fix dhall{,-*} executables to ignore ambient locale and use UTF8
• Increase upper bound on tasty dependency

1.8.1

• dhall executable can now format output using --pretty
• Improved Unicode suppport on Windows

1.8.0

• BREAKING CHANGE TO LANGUAGE: Add support for import integrity checks
  • In practice, the likelihood of this breaking code in the wild is astronomically low
  • This would only break code of the form sha256:aaa...aaa (i.e. a variabled named sha256 with a type annotation for a type with a name 64 characters long drawn from the first 6 characters of the alphabet)
• BUG FIX: Fix parsing of single quotes in single-quoted strings
• BUG FIX: Fix superfluous parentheses introduced by dhall-format
• New dhall-hash executable
  • This goes hand-in-hand with the added support for integrity checks since the executable lets you compute the current hash of an import

1.7.0

• BREAKING CHANGE TO LANGUAGE: Update parser to match standardized grammar
  • Trailing commas and bars no longer supported for union and record literals
  • Paths no longer permit commas
  • URL grammar is now RFC-compliant
  • Environment variables can now be quoted to support full range of POSIX-compliant names
  • Text literals support full set of JSON escape sequences (such as \u2192)
• BREAKING CHANGE TO LANGUAGE: Single quoted strings strip leading newlines
• BUG FIX: Fixed type-checking infinite loops due to non-type-checked variables in context
• BUG FIX: Fixed type-checking bug due to missing context when type-checking certain expressions
• BUG FIX: Fixed type-checking bug due to off-by-one errors in name shadowing logic
• New dhall-format executable to automatically format code
• Performance optimizations to Natural/fold and List/fold
• Improved parsing performance (over 3x faster)
• Union literals can now specify the set value anywhere in the literal
  • i.e. < A : Integer | B = False | C : Text >
• New Inject instance for ()
• Several tutorial fixes and improvements

1.6.0

• BREAKING CHANGE TO THE API: Drop support for GHC 7.*
• BREAKING CHANGE TO THE API: Add support for customizing Dhall import
  • This is a breaking change because this changes the type of loadWith
• BREAKING CHANGE TO THE API: Add field to UnboundVariable error containing
• BUG FIX: Fix parsing single quotes in string literals the name of the unbound variable
• Add List/concatMap to the Prelude
• You can now derive Inject and Interpret for types with unlabeled fields
• Add new instances for Interpret:
  • []
  • (,)
• Add new instance for Inject
  • [], Data.Set.Set, Data.Sequence.Seq
  • (,)
  • Int, Word8, Word16, Word32, Word64
• Add Eq instance for Src

1.5.1

• Increase upper bound on vector and optparse-generic

1.5.0

• BREAKING CHANGE: Add list concatenation operator: (#)
  • This is a breaking change because it adds a new constructor to the Expr type which breaks exhaustive pattern matches
• BREAKING CHANGE: Add Interpret support for lazy Text
  • This is a breaking change because it renames text to strictText
• Add Interpret instance for decoding (a limited subset of) Dhall functions
• Dhall no longer requires Template Haskell to compile
  • This helps with cross-compilation
• Add rawInput utility for decoding a Haskell value from the Expr type
• Add loadWith/normalizeWith utilities for normalizing/importing modules with a custom context
• Export Type constructor

1.4.2

• Fix missing Prelude files in package archive uploaded to Hackage

1.4.1

• Fix missing tests/Tutorial.hs module in package archive uploaded to Hackage

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