Julia v1.8 Release Notes

New language features

Module(:name, false, false) can be used to create a module that contains no names (it does not import Base or Core and does not contain a reference to itself). ([#40110, #42154])
@inline and @noinline annotations can be used within a function body to give an extra hint about the inlining cost to the compiler. ([#41312])
@inline and @noinline annotations can now be applied to a function callsite or block to enforce the involved function calls to be (or not to be) inlined. ([#41312])
The default behavior of observing @inbounds declarations is now an option via auto in --check-bounds=yes|no|auto ([#41551])
New function eachsplit(str) for iteratively performing split(str).
∀, ∃, and ∄ are now allowed as identifier characters ([#42314]).

Language changes

Newly created Task objects (@spawn, @async, etc.) now adopt the world-age for methods from their parent Task upon creation, instead of using the global latest world at start. This is done to enable inference to eventually optimize these calls. Places that wish for the old behavior may use Base.invokelatest. ([#41449])

Compiler/Runtime improvements

The LLVM-based compiler has been separated from the run-time library into a new library, libjulia-codegen. It is loaded by default, so normal usage should see no changes. In deployments that do not need the compiler (e.g. system images where all needed code is precompiled), this library (and its LLVM dependency) can simply be excluded ([#41936]).

Command-line option changes

Multi-threading changes

Build system changes

New library functions

hardlink(src, dst) can be used to create hard links. ([#41639])

New library features

@test_throws "some message" triggers_error() can now be used to check whether the displayed error text contains "some message" regardless of the specific exception type. Regular expressions, lists of strings, and matching functions are also supported. ([#41888])

Standard library changes

range accepts either stop or length as a sole keyword argument ([#39241])
The length function on certain ranges of certain specific element types no longer checks for integer overflow in most cases. The new function checked_length is now available, which will try to use checked arithmetic to error if the result may be wrapping. Or use a package such as SaferIntegers.jl when constructing the range. ([#40382])
TCP socket objects now expose closewrite functionality and support half-open mode usage ([#40783]).
Intersect returns a result with the eltype of the type-promoted eltypes of the two inputs ([#41769]).
Iterators.countfrom now accepts any type that defines +. ([#37747])

InteractiveUtils

A new macro @time_imports for reporting any time spent importing packages and their dependencies ([#41612])

Package Manager

LinearAlgebra

Markdown

Printf

Now uses textwidth for formatting %s and %c widths ([#41085]).

Profile

Profiling now records sample metadata including thread and task. Profile.print() has a new groupby kwarg that allows grouping by thread, task, or nested thread/task, task/thread, and threads and tasks kwargs to allow filtering. Further, percent utilization is now reported as a total or per-thread, based on whether the thread is idle or not at each sample. Profile.fetch() by default strips out the new metadata to ensure backwards compatibility with external profiling data consumers, but can be included with the include_meta kwarg. ([#41742])

Random

REPL

RadioMenu now supports optional keybindings to directly select options ([#41576]).
?(x, y followed by TAB displays all methods that can be called with arguments x, y, .... (The space at the beginning prevents entering help-mode.) MyModule.?(x, y limits the search to MyModule. TAB requires that at least one argument have a type more specific than Any; use SHIFT-TAB instead of TAB to allow any compatible methods.

SparseArrays

Dates

Downloads

Statistics

Sockets

Tar

Distributed

UUIDs

Mmap

DelimitedFiles

Logging

The standard log levels BelowMinLevel, Debug, Info, Warn, Error, and AboveMaxLevel are now exported from the Logging stdlib ([#40980]).

Deprecated or removed

External dependencies

Tooling Improvements