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 Inf\s and NaN\s 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 macroexpand\ing 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