Tya v0.49 Release Notes

Status: shipped. The tya version constant is 0.49.0 and ROADMAP.md carries the matching Released entry.

TL;DR

Three new CLI subcommands ship together as the first slice of the “Toolchain” track in ROADMAP.md § Future Work:

• tya new <name> — scaffold a new project (tya.toml + src/main.tya + .gitignore).
• tya task [name] [args...] — list and run tasks defined under a [tasks] table in tya.toml. POSIX sh -c is the execution shell. Trailing arguments are POSIX-quoted and appended to the task command.
• tya lint [paths...] — initial rule TYAL0001 unused local reports every unused local binding (variables and parameters).

The language surface is unchanged from v0.48. Programs that compiled under v0.48 keep compiling under v0.49.

What’s new

tya new

Creates a minimal project tree. The generated tya.toml already contains a sample [tasks] entry so you can tya task run straight after scaffolding:

$ tya new myapp
Created myapp
  cd myapp && tya task run
$ cd myapp && tya task run
Hello, Tya!

The v0.49 scaffold is intentionally minimal: no tests/, no README.md, no automatic git init. Larger templates are a follow-up minor.

tya task

Define recurring commands once in tya.toml:

[tasks]
ci      = "tya format && tya test"
release = ["tya build", "git tag v$(date +%Y%m%d)", "git push --tags"]

Run them by name:

$ tya task ci             # runs the string verbatim under /bin/sh -c
$ tya task release        # runs each array entry in order, stops on first failure
$ tya task ci -- --watch  # extra args are POSIX-quoted and appended
$ tya task                # lists every task in source order

Failure of an array-form task points at the failing entry:

[TYA-E0901] task "release" command #2 ("git tag v20260512") failed with exit code 128

tya lint

Run the linter over a file or directory. Findings go to stdout in path:line:col: TYAL0001 unused local "name" form, sorted by path/line/column. Exit 1 when any finding is reported, 0 when clean.

$ tya lint src
src/foo.tya:12:3: TYAL0001 unused local "tmp"
$ echo $?
1

The v0.49 rule set is exactly one rule. Additional rules (if true / dead code after return / suspicious for index patterns / --fix autofix) are a follow-up minor — the v0.49 scope is deliberately narrow so the CLI/output/exit-code contract can settle before the rule pipeline grows.

Implementation notes

• New diagnostic code range TYA-E090x is reserved for the three new subcommands (see SPEC § Diagnostic code registry).
• The [tasks] table is additive on top of the existing tya.toml manifest schema. v0.48 manifests parse unchanged.
• The manifest-discovery helper (walk up from pwd looking for tya.toml) was extracted into pkg.FindManifest and shared between the CLI’s existing projectRoot and the new tya task subcommand.
• internal/checker.CollectUnused(prog) is a new public API on top of the existing scope walker; it returns every unused binding instead of the first one (which CheckUnused still returns for --check-unused strict mode).

Compatibility

• Language: unchanged from v0.48.
• Manifest schema: backwards compatible — [tasks] is a new optional table.
• CLI: three new subcommands. No existing subcommands changed semantics. tya version reports 0.49.0.

Build environment fix

The compiled-program build path now passes -lm to cc on Linux and other non-Windows hosts so that math intrinsics (log2, exp, sin, cos, atan2, …) link successfully against glibc out of the box. Likewise runtime/tya_runtime.c now defines _XOPEN_SOURCE and _DEFAULT_SOURCE before any system header so strptime and friends are visible on strict glibc defaults (observed on recent Arch Linux). Both knobs are no-ops on macOS where the host libc already exposes these symbols.

Migration

Nothing to do. Optionally:

1. Add a [tasks] table to your project’s tya.toml.
2. Run tya lint on existing sources and clean up any unused locals it reports (or ignore — exit 1 is informational, not blocking, unless wired into CI).

Looking ahead

v0.50 (or later) candidates from ROADMAP.md § Future Work § Toolchain:

• Additional lint rules + --fix autofix
• tya doc source documentation generator
• tya lsp Language Server
• diagnostics pipeline migration (Parser → TYA-E01xx, Codegen → TYA-E06xx, Runner → TYA-E08xx)
• public Tya self-introspection library

Self-host v02 work (ROADMAP.md § Scheduled M8/M9/M10) remains deferred to the v1.0.0 prep window.