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).

  • (U+U+1D45), (U+1D4B), (U+1DB2), ˱ (U+02F1), ˲ (U+02F2), and (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).

Command-line option changes

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

  • 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).

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

Dates

External dependencies

Tooling Improvements

Deprecated or removed