Tya v0.54 Release Notes

Status: shipped. tya version reports 0.54.0 and ROADMAP.md carries the matching Released entry.

TL;DR

v0.54 finishes the diagnostics pipeline migration:

• Parser, Codegen, and Runner errors now flow through the same diag.Diagnostic channel as Lexer and Checker — every error carries a stable [TYA-EXXXX] code.
• The parser keeps going past one error, so a single tya check run surfaces every top-level statement violation.
• Undefined-name errors gain did you mean "…"? suggestions driven by a tiny new internal/util Levenshtein helper.

The language surface is unchanged from v0.53.

What’s new

Structured diagnostics for Parser / Codegen / Runner

$ tya check bad.tya
-- RETURN MUST BE INSIDE A FUNCTION ---- bad.tya:1:1

return must be inside a function near "return"

   1 | return 42
       ^

(TYA-E0120)

-- BREAK MUST BE INSIDE A LOOP -------- bad.tya:2:1
…

New code bands:

• TYA-E0100-0199 Parser (expected token, indented block, position constraint, reserved name, pattern syntax, expression).
• TYA-E0601-0606 Codegen (unsupported AST shapes).
• TYA-E0840-0858 Runner (filename, entry-module conflict, import name conflict, undefined variable).

Multi-error parsing

block() and program() now run statement-level recovery: after recording a diagnostic, the parser skips to NEWLINE / DEDENT / EOF and resumes. Every diagnostic flows out as a *parser.ParserError{Diags: []diag.Diagnostic}.

The LSP server (internal/lsp/diagnostics.go) and CLI (cmd/tya/main.go) both errors.As-unwrap the wrapper and emit the full list.

did-you-mean hints

$ tya check typo.tya
typo.tya:2:7: undefined variable strng; did you mean "string"?

The new internal/util/strdist.go::Suggest returns up to three candidates with Levenshtein distance ≤ 2, drawing from the builtin function list and the current scope’s defined names.

Compatibility

• Language surface: unchanged from v0.53.
• tya.toml schema: unchanged.
• CLI: every existing subcommand keeps its v0.53 behaviour. Stderr formatting changes are additive (banner + code) and existing tests that grep substring like "undefined variable" continue to match.

Migration

Nothing required. Optional:

1. Upgrade to v0.54 (brew install komagata/tap/tya).
2. Re-run tya check on existing source — you’ll see every diagnostic in one pass instead of just the first.
3. Consume the new [TYA-EXXXX] codes in your editor / CI lint rules.

Implementation notes

• New helpers:
  • internal/util/strdist.go — Levenshtein + Suggest
  • internal/parser/{codes,classify,diagnostic,recovery}.go — structured errors + multi-error scaffolding
  • internal/codegen/errors.go — CodegenError wrapper
  • internal/runner/errors.go — RunnerError + undefinedNameHint
  • internal/checker/suggest.go — checker-side undefined-name hint formatting
• The parser keeps the legacy line:col: msg near "tok" format on *ParserError.Error() so existing string-grep tests stay green; structured payload lifts out via errors.As.
• LSP and CLI both unwrap *parser.ParserError, *runner.RunnerError, and *codegen.CodegenError into the shared emitDiagnostics renderer.

Tests

• tests/testdata/v54_diag/multi_error.txtar — three top-level position constraint violations surface in one pass.
• tests/testdata/v54_diag/did_you_mean.txtar — typo’d identifier gets the did you mean …? hint.
• All pre-existing tests stay green.

Looking ahead (v0.55+ candidates)

From ROADMAP.md § Future Work:

• Parser signature change (Parse() → (*Program, []Diag, error))
• Expression-level recovery
• Codegen / Runner signature change for []Diag slices
• LSP code actions for did-you-mean quick fixes
• VS Code Marketplace publication (still queued from v0.53)
• Toolchain track other Epics (tya lint v3, tya task v2, tya doc v2)
• Language Epics (raw " in {expr} interpolation, primitive class sugar, interface stackable trait, WASM target)

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