Tya v0.44 Release Notes

Status: shipped. The tya version constant is 0.44.0 and ROADMAP.md carries the matching Released entry.

TL;DR

v0.44 introduces a class-oriented namespace and entry-file model. Libraries become directories of PascalCase class files; entries become lowercase script files. The module keyword is on the way out (full removal lands at M9, after M8 self-host migration).

# v0.44 layout
project/
  main.tya                    # entry script (lowercase)
  Greeter.tya                 # sibling class file (PascalCase)
  lib/
    util/
      Logger.tya              # package member
      Cache.tya

# main.tya
import lib/util

logger = util.Logger()       # cross-package: <pkg>.<Class>
cache = util.Cache()
greeter = Greeter()          # same-directory sibling: bare ref
print(greeter.greet())

What’s new

Directory-as-package import

import path/to/pkg resolves to a directory containing class files. The path’s terminal segment becomes the in-scope binding. Packages nest to arbitrary depth via directories.

Class files

Every PascalCase .tya file declares one public class whose name matches the filename. Additional classes in the same file are private to the file. Class files may also declare interfaces.

Script files

Lowercase .tya files run via tya run. They may declare any number of private classes used at top level. Imports appear at the top.

Within-package bare references

Inside a package, a class file calls / extends / implements its sibling class files using the bare PascalCase name. The within-package fallback in the checker and codegen makes Request(...) / extends Animal / implements Encodable resolve to the sibling class without a prefix.

Same-directory siblings for entry scripts

A script entry sees PascalCase class files in its own directory without an explicit import. Useful for tiny multi-file projects that don’t yet need a package directory.

CLI surface (all six commands work with v0.44)

Command	Script	Class	Notes
`tya run`	yes	no	entry only
`tya build`	yes	no	entry only
`tya check`	yes	yes	class file → CheckClassFile
`tya format`	yes	yes	canonical syntax
`tya test`	yes	—	`*_test.tya`
`tya --tokens`	yes	yes	lexer dump
`tya --emit-c`	yes	yes	class file → standalone-compilable C
`tya --check-unused`	yes	yes	strict pass on class files too

Import path validation

The resolver rejects .., absolute paths, leading dotted prefixes, empty path segments, and PascalCase terminal segments. Cycle detection catches a → b → a through directory packages too.

Same-segment package collision

Two different directories whose paths share the terminal segment synthesize the same module name and would clobber each other in the merged source. The runner catches this at synthesis time with [TYA-E0855] package name conflict for both unaliased and aliased imports.

Diagnostic codes

v0.44 wires [TYA-EXXXX] inline prefixes on every new runtime error so users can grep for them in logs and cross-reference the SPEC table:

[TYA-E0400] — class file must define matching public class
[TYA-E0402] — class file may only contain import / class / interface
[TYA-E0403] — imports must precede classes
[TYA-E0404] — class file’s filename is not PascalCase
[TYA-E0405] — duplicate public class declaration
[TYA-E0850] — tya run invoked on a class file
[TYA-E0851] — invalid module name (path validation)
[TYA-E0852] — package contains a script file
[TYA-E0853] — package contains no class files
[TYA-E0854] — package directory name is not snake_case
[TYA-E0855] — same-segment package conflict

E0406 (cross-file private class) and E0200 (module keyword removal) remain reserved pending M5 and M9 respectively.

Stdlib migration (19 of 27 packages)

path, random, hex, base64, digest, secure_random
process, dir, file, os, math, csv, matrix, json, toml, url
unittest, value, markdown

Held back for v0.1 self-host compatibility:

string, array, dict — referenced by the v0.1 self-host compiler tests

Held back for working-tree cleanup:

runtime, time, channel, sync, task

The held-back packages migrate alongside M8 self-host migration (string/array/dict) and M7 examples migration (the rest).

Compatibility notes

The legacy module name + functions shape continues to work through v0.44 to keep the v0.1 self-host fixed point green and to give users an incremental migration path. M9 removes module entirely.
Existing examples, the self-host compiler, and held-back stdlib packages still use the legacy form.
The tya format and tya check paths now accept class files; this is a new surface, not a behavior change.

Migration guide

A practical companion document lives at docs/v0.44/MIGRATION.md. It walks the mechanical recipe: file naming, the module name → class Name + @@method conversion, internal cross-method calls, sibling auto-visibility, package directory rules, and the CLI command matrix.

Known limitations / follow-ups

M5 cross-file private enforcement — the SPEC says private classes must not be referenced from other files; the current source-concat synthesis pipeline doesn’t carry the necessary OriginFile metadata to enforce this. Fix pairs with M8.
String / array / dict still in legacy module form.
tya emit-c on class file emits a trivial main; the output compiles but does nothing. This is not a bug, just a consequence of class files having no entry-point semantics.

Testdata

22 testscript files under tests/testdata/v44/ pin the new behavior end-to-end. See tests/testdata/v44/README.md for the catalogue. Add a new pin by creating a new *.txtar (don’t expand existing ones).