NEWS.md

Julia v0.2.0 Release Notes

The 0.2 release brings improvements to many areas of Julia. Among the most visible changes are support for 64-bit Windows, keyword arguments to functions, immutable types, a redesigned and polished package manager, a multimedia interface supporting usage of Julia in IPython, a built-in profiler, and major improvements to Julia's linear algebra, I/O, and parallel capabilities. These are accompanied by many other changes adding new features, enhancing the library's consistency, improving performance, increasing test coverage, easing installation, and expanding the documentation. While not part of Julia proper, the package ecosystem has also grown and matured considerably since the 0.1 release. See below for more information about the long list of changes that improve Julia's usability and performance.

New language features

• Keyword & optional function arguments (#485, #1817).

• Immutable types (#13).

• Triple-quoted string literals (#70).

• New infix operator in (e.g. x in S), and corresponding function in(x,S), replacing contains(S,x) function (#2703).

• New variable bindings on each for loop and comprehension iteration (#1571). For example, before this change:

  julia> map(f->f(), { ()->i for i=1:3 })
  3-element Any Array:
   3
   3
   3
  

  and after:

  julia> map(f->f(), { ()->i for i=1:3 })
  3-element Any Array:
   1
   2
   3
  

• Explicit relative importing (#2375).

• Methods can be added to functions in other modules using dot syntax, as in Foo.bar(x) = 0.

• A semicolon is now allowed after an import or using statement (#4130).

• In an interactive session (REPL), you can use ;cmd to run cmd via an interactive shell. For example:

  julia> ;ls
  CONTRIBUTING.md  Makefile           VERSION      deps/      julia@  ui/
  DISTRIBUTING.md  NEWS.md            Windows.inc  doc/       src/    usr/
  LICENSE.md       README.md          base/        etc/       test/
  Make.inc         README.windows.md  contrib/     examples/  tmp/
  

New library functions

• Sampling profiler (#2597).

• Functions for examining stages of the compiler's output: code_lowered, code_typed, code_llvm, and code_native.

• Multimedia I/O API (display, writemime, etcetera) (#3932).

• MPFR-based BigFloat (#2814), and many new BigFloat operations.

• New half-precision IEEE floating-point type, Float16 (#3467).

• Support for setting floating-point rounding modes (#3149).

• methodswith shows all methods with an argument of specific type.

• mapslices provides a general way to perform operations on slices of arrays (#2204).

• repeat function for constructing Arrays with repeated elements ([#3605]).

• Collections.PriorityQueue type and Collections.heap functions (#2920).

• quadgk 1d-integration routine (#3140).

• erfinv and erfcinv functions (#2987).

• varm, stdm (#2265).

• digamma, invdigamma, trigamma and polygamma for calculating derivatives of gamma function ([#3233]).

• logdet (#3070).

• Names for C-compatible types: Cchar, Clong, etc. (#2370).

• cglobal to access global variables (#1815).

• unsafe_pointer_to_objref (#2468) and pointer_from_objref (#2515).

• readandwrite for external processes.

• I/O functions readbytes and readbytes! (#3878).

• flush_cstdio function (#3949).

• ClusterManager makes it possible to support different types of compute clusters (#3649, #4014).

• rmprocs for removing processors from a parallel computing session. The system can also tolerate to some extent processors that die unexpectedly (#3050).

• interrupt for interrupting worker processes (#3819).

• timedwait does a polled wait for an event till a specified timeout.

• Condition type with wait and notify functions for Task synchronization.

• versioninfo provides detailed version information, especially useful when reporting and diagnosing bugs.

• detach for running child processes in a separate process group.

• setenv for passing environment variables to child processes.

• ifelse eagerly-evaluated conditional function, especially useful for vectorized conditionals.

Library improvements

• isequal now returns false for numbers of different types. This makes it much easier to define hashing for new numeric types. Uses of Dict with numeric keys might need to change to account for this increased strictness.

• A redesigned and rewritten Pkg system is much more robust in case of problems. The basic interface to adding and removing package requirements remains the same, but great deal of additional functionality for developing packages in-place was added. See the new packages chapter in the manual for further details.

• Sorting API updates (#3665) – see sorting functions.

• The delete!(d::Dict, key) function has been split into separate pop! and delete! functions (#3439). pop!(d,key) removes key from d and returns the value that was associated with it; it throws an exception if d does not contain key. delete!(d,key) removes key from d and succeeds regardless of whether d contained key or not, returning d itself in either case.

• Linear-algebra factorization routines (lu, chol, etc.) now return Factorization objects (and lud, chold, etc. are deprecated; #2212).

• A number of improvements to sparse matrix capabilities and sparse linear algebra.

• More linear algebra fixes and eigensolver hooks for SymTridiagonal, Tridiagonal and Bidiagonal matrix types (#2606, #2608, #2609, #2611, #2678, #2713, #2720, #2725).

• Change integer_valued, real_valued, and so on to isinteger, isreal, and so on, and semantics of the later are now value-based rather than type-based, unlike MATLAB/Octave (#3071). isbool and iscomplex are eliminated in favor of a general iseltype function.

• Transitive comparison of floats with rationals (#3102).

• Fast prime generation with primes and fast primality testing with isprime.

• sum and cumsum now use pairwise summation for better accuracy (#4039).

• Dot operators (.+, .* etc.) now broadcast singleton dimensions of array arguments. This behavior can be applied to any function using broadcast(f, ...).

• combinations, permutations, and partitions now return iterators instead of a task, and integer_partitions has been renamed to partitions (#3989, #4055).

• isreadable/iswritable methods added for more IO types (#3872).

• Much faster and improved readdlm and writedlm (#3350, #3468, #3483).

• Faster matchall (#3719), and various string and regex improvements.

• Documentation of advanced linear algebra features (#2807).

• Support optional RTLD flags in dlopen (#2380).

• pmap now works with any iterable collection.

• Options in pmap for retrying or ignoring failed tasks.

• New sinpi(x) and cospi(x) functions to compute sine and cosine of pi*x more accurately (#4112).

• New implementations of elementary complex functions sqrt, log, asin, acos, atan, tanh, asinh, acosh, atanh with correct branch cuts (#2891).

• Improved behavior of SubArray (#4412, #4284, #4044, #3697, #3790, #3148, #2844, #2644 and various other fixes).

• New convenience functions in graphics API.

• Improved backtraces on Windows and OS X.

Deprecated or removed

• Methods of min and max that do reductions were renamed to minimum and maximum. min(x) is now minimum(x), and min(x,(),dim) is now minimum(x,dim). (#4235)

• ComplexPair was renamed to Complex and made immutable, and Complex128 and so on are now aliases to the new Complex type.

• ! was added to the name of many mutating functions, e.g., push was renamed push! (#907).

• ref renamed to getindex, and assign to setindex! (#1484).

• writeable renamed to writable (#3874).

• logb and ilogb renamed to exponent (#2516).

• quote_string became a method of repr.

• safe_char, check_ascii, and check_utf8 replaced by is_valid_char, is_valid_ascii, and is_valid_utf8, respectively.

• each_line, each_match, begins_with, ends_with, parse_float, parse_int, and seek_end replaced by: eachline, eachmatch, and so on (_ was removed) (#1539).

• parse_bin(s) replaced by parseint(s,2); parse_oct(s) replaced by parseint(s,8); parse_hex(s) replaced by parseint(s,16).

• findn_nzs replaced by findnz (#1539).

• DivideByZeroError replaced by DivideError.

• addprocs_ssh, addprocs_ssh_tunnel, and addprocs_local replaced by addprocs (with keyword options).

• remote_call, remote_call_fetch, and remote_call_wait replaced by remotecall, remotecall_fetch, and remotecall_wait.

• has replaced by in for sets and by haskey for dictionaries.

• diagmm and diagmm! replaced by scale and scale! (#2916).

• unsafe_ref and unsafe_assign replaced by unsafe_load and unsafe_store!.

• add_each! and del_each! replaced by union! and setdiff!.

• isdenormal renamed to issubnormal (#3105).

• expr replaced by direct call to Expr constructor.

• |, &, $, -, and ~ for sets replaced by union, intersect, symdiff, setdiff, and complement (#3272).

• square function removed.

• pascal function removed.

• add and add! for Set replaced by push!.

• ls function deprecated in favor of readdir or ;ls in the REPL.

• start_timer now expects arguments in units of seconds, not milliseconds.

• Shell redirection operators |, >, and < eliminated in favor of a new operator |> (#3523).

• amap is deprecated in favor of new mapslices functionality.

• The Reverse iterator was removed since it did not work in many cases.

• The gcd function now returns a non-negative value regardless of the argument signs, and various other sign problems with invmod, lcm, gcdx, and powermod were fixed ([#4811]).

Miscellaneous changes

• julia-release-* executables renamed to julia-*, and libjulia-release renamed to libjulia (#4177).

• Packages will now be installed in .julia/vX.Y, where X.Y is the current Julia version.

Bugfixes and performance updates

Too numerous to mention.