julia/NEWS.md

Julia v1.14 Release Notes

New language features

• It is now possible to control which version of the Julia syntax will be used to parse a package by setting the compat.julia or syntax.julia_version key in Project.toml. This feature is similar to the notion of "editions" in other language ecosystems and will allow non-breaking evolution of Julia syntax in future versions. See the "Syntax Versioning" section in the code loading documentation ([#60018]).
• ᵅ (U+U+1D45), ᵋ (U+1D4B), ᶲ (U+1DB2), ˱ (U+02F1), ˲ (U+02F2), and ₔ (U+2094) can now also be used as operator suffixes, accessible as \^alpha, \^epsilon, \^ltphi, \_<, \_>, and \_schwa at the REPL ([#60285]).
• The @label macro can now create labeled blocks that can be exited early with break name [value]. Use @label name expr for named blocks or @label expr for anonymous blocks. Anonymous @label blocks participate in the default break scope: a plain break or break _ exits the innermost breakable scope, whether it is a loop or an @label block. The continue statement also supports labels with continue name to continue a labeled loop ([#60481]).
• typegroup blocks allow defining mutually recursive struct types that reference each other in their field types. All types in the group are resolved atomically at the end of the block ([#60569]).

Language changes

Compiler/Runtime improvements

• Type inference now refines field types through conditional checks and call signatures. For example, after if !isnothing(x.field), inference knows x.field is not nothing within the branch. Similarly, after a call like func(x.field) where func(::Int) is the only matching method, inference refines x.field to Int. This works for immutable struct fields and const fields of mutable structs. Mutable (non-const) fields are not supported due to the lack of per-object memory effect tracking; for those, the recommended pattern remains storing the field value in a local variable before the check (e.g. val = x.field; if !isnothing(val) ... end) ([#41199], [#47574]).
• Stack traces now show full method signatures with argument types for inlined frames, matching the display of non-inlined frames ([#53925]).

Command-line option changes

• -P <project> is now a shorthand for --project <project> ([#59867]).

Multi-threading changes

• New functions Threads.atomic_fence_heavy and Threads.atomic_fence_light provide support for asymmetric atomic fences, speeding up atomic synchronization where one side of the synchronization runs significantly less often than the other ([#60311]).
• Threads.@threads now supports array comprehensions with syntax like @threads [f(i) for i in 1:n], filtered comprehensions like @threads [f(i) for i in 1:n if condition(i)], typed comprehensions like @threads Float64[f(i) for i in 1:n], and multi-dimensional comprehensions like @threads [f(i,j) for i in 1:n, j in 1:m] (preserves dimensions). All scheduling options (:static, :dynamic, :greedy) are supported. Results preserve element order for :static and :dynamic scheduling; :greedy does not guarantee order. Non-indexable iterators are also supported. ([#59019])

Build system changes

New library functions

• tap(f) creates a function that calls f(x) for side effects and returns x. ([#61340]).
• Base.generating_output() has been made public (but not exported) to allow checking whether the current process is performing compilation for a pkgimage/sysimage ([#61224]).

New library features

• IOContext supports a new boolean hexunsigned option that allows for printing unsigned integers in decimal instead of hexadecimal ([#60267]).

• The StringView type wraps an AbstractVector{UInt8} and interprets it as a UTF-8 encoded string, superseding the StringViews.jl package ([#60526]).

• Package precompilation now supports running precompilation in a background task and has new interactive keyboard controls: c to cleanly cancel immediately, d to detach, i for a profile peek, v to toggle verbose mode showing elapsed time, CPU%, and memory usage, and ? for help. ([#60943]).

Standard library changes

• codepoint(c) now succeeds for overlong encodings. Base.ismalformed, Base.isoverlong, and Base.show_invalid are now public and documented (but not exported) ([#55152]).

JuliaSyntaxHighlighting

LinearAlgebra

Markdown

• Support "raw" or "inline" HTML inside Markdown data ([#60629], [#60632], [#60732])
• Support autolinks for email addresses (#60570)
• Many improvements and bugfixes for rendering Markdown lists in a terminal ([#55456], [#60519])
• Strikethrough text via ~strike~ or ~~through~~ is now supported by the Markdown parser. ([#60537])
• Many, many bug fixes and minor tweaks; overall behavior is now much closer to CommonMark ([#59977], [#60502])

Profile

Random

REPL

Test

• @test, @test_throws, and @test_broken now support a context keyword argument that provides additional information displayed on test failure. This is useful for debugging which specific case failed in parameterized tests ([#60501]).

• @test_throws, @test_warn, @test_nowarn, @test_logs, and @test_deprecated now support broken and skip keyword arguments for consistency with @test ([#60543]).

• New functions detect_closure_boxes and detect_closure_boxes_all find methods that allocate Core.Box in their lowered code, which can indicate performance issues from captured variables in closures.

Dates

• unix2datetime now accepts a keyword argument localtime=true to use the host system's local time zone instead of UTC ([#50296]).

InteractiveUtils

• less/@less and edit/@edit are now supported for documented variables ([#53539]).

Dates

External dependencies

Tooling Improvements

Deprecated or removed