0.8.1

Added

• Now warns when /futlib/... files are redundantly imported.

• futharki now prints warnings for files that are ":load"ed.

• The compiler now warns when entry points are declared with types
  that will become unnamed and opaque, and thus impossible to
  provide from the outside.

• Type variables invented by the type checker will now have a
  unicode subscript to distinguish them from type parameters
  originating in the source code.

• futhark-test and futhark-bench now support generating random
  test data.

• The library backends now generate proper names for arrays of
  opaque values.

• The parser now permits empty programs.

• Most transpositions are now a good bit faster, especially on
  NVIDIA GPUs.

Removed

• The <- symbol can no longer be used for in-place updates and
  record updates (deprecated in 0.7.3).

Changed

• Entry points that accept a single tuple-typed parameter are no
  longer silently rewritten to accept multiple parameters.

Fixed

• The :type command in futharki can now handle polymorphic
  expressions (#669).

• Fixed serious bug related to chaining record updates.

• Fixed type inference of record fields (#677).

• futharki no longer goes in an infinite loop if a for loop
  contains a negative upper bound.

• Overloaded number types can no longer carry aliases (#682).

0.7.4

Added

• Support type parameters for operator specs defined with val.

Fixed

• Fixed nasty defunctionalisation bug (#661).

• cabal/stack sdist works now.

0.7.3

Added

• Significant performance changes: there is now a constant extra
  compilation overhead (less than 200ms on most machines). However,
  the rest of the compiler is 30-40% faster (or more in some cases).

• A warning when ambiguously typed expressions are assigned a
  default (i32 or f64).

• In-place updates and record updates are now written with =
  instead of <-. The latter is deprecated and will be removed in
  the next major version (#650).

Fixed

• Polymorphic value bindings now work properly with module type
  ascription.

• The type checker no longer requires types used inside local
  functions to be unambiguous at the point where the local function
  is defined. They must still be unambiguous by the time the
  top-level function ends. This is similar to what other ML
  languages do.

• futhark-bench now writes "μs" instead of "us".

• Type inference for infix operators now works properly.

0.7.2

Added

• futhark-pkg now supports GitLab.

• futhark-tests --notty option now has a --no-terminal alias.
  --notty is deprecated, but still works.

• futhark-test now supports multiple entry points per test block.

• Functional record updates: r with f <- x.

Fixed

• Fix the -C option for futhark-test.

• Fixed incorrect type of reduce_by_index.

• Segmented reduce_by_index now uses much less memory.

0.7.1

Added

• C# backend by Mikkel Storgaard Knudsen (futhark-cs/futhark-csopencl).

• futhark-test and futhark-bench now take a --runner option.

• futharki now uses a new interpreter that directly interprets the
  source language, rather than operating on the desugared core
  language. In practice, this means that the interactive mode is
  better, but that interpretation is also much slower.

• A trace function that is semantically id, but makes futharki
  print out the value.

• A break function that is semantically id, but makes futharki
  stop and provide the opportunity to inspect variables in scope.

• A new SOAC, reduce_by_index, for expressing generalised
  reductions (sometimes called histograms). Designed and
  implemented by Sune Hellfritzsch.

Removed

• Most of futlib has been removed. Use external packages instead:

  • futlib/colour => https://github.com/athas/matte

  • futlib/complex => https://github.com/diku-dk/complex

  • futlib/date => https://github.com/diku-dk/date

  • futlib/fft => https://github.com/diku-dk/fft

  • futlib/linalg => https://github.com/diku-dk/fft

  • futlib/merge_sort, futlib/radix_sort => https://github.com/diku-dk/sorts

  • futlib/random => https://github.com/diku-dk/cpprandom

  • futlib/segmented => https://github.com/diku-dk/segmented

  • futlib/sobol => https://github.com/diku-dk/sobol

  • futlib/vector => https://github.com/athas/vector

  No replacement: futlib/mss, futlib/lss.

• zip6/zip7/zip8 and their unzip variants have been removed.
  If you build gigantic tuples, you're on your own.

• The >>> operator has been removed. Use an unsigned integer type
  if you want zero-extended right shifts.

Changed

• The largest/smallest values for numeric modules have been
  renamed highest/lowest.

Fixed

• Many small things.

0.6.3

Added

• Added a package manager: futhark-pkg. See also the
  documentation.

• Added log2 and log10 functions to f32 and f64.

• Module type refinement (with) now permits refining parametric
  types.

• Better error message when invalid values are passed to generated
  Python entry points.

• futhark-doc now ignores files whose doc comment is the word
  "ignore".

• copy now works on values of any type, not just arrays.

• Better type inference for array indexing.

Fixed

• Floating-point numbers are now correctly rounded to nearest even
  integer, even in exotic cases (#377).

• Fixed a nasty bug in the type checking of calls to consuming
  functions (#596).

0.6.2

Added

• Bounds checking errors now show the erroneous index and the size
  of the indexed array. Some other size-related errors also show
  more information, but it will be a while before they are all
  converted (and say something useful - it's not entirely
  straightforward).

• Opaque types now have significantly more readable names,
  especially if you add manual size annotations to the entry point
  definitions.

• Backticked infix operators can now be used in operator sections.

Fixed

• f64.e is no longer pi.

• Generated C library code will no longer abort() on application
  errors (#584).

• Fix file imports on Windows.

• futhark-c and futhark-opencl now generates thread-safe code (#586).

• Significantly better behaviour in OOM situations.

• Fixed an unsound interaction between in-place updates and
  parametric polymorphism (#589).

0.6.1

Added

• The real module type now specifies tan.

• futharki now supports entering declarations.

• futharki now supports a :type command (or :t for short).

• futhark-test and futhark-benchmark now support gzipped data
  files. They must have a .gz extension.

• Generated code now frees memory much earlier, which can help
  reduce the footprint.

• Compilers now accept a --safe flag to make them ignore unsafe.

• Module types may now define lifted abstract types, using the
  notation type ^t. These may be instantiated with functional
  types. A lifted abstract type has all the same restrictions as a
  lifted type parameter.

Removed

• The rearrange construct has been removed. Use transpose instead.

• futhark-mode.el has been moved to a separate
  repository.

• Removed |>> and <<|. Use >-> and <-< instead.

• The empty construct is no longer supported. Just use empty
  array literals.

Changed

• Imports of the basis library must now use an absolute path
  (e.g. /futlib/fft, not simply futlib/fft).

• /futlib/vec2 and /futlib/vec3 have been replaced by a new
  /futlib/vector file.

• Entry points generated by the C code backend are now prefixed with
  futhark_entry_ rather than just futhark_.

• zip and unzip are no longer language constructs, but library
  functions, and work only on two arrays and pairs, respectively.
  Use functions zipN/unzipN (for 2<=n<=8).

Fixed

• Better error message on EOF.

• Fixed handling of .. in import paths.

• Type errors (and other compiler feedback) will no longer contain
  internal names.

• futhark-test and friends can now cope with infinities and NaNs.
  Such values are printed and read as f32.nan, f32.inf,
  -f32.inf, and similarly for f32. In futhark-test, NaNs
  compare equal.

0.5.2

Added

• Array index section: (.[i]) is shorthand for (\x -> x[i]).
  Full slice syntax supported. (#559)

• New assert construct. (#464)

• futhark-mode.el now contains a definition for flycheck.

Fixed

• The index produced by futhark-doc now contains correct links.

• Windows linebreaks are now fully supported for test files (#558).

0.5.1

Added

• Entry points need no longer be syntactically first-order.

• Added overloaded numeric literals (#532). This means type
  suffixes are rarely required.

• Binary and unary operators may now be bound in patterns by
  enclosing them in parenthesis.

• futhark-doc now produces much nicer documentation. Markdown is
  now supported in documentation comments.

• /futlib/functional now has operators >-> and <-< for
  function composition. <<| are |>> are deprecated.

• /futlib/segmented now has a segmented_reduce.

• Scans and reductions can now be horizontally fused.

• futhark-bench now supports multiple entry points, just like
  futhark-test.

• ".." is now supported in include paths.

Removed

• The reshape construct has been removed. Use the
  flatten/unflatten functions instead.

• concat and rotate no longer support the @ notation. Use
  map nests instead.

• Removed -I/--library. These never worked with
  futhark-test/futhark-bench anyway.

Changed

• When defining a module type, a module of the same name is no
  longer defined (#538).

• The default keyword is no longer supported.

• /futlib/merge_sort and /futlib/radix_sort now define
  functions instead of modules.

Fixed

• Better type inference for rearrange and rotate.

• import path resolution is now much more robust.