NEWS.rst

Unreleased

Other Breaking Changes

• Mangling rules have been overhauled, such that mangled names are always legal Python identifiers
• _ and - are now equivalent even as single-character names
  • The REPL history variable _ is now *1
• Non-shadow unary =, is, <, etc. now evaluate their argument instead of ignoring it. This change increases consistency a bit and makes accidental unary uses easier to notice.
• hy-repr uses registered functions instead of methods

New Features

• Python 3.7 is now supported
• Added mangle and unmangle as core functions
• defclass in Python 3 now supports specifying metaclasses and other keyword arguments
• Added a command-line option -E per CPython

Bug Fixes

• Fix (return) so it works correctly to exit a Python 2 generator
• Fixed a case where -> and ->> duplicated an argument
• Fixed bugs that caused defclass to drop statements or crash

Misc. Improvements

• hy-repr supports more standard types

0.14.0

Removals

• Python 3.3 is no longer supported
• def is gone; use setv instead
• apply is gone; use the new #* and #** syntax instead
• yield-from is no longer supported under Python 2
• Periods are no longer allowed in keywords
• Numeric literals can no longer begin with a comma or underscore
• Literal Infs and NaNs must now be capitalized like that

Other Breaking Changes

• Single-character "sharp macros" are now "tag macros", which can have longer names
• xi from hy.extra.anaphoric is now a tag macro #%
• eval is now a function instead of a special form

New Features

• The compiler now automatically promotes values to Hy model objects as necessary, so you can write (eval `(+ 1 ~n)) instead of (eval `(+ 1 ~(HyInteger n)))
• return has been implemented as a special form
• Added a form of string literal called "bracket strings" delimited by #[FOO[ and ]FOO], where FOO is customizable
• Added support for PEP 492 (async and await) with fn/a, defn/a, with/a, and for/a
• Added Python-style unpacking operators #* and #** (e.g., (f #* args #** kwargs))
• Added a macro comment
• Added EDN #_ syntax to discard the next term
• while loops may now contain an else clause, like for loops
• #% works on any expression and has a new &kwargs parameter %**
• Added a macro doc and a tag macro #doc
• get is available as a function
• ~@ (unquote-splice) form now accepts any false value as empty

Bug Fixes

• Relative imports (PEP 328) are now allowed
• Numeric literals are no longer parsed as symbols when followed by a dot and a symbol
• Hy now respects the environment variable PYTHONDONTWRITEBYTECODE
• String literals should no longer be interpreted as special forms or macros
• Tag macros (née sharp macros) whose names begin with ! are no longer mistaken for shebang lines
• Fixed a bug where REPL history wasn't saved if you quit the REPL with (quit) or (exit)
• exec now works under Python 2
• No TypeError from multi-arity defn returning values evaluating to None
• try forms are now possible in defmacro and deftag
• Multiple expressions are now allowed in try
• Fixed a crash when macroexpanding a macro with a named import
• Fixed a crash when with suppresses an exception. with now returns None in this case.
• Fixed a crash when --repl-output-fn raises an exception
• Fixed a crash when HyTypeError was raised with objects that had no source position
• assoc now evaluates its arguments only once each
• Multiple expressions are now allowed in the else clause of a for loop
• else clauses in for and while are recognized more reliably
• Statements in the condition of a while loop are repeated properly
• Argument destructuring no longer interferes with function docstrings
• Nullary yield-from is now a syntax error
• break and continue now raise an error when given arguments instead of silently ignoring them

Misc. Improvements

• read, read_str, and eval are exposed and documented as top-level functions in the hy module
• An experimental let macro has been added to hy.contrib.walk

0.13.1

Bug Fixes

• Changed setup.py to require astor 0.5, since 0.6 isn't backwards-compatible.

0.13.0

Language Changes

• Pythons 2.6, 3.0, 3.1, and 3.2 are no longer supported
• let has been removed. Python's scoping rules do not make a proper implementation of it possible. Use setv instead.
• lambda has been removed, but fn now does exactly what lambda did
• defreader has been renamed to defsharp; what were previously called "reader macros", which were never true reader macros, are now called "sharp macros"
• try now enforces the usual Python order for its elements (else must follow all excepts, and finally must come last). This is only a syntactic change; the elements were already run in Python order even when defined out of order.
• try now requires an except or finally clause, as in Python
• Importing or executing a Hy file automatically byte-compiles it, or loads a byte-compiled version if it exists and is up to date. This brings big speed boosts, even for one-liners, because Hy no longer needs to recompile its standard library for every startup.
• Added bytestring literals, which create bytes objects under Python 3 and str objects under Python 2
• Commas and underscores are allowed in numeric literals
• Many more operators (e.g., **, //, not, in) can be used as first-class functions
• The semantics of binary operators when applied to fewer or more than two arguments have been made more logical
• (** a b c d) is now equivalent to (** a (** b (** c d))), not (** (** (** a b) c) d)
• setv always returns None
• When a try form executes an else clause, the return value for the try form is taken from else instead of the try body. For example, (try 1 (except [ValueError] 2) (else 3)) returns 3.
• xor: If exactly one argument is true, return it
• hy.core.reserved is now hy.extra.reserved
• cond now supports single argument branches

Bug Fixes

• All shadowed operators have the same arities as real operators
• Shadowed comparison operators now use and instead of & for chained comparisons
• partition no longer prematurely exhausts input iterators
• read and read-str no longer raise an error when the input parses to a false value (e.g., the empty string)
• A yield inside of a with statement will properly suppress implicit returns
• setv no longer unnecessarily tries to get attributes
• loop no longer replaces string literals equal to "recur"
• The REPL now prints the correct value of do and try forms
• Fixed a crash when tokenizing a single quote followed by whitespace

Misc. Improvements

• New contrib module hy-repr
• Added a command-line option --repl-output-fn

0.12.1

Bug Fixes

• Allow installation without Git

0.12.0

This release brings some quite significant changes on the language and as a result very large portions of previously written Hy programs will require changes. At the same time, documentation and error messages were improved, hopefully making the language easier to use.

Language Changes

• New syntax for let, with and defclass
• defmacro will raise an error on &kwonly, &kwargs and &key arguments
• Keyword argument labels to functions are required to be strings
• slice replaced with cut to stop overloading the python built-in
• removed redundant throw, catch, progn, defun, lisp-if, lisp-if-not, filterfalse, true, false and nil
• global now takes multiple arguments
• Nonlocal keyword (Python 3 only)
• Set literals (#{1 2 3})
• Keyword-only arguments (Python 3 only)
• Setv can assign multiple variables at once
• Empty form allowed for setv, del and cond
• One-argument division, rationals and comparison operators (=, !=, <, >, <=, >=)
• partition form for chunking collection to n-sized tuples
• defn-alias and demacro-alias moved into hy.contrib.alias
• None is returned instead of the last form in --init--
• for and cond can take a multi-expression body
• Hex and octal support for integer literals
• Apply now mangles strings and keywords according to Hy mangling rules
• Variadic if
• defreader can use strings as macro names
• as-> macro added
• require syntax changed and now supports same features as import
• defmulti changed to work with dispatching function
• old defmulti renamed to defn
• Lazy sequences added to contrib
• defmacro! added for once-only evaluation for parameters
• comp, constantly, complement and juxt added
• keyword arguments allowed in method calls before the object

Bug Fixes

• Better error when for doesn't have body
• Better error detection with list comprehensions in Python 2.7
• Setting value to callable will raise an error
• defclass can have properties / methods with built-in names
• Better error messages on invalid macro arguments
• Better error messages with hy2py and hyc
• Cmdline error to string conversion.
• In python 3.3+, generator functions always return a value
• &rest can be used after &optional

Misc. Improvements

• Version information includes SHA1 of current commit
• Improved Python 3.5 support
• Allow specification of global table and module name for (eval ...)
• General documentation improvements
• Contrib.walk: Coerce non-list iterables into list form
• Flow macros (case and switch)
• ap-pipe and ap-compose macros
• #@ reader macro for with-decorator
• Type check eval parameters
• and and or short-circuit
• and and or accept zero or more arguments
• read-str for tokenizing a line
• botsbuildbots moved to contrib
• Trailing bangs on symbols are mangled
• xi forms (anonymous function literals)
• if form optimizations in some cases
• xor operator
• Overhauled macros to allow macros to ref the Compiler
• ap-if requires then branch
• Parameters for numeric operations (inc, dec, odd?, even?, etc.) aren't type checked
• import_file_to_globals added for use in emacs inferior lisp mode
• hy.core.reserved added for querying reserved words
• hy2py can use standard input instead of a file
• alias, curry, flow and meth removed from contrib
• contrib.anaphoric moved to hy.extra

Changes from 0.10.1

Language Changes

• new keyword-argument call syntax
• Function argument destructuring has been added.
• Macro expansion inside of class definitions is now supported.
• yield-from support for Python 2
• with-decorator can now be applied to classes.
• assert now accepts an optional assertion message.
• Comparison operators can now be used with map, filter, and reduce.
• new last function
• new drop-last function
• new lisp-if-not/lif-not macro
• new symbol? function
• butlast can now handle lazy sequences.
• Python 3.2 support has been dropped.
• Support for the @ matrix-multiplication operator (forthcoming in Python 3.5) has been added.

Bug Fixes

• Nested decorators now work correctly.
• Importing hy modules under Python >=3.3 has been fixed.
• Some bugs involving macro unquoting have been fixed.
• Misleading tracebacks when Hy programs raise IOError have been corrected.

Misc. Improvements

• attribute completion in REPL
• new -m command-line flag for running a module
• new -i command-line flag for running a file
• improved error messaging for attempted function definitions without argument lists
• Macro expansion error messages are no longer truncated.
• Error messaging when trying to bind to a non-list non-symbol in a let form has been improved.

Changes from 0.10.0

This release took some time (sorry, all my fault) but it's got a bunch of really nice features. We hope you enjoy hacking with Hy as much as we enjoy hacking on Hy.

In other news, we're Dockerized as an official library image! <https://registry.hub.docker.com/_/hylang/>

$ docker run -it --rm hylang hy 0.10.0 using CPython(default) 3.4.1 on Linux => ((lambda [] (print "Hello, World!"))) Hello, World!

• Hy Society

Language Changes

• Implement raise :from, Python 3 only.
• defmain macro
• name & keyword functions added to core
• (read) added to core
• shadow added to core
• New functions interleave interpose zip_longest added to core
• nth returns default value when out of bounds
• merge-with added
• doto macro added
• keyword? to find out keywords
• setv no longer allows "." in names

Internals

• Builtins reimplemented in terms of python stdlib
• gensyms (defmacro/g!) handles non-string types better

Tools

• Added hy2py to installed scripts

Misc. Fixes

• Symbols like true, false, none can't be assigned
• Set sys.argv default to [''] like Python does
• REPL displays the python version and platform at startup
• Dockerfile added for https://registry.hub.docker.com/_/hylang/

Contrib changes

• Fix ap-first and ap-last for failure conditions

Changes from 0.9.12

0.10.0 - the "oh man I'm late for PyCon" release

Thanks to theanalyst (Abhi) for getting the release notes together. You're the best! - Hy Society

Breaking Changes

We're calling this release 0.10 because we broke API. Sorry about that. We've removed kwapply in favor of using apply. Please be sure to upgrade all code to work with apply.

(apply function-call args kwargs) ; is the signature

Thanks

Major shoutout to Clinton Dreisbach for implementing loop/recur. As always, massive hugs to olasd for the constant reviews and for implementing HyCons cells. Thanks to @kenanb for redesigning the new Hy logo.

Many thanks to algernon for working on adderall, which helped push Hy further this cycle. Adderall is an implementation of miniKanren in Hy. If you're interested in using Adderall, check out hydiomatic, which prettifies Hy source using Adderall rules.

This release saw an increase of about 11 contributors for a point release, you guys rock!

-Hy Society

Language Changes

• for revamped again (Last time, we hope!), this time using a saner itertools.product when nesting
• lisp-if/lif added for the lisp-like everything is true if, giving seasoned lispers a better if check (0 is a value, etc)
• Reader Macros are macros now!
• yield-from is now a proper yield from on Python 3. It also now breaks on Python 2.x.
• Added if-not macro
• We finally have a lisp like cons cells
• Generator expressions, set & dict comprehensions are now supported
• (.) is a mini DSL for attribute access
• macroexpand & macroexpand-1 added to core
• disassemble added to core, which dumps the AST or equivalent python code
• coll? added to core to check for a collection
• identity function added to core

Misc. Fixes

• Lots of doc fixes. Reorganization as well as better docs on Hy internals
• Universal Wheel Support
• Pygments > 1.6 supports Hy now. All codeblocks in docs have been changed from clojure to hy
• Hy REPL supports invoking with --spy & -i options [reword]
• first and rest are functions and not macros anymore
• "clean" target added to Makefile
• hy2py supports a bunch of commandline options to show AST, source etc.
• Sub-object mangling: every identifier is split along the dots & mangled separately

Bug Fixes

• Empty MacroExpansions work as expected
• Python 3.4 port. Sorry this wasn't in a 3.4 release time, we forgot to do a release. Whoops.
• eg/lxml/parse-tumblr.hy works with Python 3
• hy2py works on Windows
• Fixed unicode encoding issue in REPL during unicode exceptions
• Fixed handling of comments at end of input (#382)

Contrib changes

• Curry module added to contrib
• Loop/recur module added which provides TCO at tail position
• defmulti has been added - check out more in the docs -- thanks to Foxboron for this one!
• Walk module for walking the Hy AST, features a macroexpand-all as well

Changes from Hy 0.9.11

tl;dr:

0.9.12 comes with some massive changes, We finally took the time to implement gensym, as well as a few other bits that help macro writing. Check the changelog for what exactly was added.

The biggest feature, Reader Macros, landed later in the cycle, but were big enough to warrant a release on its own. A huge thanks goes to Foxboron for implementing them and a massive hug goes out to olasd for providing ongoing reviews during the development.

Welcome to the new Hy contributors, Henrique Carvalho Alves, Kevin Zita and Kenan Bölükbaşı. Thanks for your work so far, folks!

Hope y'all enjoy the finest that 2013 has to offer, - Hy Society

• Special thanks goes to Willyfrog, Foxboron and theanalyst for writing 0.9.12's NEWS. Thanks, y'all! (PT)

Language Changes

• Translate foo? -> is_foo, for better Python interop. (PT)
• Reader Macros!
• Operators + and * now can work without arguments
• Define kwapply as a macro
• Added apply as a function
• Instant symbol generation with gensym
• Allow macros to return None
• Add a method for casting into byte string or unicode depending on python version
• flatten function added to language
• Add a method for casting into byte string or unicode depending on python version
• Added type coercing to the right integer for the platform

Misc. Fixes

• Added information about core team members
• Documentation fixed and extended
• Add astor to install_requires to fix hy --spy failing on hy 0.9.11.
• Convert stdout and stderr to UTF-8 properly in the run_cmd helper.
• Update requirements.txt and setup.py to use rply upstream.
• tryhy link added in documentation and README
• Command line options documented
• Adding support for coverage tests at coveralls.io
• Added info about tox, so people can use it prior to a PR
• Added the start of hacking rules
• Halting Problem removed from example as it was nonfree
• Fixed PyPI is now behind a CDN. The --use-mirrors option is deprecated.
• Badges for pypi version and downloads.

Syntax Fixes

• get allows multiple arguments

Bug Fixes

• OSX: Fixes for readline Repl problem which caused HyREPL not allowing 'b'
• Fix REPL completions on OSX
• Make HyObject.replace more resilient to prevent compiler breakage.

Contrib changes

• Anaphoric macros added to contrib
• Modified eg/twisted to follow the newer hy syntax
• Added (experimental) profile module

Changes from Hy 0.9.10

• Many thanks to Guillermo Vayá (Willyfrog) for preparing this release's release notes. Major shout-out. (PT)

Misc. Fixes

• Many many many documentation fixes
• Change virtualenv name to be hy
• Rewrite language.hy not to require hy.core.macros
• Rewrite the bootstrap macros in hy
• Cleanup the hy.macros module
• Add comments to the functions and reorder them
• Translation of meth from Python to Hy
• PY3 should really check for Python >= 3
• Add hy._compat module to unify all Python 2 and 3 compatibility codes.
• Import future.print_statement in hy code
• Coerce the contents of unquote-splice'd things to a list
• Various setup.py enhancements.
• PEP8 fixes
• Use setuptools.find_packages()
• Update PyPI classifiers
• Update website URL
• Install the argparse module in Python 2.6 and before
• Delete the duplicate rply in install_requires. With the PyPI version, tests are failed.
• Finally fixed access to hy.core.macros here. have to explicitly require them.

Language Changes

• Slightly cleaner version of drop-while, could use yield-from when ready
• Added many native core functions
• Add zero? predicate to check if an object is zero
• Macro if-python2 for compile-time choice between Python 2 and Python 3 code branches
• Added new travis make target to skip flake8 on pypy but run it on all others
• Add "spy mode" to REPL
• Add CL handling to hyc
• Add yield from via macro magic.
• Add some machinery to avoid importing hy in setup.py
• Add a rply-based parser and lexer
• Allow quoting lambda list keywords.
• Clarified rest / cdr, cleaned up require
• Make with return the last expression from its branch
• Fix yielding to not suck (#151)
• Make assoc accept multiple values, also added an even/odd check for checkargs
• Added ability to parse doc strings set in defclass declarations,
• Provide bin scripts for both Windows and *nix
• Removes setf in favor of setv

Changes from Hy 0.9.9

Stupid Fixes

• I forgot to include hy.core.language in the sdist. (PT)

Changes from Hy 0.9.8

Syntax Fixes

• Macros are now module-specific, and must be required when used. (KH)
• Added a few more string escapes to the compiler (Thomas Ballinger)
• Keywords are pseudo-callable again, to get the value out of a dict. (PT)
• Empty expression is now the same as an empty vector. (Guillermo Vaya)

Language Changes

• HyDicts (quoted dicts or internal HST repr) are now lists that compiled down to dicts by the Compiler later on. (ND)
• Macros can be constants as well. (KH)
• Add eval-when-compile and eval-and-compile (KH)
• Add break and continue to Hy (Morten Linderud)
• Core language libraries added. As example, I've included take and drop in this release. More to come (PT)
• Importing a broken module's behavior now matches Python's more closely. (Morten Linderud)

Misc. Fixes

• Ensure compiler errors are always "user friendly" (JD)
• Hy REPL quitter repr adjusted to match Hy syntax (Morten Linderud)
• Windows will no longer break due to missing readline (Ralph Moritz)

Changes from Hy 0.9.7

Syntax Fixes

• Quasi-quoting now exists long with quoting. Macros will also not expand things in quotes.
• kwapply now works with symbols as well as raw dicts. (ND)
• Try / Except will now return properly again. (PT)
• Bare-names sprinkled around the AST won't show up anymore (ND)

Language Changes

• Added a new (require) form, to import macros for that module (PT)
• Native macros exist and work now! (ND)
• (fn) and (lambda) have been merged (ND)
• New (defclass) builtin for class definitions (JD)
• Add unquote-splicing (ND)

Errata

• Paul was an idiot and marked the j-related bug as a JD fix, it was actually ND. My bad.

Changes from Hy 0.9.6

Syntax Fixes

• UTF-8 encoded hy symbols are now hy_... rather than __hy_..., it's silly to prefex them as such. (PT)
• j is no longer always interpreted as a complex number; we use it much more as a symbol. (ND)
• (decorate-with) has been moved to (with-decorate) (JD)
• New (unless) macro (JD)
• New (when) macro (JD)
• New (take) macro (@eigenhombre)
• New (drop) macro (@eigenhombre)
• import-from and import-as finally removed. (GN)
• Allow bodyless functions (JD)
• Allow variable without value in let declaration (JD)
• new (global) builtin (@eal)
• new lambda-list syntax for function defs, for var-arity, kwargs. (JK)

Language Changes

• HUGE rewrite of the compiler. Massive thanks go to olasd and jd for making this happen. This solves just an insane number of bugs. (ND, PT, JD)
• Eval no longer sucks with statements (ND)
• New magic binary flags / mis fixes with the hy interpreter (WKG + @eigenhombre)

Changes from Hy 0.9.5

Syntax Fixes

• .pyc generation routines now work on Python 3. (Vladimir Gorbunov)
• Allow empty (do) forms (JD)
• The else form is now supported in try statements. (JD)
• Allow (raise), which, like Python, will re-raise the last Exception. (JD)
• Strings, bools, symbols are now valid top-level entries. (Konrad Hinsen)
• UTF-8 strings will no longer get punycode encoded. (ND)
• bare (yield) is now valid. (PT)
• (try) now supports the (finally) form. (JD)
• Add in the missing operators and AugAssign operators. (JD)
• (foreach) now supports the (else) form. (JD)

WARNING: WARNING: READ ME: READ ME:

From here on out, we will only support "future division" as part of hy. This is actually quite a pain for us, but it's going to be quite an amazing feature.

This also normalizes behavior from Py 2 --> Py 3.

Thank you so much, Konrad Hinsen.

Language Changes

• (pass) has been removed from the language; it's a wart that comes from a need to create valid Python syntax without breaking the whitespace bits. (JD)
• We've moved to a new import style, (import-from) and (import-as) will be removed before 1.0. (GN)
• Prototypes for quoted forms (PT)
• Prototypes for eval (PT)
• Enhance tracebacks from language breakage coming from the compiler (JD)
• The REPL no longer bails out if the internals break (Konrad Hinsen)
• We now support float and complex numbers. (Konrad Hinsen)
• Keywords (such as :foo) are now valid and loved. (GN)

Changes from Hy 0.9.4

Syntax Fixes

• try now accepts else: (JD)

  (try BODY (except [] BODY) (else BODY))

Changes from Hy 0.9.4

Syntax Fixes

• Statements in the fn path early will not return anymore. (PT)
• Added "not" as the inline "not" operator. It's advised to still use "not-in" or "is-not" rather than nesting. (JD)
• let macro added (PT)
• Added "~" as the "invert" operator. (JD)

• catch now accepts a new format: (JD)

  (catch [] BODY) (catch [Exception] BODY) (catch [e Exception] BODY) (catch [e [Exception1 Exception2]] BODY)

• With's syntax was fixed to match the rest of the code. It's now: (PT)

  (with [name context-managed-fn] BODY) (with [context-managed-fn] BODY)

Language Changes

• Added and and or (GN)
• Added the tail threading macro (->>) (PT)
• UTF encoded symbols are allowed, but mangled. All Hy source is now presumed to be UTF-8. (JD + PT)
• Better builtin signature checking (JD)
• If hoisting (for things like printing the return of an if statement) have been added. '(print (if true true true))' (PT)

Documentation

• Initial documentation added to the source tree. (PT)

Changes from Hy 0.9.3

Syntax Fixes

• Nested (do) expressions no longer break Hy (PT)
• progn is now a valid alias for do (PT)
• defun is now a valid alias for defn (PT)
• Added two new escapes for and " (PT)

Language Changes

• Show a traceback when a compile-error bubbles up in the Hy REPL (PT)
• setf / setv added, the behavior of def may change in the future.
• print no longer breaks in Python 3.x (PT)
• Added list-comp list comprehensions. (PT)
• Function hoisting (for things like inline invocation of functions, e.g. '((fn [] (print "hi!")))' has been added. (PT)

• while form added. (ND)

  (while [CONDITIONAL] BODY)

Documentation

• Initial docs added. (WKG + CW)

Changes from Hy 0.9.2

General Enhancements

• hy.__main__ added, python -m hy will now allow a hy shim into existing Python scripts. (PT)

Language Changes

• import-as added to allow for importing modules. (Amrut Joshi)
• slice added to slice up arrays. (PT)
• with-as added to allow for context managed bits. (PT)
• % added to do Modulo. (PT)
• Tuples added with the '(, foo bar)' syntax. (PT)
• car / first added. (PT)
• cdr / rest added. (PT)
• hy --> .pyc compiler added. (PT)
• Completer added for the REPL Readline autocompletion. (PT)
• Merge the meth macros into hy.contrib. (PT)
• Changed __repr__ to match Hy source conventions. (PT)
• 2.6 support restored. (PT)

Changes from Hy 0.9.1

General Enhancements

• Hy REPL added. (PT)
• Doc templates added. (PT)

Language Changes

• Add pass (PT)
• Add yield (PT)
• Moved for to a macro, and move foreach to old for. (PT)
• Add the threading macro (->). (PT)
• Add "earmufs" in. (tenach)
• Add comments in (PT)

Changes from Hy 0.9.0

Language Changes

• Add throw (PT)
• Add try (PT)
• add catch (PT)

Changes from Hy 0.8.2

Notes

• Complete rewrite of old-hy. (PT)