Tya v0.63 Release Notes

v0.63 advances the Tya-written self-host compiler under selfhost/v02/ to a current-spec proof gate. The Go implementation remains the active reference, but v02 now has focused lexer/parser, checker, C emitter, and fixed-point coverage for representative current language families.

Language

• Function literals in the active compile-to-C path now support lexical closures over enclosing function parameters and locals. Captures snapshot the current TyaValue, so heap-backed values remain shared values without deep copying.
• Closure bodies may read captured bindings, pass closures through higher-order APIs, and use captured closures with spawn / await. Direct reassignment to an outer binding and indexed or member mutation through a captured binding are rejected.

Self-Host

• selfhost/v02/compiler.tya recognizes current syntax families including imports with paths and aliases, interfaces, class modifiers, implements, scope, try/catch, raise, match, select, spawn, await, embed, raw/bytes/triple/tagged strings, heredocs, predicate names, and bitwise/shift parsing.
• The v02 checker validates selected current semantic families, including import bindings, interface contracts, class context for self/super/Self, control-flow traversal, select arm bindings, and single-file embed existence.
• The v02 C emitter handles selected current runtime families, including single-file embed, interface/implements declarations that erase for runtime, class dispatch, interpolation, primitive string helpers, and deterministic unsupported-codegen diagnostics for parsed forms that v02 does not emit yet.
• TestSelfhostV02Scripts now documents the applicable v02 full-spec coverage and proves the v02 stage-2/stage-3 fixed point.
• The v02 fixed-point gate also checks that every .tya file under selfhost/v02/ can be compiled by stage 1.

Roadmap

• ROADMAP.md now distinguishes the completed selfhost/v02/ current-spec proof from the later v1.0 work to remove the Go reference implementation and ship bootstrap binaries.

Verification

The release gate is:

go test ./... -count=1

The published v0.63.0 tag passed the full suite, including the maintained v01 and v02 self-host fixed-point tests.