v0.6.0

[0.6.0] - 2026-07-18

Changed

• BREAKING: {} is now always the empty set; the empty map is {:}. {} in
  a map-typed position no longer resolves to an empty map - it is a compile error
  that points at {:}, and the reverse ({:} where a set is expected) reports
  the same way. Migration is mechanical: map<K,V> m = {} becomes
  map<K,V> m = {:}. Set literals are unaffected. This supersedes the contextual
  {} resolution added in 0.5.0: Type::EmptySetOrMap and its span-keyed
  override map are removed, so the set/map ambiguity no longer reaches semantics
  or codegen. Closes #266.
• Valgrind and benchmark PR reports render as charts: the PR comment now shows
  a leak split pie, per-phase median bars, and an exact-numbers table instead of
  raw log dumps; raw logs stay in the collapsed details. All rendered values are
  whitelisted or numeric-validated since Build artifacts are fork-controlled (#267).
• CI fails on orphaned insta snapshots: deleting or renaming a test_scripts/
  file no longer strands its snapshot as phantom coverage; 52 accumulated orphans
  were deleted and the gate keeps new ones out (#271).

Added

• if expressions support else if chains and multi-line branches: an if
  used in expression position (auto g = if c { a } else { b }) previously
  accepted only a single-line, single-else form. It now accepts else if
  chains and branches whose value spans multiple lines, matching the statement
  form. Each branch is still a single value expression; a chain parses as a
  nested if-expression, so no new AST shape, semantics, or codegen was needed
  (branch type-agreement checks still apply). Closes #281.

Fixed

• ++/-- on a captured variable inside a closure: a standalone count++
  in a lambda body was rejected by the parser's no-postfix-in-expression guard as
  if it were nested in an expression, even though a bare x++ statement is valid
  anywhere. The guard now only rejects a postfix ++/-- genuinely nested inside
  a larger expression (e.g. a + y++), which stays disallowed by design. Codegen
  already handled the captured increment. Closes #280.
• Match-arm bindings no longer leak past the match: a match-arm pattern
  binding (e.g. n in n if n % 2 == 0) or an arm-body local stayed in the
  codegen variable table after the match, so a later declaration reusing the
  name (auto n = 3) reused the arm-local slot. That slot's alloca lived in a
  conditional arm block that did not dominate the later store, so the program
  failed with invalid LLVM IR ("instruction does not dominate all uses"). Match
  bindings are now scoped to the match; a subsequent same-named declaration gets
  a fresh slot. Reassignment of an outer variable inside an arm still persists.
• Recursive and mutually-recursive functions in imported modules: a call to
  a function in the same imported module (including a recursive self-call) was
  emitted against the bare, unmangled LLVM name and failed with "Undefined
  function: ". The current-function name recorded while generating an
  imported module body is now the mangled module!name, so same-module calls
  resolve through the existing nested-name logic. A related failure - a
  non-identifier argument such as n - 1 in a recursive call reporting
  "Undefined variable" - is fixed by resolving argument types through the
  codegen fallback tables when the analyzer's function scope is unavailable.
• Cross-module constant access: reading a const defined in an imported
  module through the module namespace (math.PI) now compiles. Previously only
  stdlib module constants resolved; a user module constant fell through to
  "Field access not supported for expression type Identifier". The module's own
  code could already read the constant; only the namespaced access from an
  importing file was missing. A same-named local in the caller does not shadow
  the module constant. (Known limitation: two imported modules that declare the
  same-named constant collide under the flat global-name model, tracked in #279.)
• Compound assignment and increment on class fields: self.value++,
  self.value += n, and the obj.field forms now compile. Previously ++/--
  on a field failed codegen with "Cannot increment on non-identifier" and +=/-=
  with "Assignment to non-identifier/deref not implemented", even though semantic
  analysis accepted them. Both now route through the same field-store path as a
  plain obj.field = ... assignment, so reference counting and where-clause field
  invariants still apply.
• auto now rejects nested empty collections consistently: auto x = {1: []}
  and auto x = [[]] previously passed semantic analysis with an unresolved
  element type, while the set/map equivalents were caught. All empty collection
  kinds are now guarded.
• Empty-collection inference help text: suggested {} for every collection,
  including lists (list<int> myVar = {}). Each kind now shows its own literal
  syntax ([], {:}, {}).

Security

• Lockfile bump for the postgres stack: postgres-protocol 0.6.11 -> 0.6.12
  (RUSTSEC-2026-0179 SCRAM CPU-exhaustion DoS, RUSTSEC-2026-0180 hstore decode
  panic) and tokio-postgres 0.7.17 -> 0.7.18 (RUSTSEC-2026-0178 short DataRow
  panic); postgres-types 0.2.13 -> 0.2.14 moved with the stack (no advisory of
  its own). Transitive via mux-runtime's postgres dependency; cargo audit is
  clean again.

v0.5.0

[0.5.0] - 2026-07-13

This release completes the split of the former monorepo into independent repos.
mux-compiler is now the canonical "Mux version" and resolves/reports the runtime
version independently; the runtime, website, playground API, and syntax
highlighting each live in and version from their own repos. Requires
mux-runtime 0.5.0.

Added

• Where-clause constraints: where { expr, ... } attaches runtime constraints to
  functions, methods, lambdas, interface methods, enum variants, fields, and classes.
  Provable violations are compile errors (zero-false-positive); the runtime panic is the
  fallback. Closes #224 (#235).
• Reject provable runtime panics at compile time: The compiler now turns provable
  runtime panics into compile-time errors, using the zero-false-positive const-fold path.
  Closes #238.
• cargo bench harness (criterion): Compiler-phase benchmarks (lex, parse, semantics,
  codegen, end-to-end pipeline) run over the whole compiling test_scripts corpus, plus
  end-to-end execution throughput benchmarks for a curated set of compiled workloads. A
  stdlib-only scripts/bench-report.py aggregates the per-file medians into a box-and-whisker
  per phase. Benchmarks are local/manual and a non-blocking CI report, never a merge gate.
  Closes #247.
• Valgrind memory checking: CI now runs compiled programs and the compiler under Valgrind
  (Memcheck), gating on definite/indirect leaks and memory errors with checked-in suppressions
  for benign third-party noise. Closes #246.
• Range-literal syntax diagnostic: A targeted diagnostic for a digit followed by ..
  (range-literal syntax) replaces the previous generic parse error. Closes #245.
• Independent runtime version resolution: The compiler resolves and reports the runtime
  version independently of its own version, so mux --version reports both (e.g.
  mux 0.5.0 (runtime 0.5.0)).

Changed

• Repo split from the monorepo: Extracted the runtime, website, playground API, and syntax
  highlighting into their own repos; removed the root VERSION file and sync-version tooling;
  scoped the SonarCloud analysis to the compiler; and rebound the project identity to
  muxlang/mux-compiler. Internals documentation now points at muxlang/mux-context.
• CLI polish: Colored diagnostics, styled help output, doctor glyphs, a version banner, and
  a compile spinner. Closes #249.
• Runtime panic documentation and behavior updated (#225, #230).
• Removed ad-hoc perf tooling: Deleted scripts/measure-baseline.sh,
  scripts/check-timings.py, and the orphaned infra/ci/baselines/*.json timing budgets, and
  stripped the unused --timings-file plumbing from run-checks.sh / integration-checks.sh.
  Also removed the unused cargo-fuzz setup under mux-compiler/fuzz/.
• Slimmed the README to a real README and pointed internals at muxlang/mux-context.

Fixed

• mux build / mux run now fail on link errors: A failed clang link previously printed
  the error but exited 0 (build reported success with no executable; run could fall through
  and execute a stale binary from a prior build). report_clang_output_or_exit now exits
  non-zero as its name implies.
• Reference-counting correctness: Reference-count cleanup for owned temporaries plus
  init/copy correctness fixes (#253); closures are now allocated with a reference-count header.
  Closes #250 (#252).
• Collection read-path performance and correctness: Fixed O(n^2) indexed reads,
  runtime-cache staleness, and Python-style negative indexing on collection reads
  (#256, #258, #259, #260).
• match usable as a statement: match now works as a statement and the guarded-arm
  exhaustiveness hole is closed (#233, #234, #243) (#242).
• Trailing commas: Allow trailing commas before newline-closed collection delimiters (#244).
• Enum codegen: Load enums from boxed pointers correctly in codegen (#237).
• Release checksum verification: Verify release checksums by hash, not path.

Security

• cmov 0.5.3 -> 0.5.4: Bumped to fix GHSA-3rjw-m598-pq24 (#254).

v0.4.1

[0.4.1] - 2026-06-27

Fixed

• Windows CI linker failure (xml2.lib): The conda-forge libxml2 packages do not install any .lib import library into Library/lib/, causing LNK1181: cannot open input file 'xml2.lib' on windows-latest runners. Fixed by adding a dedicated step after MSVC toolchain setup that generates xml2.lib from the installed libxml2*.dll using dumpbin /exports and lib.exe.

v0.4.0

[0.4.0] - 2026-06-26

Added

• Mux AI documentation assistant: In-docs chat widget powered by a Cloudflare Worker (RAG over mux-website/docs/ via Vectorize + Llama 3.3 70B). Answers Mux questions with citations, explains compiler errors, and rejects off-topic queries. Includes tools/docs-indexer/ for re-indexing and tools/retrieval-test/ eval harness (8/8 retrieval, 19/19 error-explainer). Full runbook in workers/mux-ai/README.md.
• DSA stdlib expanded: Added algorithm.mux (generic graph algorithms: topological sort, cycle detection, DFS, BFS), graph.mux (adjacency-list directed graph), bintree.mux (binary tree with inorder/preorder/postorder traversals), heap.mux (min/max heap), queue.mux (FIFO), stack.mux (LIFO), and collection.mux (base Collection interface). Closes #203.
• to_char() conversion method: Implemented string.to_char() -> result<char, string> and int.to_char() -> char (Unicode code-point to char). Closes #207.
• to_list() on set and map: set<T>.to_list() and map<K,V>.to_list() now registered and callable. Closes #209.

Changed

• LLVM upgraded from 17 to 22: Migrated inkwell dependency and all CI/build tooling to LLVM 22, which is more broadly available and actively maintained. Closes #215.
• Dead code elimination: Unused symbols (variables, classes, enums, functions, generics) are no longer emitted to LLVM IR, reducing binary size and intermediate output. Closes #200.
• Minimal end-user installation: End-user installs now ship only the compiler binary and runtime; development tooling (LLVM, clang, analysis tools) is separated into the dev setup path. Closes #193.
• God Object refactor: Broke down oversized structs/impls in the compiler (semantic analyzer, codegen context) into smaller focused components. Closes #194.
• Improved error messages for collection types: Set and map type errors now display set<T> and map<K,V> instead of raw brace-syntax ({char}, {string: int}). Closes #210.
• Improved error for .new() on built-in collections: Calling list.new(), map.new(), or set.new() now emits a helpful diagnostic suggesting [] or {} literal syntax instead of a generic undefined-type error. Closes #204.
• SonarQube and Greptile cleanups: Addressed code quality findings across multiple passes: god-object decomposition, vulnerability dependency updates, and ESLint/security-hotspot fixes in the website.

Fixed

• void functions require explicit return: Functions declared returns void without a return statement now produce a compile-time error instead of silently compiling. Closes #211.
• Map {} literal compiled as Set: map<K,V> m = {} previously produced a Value::Set at runtime, causing segfaults on map operations. Fixed by resolving {} type contextually during semantic analysis (SetOrMapLiteral) so codegen emits mux_new_map vs mux_new_set correctly.
• Struct layout corruption in interface-implementing classes: Inline constructor initialization used positional field indices instead of the interface-aware field map, causing the first real field's data to overwrite the vtable slot. Affected all classes implementing interfaces.
• Non-primitive field initialization in class constructors: Non-generic class constructors (e.g., Graph.new()) zero-initialized list/map/set fields as null instead of real empty collections.
• Generic class vtable generation crash: generate_class_vtables() attempted to build vtables using unspecialized method names (e.g., Graph.len) which do not exist; generic classes only have monomorphized instances. Vtable generation is now skipped for generic classes (interfaces use static dispatch).
• Cross-module import ordering: collect_hoistable_declarations() ran before imports were resolved, so classes in a file could not see imported interfaces during the hoisting pass. Imports are now processed during hoisting; expression_type_overrides from submodules are also merged so empty {} literals are correctly disambiguated. Closes #203.
• Type::Module panic: resolve_type_with_seen() and llvm_type_from_resolved_type() panicked on Type::Module instead of returning Err, breaking module.CONST.method() call patterns.
• Website frontend examples: Audited and corrected all code examples and interactive demos on the documentation site; removed a stale debug log from the compiler.
• Dependency vulnerabilities: Updated website and tooling dependencies to resolve known CVEs.

v0.3.2

[0.3.2] - 2026-06-13

Changed

• SonarQube quality issues resolved: Replaced unreachable!() in deep_clone_value for Value::Object inside containers, fixed UB in sync unlock arm, replaced 7 .expect() calls with proper error propagation, and extracted duplicate constructor helpers.
• Code duplication reduced: Overall project duplication dropped from 4.5% to 3.9%. Extracted module-level expression helpers in methods.rs, merged duplicate equality and return value arms in statements.rs, and added signature macros to compact ~40 runtime function declarations.
• Version metadata updated: All configuration files bumped from 0.3.1 to 0.3.2.

Fixed

• Segfault when running cargo test: LD_LIBRARY_PATH was checked before DT_RUNPATH, so the workspace .so was loaded instead of the cached release .so. Added -Wl,--disable-new-dtags to force DT_RPATH, which is checked before LD_LIBRARY_PATH.
• LLD linker flags: Removed -no-pie flag to fix LLD compatibility on modern Linux distributions.

v0.3.1

[0.3.1] - 2026-05-31

Changed

• Class constructor rules clarified and enforced: new is reserved for compiler-generated class constructors and cannot be user-defined in class bodies.
• Class creation guidance updated: Documentation now consistently describes class initialization as ClassName.new() followed by field assignment, or via named factory methods such as from(...) and with_<feature>(...).
• Version metadata updated: All configuration files (Cargo.toml, package.json, tree-sitter.json, README badge, PR template, VERSION) bumped from 0.3.0 to 0.3.1.
• Grammar and parser adjustments: Updated language grammar to reflect constructor rules, ensuring accurate syntax highlighting and parser diagnostics.

Fixed

• Parser diagnostic quality: Defining func new(...) in a class now reports one targeted parser error instead of cascading with a secondary Expected expression, found '}' error.
• Documentation and examples accuracy: Updated docs and examples that previously defined new or called class .new(...) with arguments so they match current language behavior.
• Stale runtime library cache: Cleared cached libmux_runtime.a that was missing newer symbols, preventing linker errors for enum-related runtime functions.

v0.3.0

Added

• Syntax highlighting support: Added TextMate and Tree-sitter grammar support with setup guidance for VSCode, Sublime Text, JetBrains, Neovim, and Helix.
• Setup documentation: New mux-website/docs/setup.md with language installation and editor configuration guides.

Changed

• Profiling decoupled: Removed built-in profiling infrastructure (mux-profiling crate) from compiler and runtime. Profiling now uses external tools (perf, Instruments, WPA) only.
• Code quality improvements: Pinned GitHub Actions versions, added --locked to cargo commands, added Cargo.lock files, refactored Python and JavaScript generators to fix SonarQube findings.

Fixed

• Code review cleanup: Removed orphaned profiling scripts, cleaned up empty scope blocks in compiler, and fixed numbered list in CONTRIBUTING.md.

v0.2.1

[0.2.1] - 2026-04-22

Changed

• Compiler maintainability work: Reduced complexity across compiler modules with a broad cleanup and refactor pass.
• Standard library internals: Refactored and optimized stdlib implementations for better consistency and maintainability.
• Developer workflow and project metadata: Updated AI agent guidance, OpenCode configuration, and supporting repository automation files.
• Documentation and website updates: Improved README content and landing page structure, examples, and installation guidance.

Fixed

• Codegen regressions: Fixed recent LLVM IR generation regressions and related import handling issues.
• Website behavior: Corrected landing page rendering details, including list key usage and stack example behavior.
• Build and CI support scripts: Fixed tooling and script issues affecting local and CI workflows.
• Versioning release prep: Synced release metadata and version-related files for 0.2.1.

Security

• Dependency and vulnerability updates: Applied dependency maintenance and vulnerability fixes, including Dependabot-driven updates.
• Static analysis cleanup: Addressed SonarCloud findings and code quality issues across the codebase.

v0.2.0

v0.2.0 changes

v0.1.2

Bug fixes for chaining stuff, function returns, switch/match statements, and references.