Julia v1.7 Release Notes
New language features
(; a, b) = x
can now be used to destructure propertiesa
andb
ofx
. This syntax is equivalent toa = getproperty(x, :a); b = getproperty(x, :b)
(#39285).- Implicit multiplication by juxtaposition is now allowed for radical symbols (e.g.
x√y
andx∛y
) (#40173). - The short-circuiting operators
&&
and||
can now be dotted to participate in broadcast fusion as.&&
and.||
(#39594). ⫪
(U+2AEA,\Top
,\downvDash
) and⫫
(U+2AEB,\Bot
,\upvDash
,\indep
) may now be used as binary operators with comparison precedence (#39403).- Repeated semicolons can now be used inside array concatenation expressions to separate dimensions of an array, with the number of semicolons specifying the dimension. Just as a single semicolon in
[A; B]
has always described concatenating in the first dimension (vertically), now two semicolons[A;; B]
do so in the second dimension (horizontally), three semicolons;;;
in the third, and so on (#33697). - A backslash (
\
) before a newline inside a string literal now removes the newline while also respecting indentation. This can be used to split up long strings without newlines into multiple lines of code (#40753). - A backslash before a newline in command literals now always removes the newline, similar to standard string literals, whereas the result was not well-defined before (#40753).
Language changes
macroexpand
,@macroexpand
, and@macroexpand1
no longer wrap errors in aLoadError
. To reduce breakage,@test_throws
has been modified so that many affected tests will still pass (#38379).- The middle dot
·
(\cdotp
U+00b7) and the Greek interpunct·
(U+0387) are now treated as equivalent to the dot operator⋅
(\cdot
U+22c5) (#25157). - The minus sign
−
(\minus
U+2212) is now treated as equivalent to the hyphen-minus sign-
(U+002d) (#40948). - Destructuring will no longer mutate values on the left-hand side while iterating through values on the right-hand side. In the example of an array
x
,x[2], x[1] = x
will now swap the first and second elements ofx
, whereas it used to fill both entries withx[1]
becausex[2]
was mutated during the iteration ofx
(#40737). - The default random number generator has changed, so all random numbers will be different (even with the same seed) unless an explicit RNG object is used. See the section on the
Random
standard library below (#40546). Iterators.peel(itr)
now returnsnothing
whenitr
is empty instead of throwing aBoundsError
(#39569).- Multiple successive semicolons in an array expresion were previously ignored (e.g.,
[1 ;; 2] == [1 ; 2]
). This syntax is now used to separate dimensions (see New language features).
Compiler/Runtime improvements
Command-line option changes
- The Julia
--project
option and theJULIA_PROJECT
environment variable now support selecting shared environments like.julia/environments/myenv
the same way the package management console does: usejulia --project=@myenv
resp.export JULIA_PROJECT="@myenv"
(#40025).
Multi-threading changes
- Intrinsics for atomic pointer operations are now defined for certain byte sizes (#37847).
- Support for declaring and using individual fields of a mutable struct as atomic has been added; see the new
@atomic
macro (#37847). - If the
JULIA_NUM_THREADS
environment variable is set toauto
, then the number of threads will be set to the number of CPU threads (#38952). - Every
Task
object has a local random number generator state, providing reproducible (schedule-independent) execution of parallel simulation code by default. The default generator is also significantly faster in parallel than in previous versions (#40546). - Tasks can now migrate among threads when they are re-scheduled. Previously, a Task would always run on whichever thread executed it first (#40715).
Build system changes
New library functions
- Two argument methods
findmax(f, domain)
,argmax(f, domain)
and the correspondingmin
versions (#27613). isunordered(x)
returns true ifx
is a value that is normally unordered, such asNaN
ormissing
(#35316).- New
keepat!(vector, inds)
function which is the inplace equivalent ofvector[inds]
for a listinds
of integers (#36229). - Two arguments method
lock(f, lck)
now accepts aChannel
as the second argument (#39312). - New functor
Returns(value)
, which returnsvalue
for any arguments (#39794). - New macros
@something
and@coalesce
which are short-circuiting versions ofsomething
andcoalesce
, respectively (#40729). - New function
redirect_stdio
for redirectingstdin
,stdout
andstderr
(#37978). - New macro
Base.@invoke f(arg1::T1, arg2::T2; kwargs...)
provides an easier syntax to callinvoke(f, Tuple{T1,T2}, arg1, arg2; kwargs...)
(#38438). - New macro
Base.@invokelatest f(args...; kwargs...)
providing a convenient way to callBase.invokelatest(f, args...; kwargs...)
(#37971).
New library features
- The optional keyword argument
context
ofsprint
can now be set to a tuple of:key => value
pairs to specify multiple attributes (#39381). bytes2hex
andhex2bytes
are no longer limited to arguments of typeUnion{String,AbstractVector{UInt8}}
and now only require that they're iterable and have a length (#39710).stat(file)
now has a more detailed and user-friendlyshow
method (#39463).
Standard library changes
count
andfindall
now accept anAbstractChar
argument to search for a character in a string (#38675).- New methods
range(start, stop)
andrange(start, stop, length)
(#39228). range
now supportsstart
as an optional keyword argument (#38041).- Some operations on ranges will return a
StepRangeLen
instead of aStepRange
, to allow the resulting step to be zero. Previously,λ .* (1:9)
gave an error whenλ = 0
(#40320). islowercase
andisuppercase
are now compliant with the Unicode lower/uppercase categories (#38574).iseven
andisodd
functions now support non-Integer
numeric types (#38976).escape_string
now accepts a collection of characters via the keywordkeep
that are to be kept as they are (#38597).getindex
forNamedTuple
s now accepts a tuple of symbols in order to index multiple values (#38878).- Subtypes of
AbstractRange
now correctly follow the general array indexing behavior when indexed byBool
s, erroring for scalarBool
s and treating arrays (including ranges) ofBool
as logical indices (#31829). keys(::RegexMatch)
is now defined to return the capture's keys, by name if named, or by index if not (#37299).keys(::Generator)
is now defined to return the iterator's keys (#34678).RegexMatch
is now iterable, giving the captured substrings (#34355).lpad/rpad
are now defined in terms oftextwidth
(#39044).Test.@test
now acceptsbroken
andskip
boolean keyword arguments, which mimicTest.@test_broken
andTest.@test_skip
behavior, but allows skipping tests failing only under certain conditions. For example
can be replaced byif T == Float64 @test_broken isequal(complex(one(T)) / complex(T(Inf), T(-Inf)), complex(zero(T), zero(T))) else @test isequal(complex(one(T)) / complex(T(Inf), T(-Inf)), complex(zero(T), zero(T))) end
(#39322).@test isequal(complex(one(T)) / complex(T(Inf), T(-Inf)), complex(zero(T), zero(T))) broken=(T == Float64)
@lock
is now exported from Base (#39588).- The experimental function
Base.catch_stack()
has been renamed tocurrent_exceptions()
, exported from Base and given a more specific return type (#29901). - Some degree trigonometric functions,
sind
,cosd
,tand
,asind
,acosd
,asecd
,acscd
,acotd
,atand
now accept a square matrix (#39758). replace(::String)
now accepts multiple patterns, which will be applied left-to-right simultaneously, so only one pattern will be applied to any character, and the patterns will only be applied to the input text, not the replacements (#40484).
Package Manager
- If a package is
using
orimport
ed from thejulia>
prompt that isn't found but is available from a registry, apkg> add
prompt now offers to install the package into the current environment, precompile it, and continue to load it (#39026). - A new
Manifest.toml
format is now used that captures extensible metadata fields, including the julia version that generated the manifest. Old format manifests are still supported and will be maintained in their original format, unless the user runsPkg.upgrade_manifest()
to upgrade the format of the current environment's manifest without re-resolving (#40765). pkg> precompile
will now precompile new versions of packages that are already loaded, rather than postponing to the next session (the?
-marked dependencies) (#40345).pkg> rm
,pin
, andfree
now accept the--all
argument to call the action on all packages.- Registries downloaded from the Pkg Server (not git) are no longer uncompressed into files but instead read directly from the compressed tarball into memory. This improves performance on filesystems which do not handle a large number of files well. To turn this feature off, set the environment variable
JULIA_PKG_UNPACK_REGISTRY=true
. - It is now possible to use an external
git
executable instead of the default libgit2 library for the downloads that happen via the Git protocol by setting the environment variableJULIA_PKG_USE_CLI_GIT=true
. - Registries downloaded from the Pkg Server (not git) is now assumed to be immutable. Manual changes to their files might not be picked up by a running Pkg session.
- Adding packages by directory name in the REPL mode now requires prepending
./
to the name if the package is in the current directory; e.g.add ./Package
is required instead ofadd Package
. This is to avoid confusion between the package namePackage
and the local directoryPackage
. - The
mode
keyword forPackageSpec
has been removed.
LinearAlgebra
- Use Libblastrampoline to pick a BLAS and LAPACK at runtime. By default it forwards to OpenBLAS in the Julia distribution. The forwarding mechanism can be used by packages to replace the BLAS and LAPACK with user preferences (#39455).
- On aarch64, OpenBLAS now uses an ILP64 BLAS like all other 64-bit platforms (#39436).
- OpenBLAS is updated to 0.3.13 (#39216).
- SuiteSparse is updated to 5.8.1 (#39455).
- The shape of an
UpperHessenberg
matrix is preserved under certain arithmetic operations, e.g. when multiplying or dividing by anUpperTriangular
matrix (#40039). - Real quasitriangular Schur factorizations
S
can now be efficiently converted to complex upper-triangular form withSchur{Complex}(S)
(#40573). cis(A)
now supports matrix arguments (#40194).dot
now supportsUniformScaling
withAbstractMatrix
(#40250).qr[!]
andlu[!]
now supportLinearAlgebra.PivotingStrategy
(singleton type) values as their optionalpivot
argument: defaults areqr(A, NoPivot())
(vs.qr(A, ColumnNorm())
for pivoting) andlu(A, RowMaximum())
(vs.lu(A, NoPivot())
without pivoting); the formerVal{true/false}
-based calls are deprecated (#40623).det(M::AbstractMatrix{BigInt})
now callsdet_bareiss(M)
, which uses the Bareiss algorithm to calculate precise values (#40868).
Markdown
Printf
Random
- The default random number generator has been changed from Mersenne Twister to Xoshiro256++. The new generator has smaller state, better performance, and superior statistical properties. This generator is the one used for reproducible Task-local randomness (#40546).
REPL
- Long strings are now elided using the syntax
"head" ⋯ 12345 bytes ⋯ "tail"
when displayed in the REPL (#40736). - Pasting repl examples into the repl (prompt pasting) now supports all repl modes (
julia
,pkg
,shell
,help?
) and switches mode automatically (#40604). help?>
for modules without docstrings now returns a list of exported names and prints the contents of an associatedREADME.md
if found (#39093).
SparseArrays
- new
sizehint!(::SparseMatrixCSC, ::Integer)
method (#30676). cholesky()
now fully preserves the user-specified permutation (#40560).issparse
now applies consistently to all wrapper arrays, including nested, by checkingissparse
on the wrapped parent array (#37644).
Dates
- The
Dates.periods
function can be used to get theVector
ofPeriod
s that comprise aCompoundPeriod
(#39169).
Downloads
- If a cookie header is set in a redirected request, the cookie will now be sent in following requests (https://github.com/JuliaLang/Downloads.jl/pull/98).
- If a
~/.netrc
file exists, it is used to get passwords for authenticated websites (https://github.com/JuliaLang/Downloads.jl/pull/98). - Server Name Indication is now sent with all TLS connections, even when the server's identity is not verified (see NetworkOptions; https://github.com/JuliaLang/Downloads.jl/pull/114).
- When verifying TLS connections on Windows, if the certificate revocation server cannot be reached, the connection is allowed; this matches what other applications do and how revocation is performed on macOS (https://github.com/JuliaLang/Downloads.jl/pull/115).
- There is now a 30-second connection timeout and a 20-second timeout if no data is sent; in combination, this guarantees that connections must make some progress or they will timeout in under a minute (https://github.com/JuliaLang/Downloads.jl/pull/126).
Statistics
Sockets
Tar
Tar.extract
now ignores the exact permission mode in a tarball and normalizes modes in the same way thatTar.create
does, which is, in turn the same way thatgit
normalizes them (https://github.com/JuliaIO/Tar.jl/pull/99).- Functions that consume tarballs now handle hard links: the link target must be a previously seen file;
Tar.list
lists the entry with:hardlink
type and.link
field giving the path to the target; other functions —Tar.extract
,Tar.rewrite
,Tar.tree_hash
— treat a hard link as a copy of the target file (https://github.com/JuliaIO/Tar.jl/pull/102). - The standard format generated by
Tar.create
andTar.rewrite
now includes entries for non-empty directories; this shouldn't be neccessary, but some tools that consume tarballs (including docker) are confused by the absence of these directory entries (https://github.com/JuliaIO/Tar.jl/pull/106). Tar
now accepts tarballs with leading spaces in octal integer header fields: this is technically not a valid format according to the POSIX spec, but old Solaristar
commands produced tarballs like this so this format does occur in the wild, and it seems harmless to accept it (https://github.com/JuliaIO/Tar.jl/pull/116).Tar.extract
now takes aset_permissions
keyword argument, which defaults totrue
; iffalse
is passed instead, the permissions of extracted files are not modified on extraction (https://github.com/JuliaIO/Tar.jl/pull/113).
Distributed
UUIDs
Mmap
mmap
is now exported (#39816).
DelimitedFiles
readdlm
now defaults touse_mmap=false
on all OSes for consistent reliability in abnormal filesystem situations (#40415).