ArgMojo v0.5.0

20260404 (v0.5.0)

ArgMojo v0.5.0 introduces the struct-based declarative API — define a Parsable struct with typed wrapper fields (Option, Flag, Positional, Count), call MyArgs.parse(), and get typed results. The declarative API coexists with the existing builder API and bridges between them via to_command() / parse_from_command(). This release also adds asterisk-masked password input and reorganises internal modules.

ArgMojo v0.5.0 targets Mojo v0.26.2.

⭐️ New in v0.5.0

1. Declarative API core — Parsable trait with compile-time reflection over wrapper-typed fields. Conforming structs need only declare fields and provide description(); all parsing, Command-building, and write-back methods are provided as trait defaults (PR #34, #35, #37, #40).
2. Wrapper types — Option[T, ...], Flag[...], Positional[T, ...], Count[...] parametric structs encode CLI metadata as compile-time parameters. Conform to the internal ArgumentLike trait with add_to_command() / read_from_result() hooks (PR #34).
3. Auto-initialisation — Parsable.__init__ uses mark_initialized + comptime for + UnsafePointer.init_pointee_move to default-construct all fields via reflection. Users never need to write __init__ (PR #37).
4. Hybrid bridge — to_command() reflects a Parsable struct into an owned Command for builder-level customisation; parse_from_command(cmd^) parses back into a typed struct (PR #35, #40).
5. Dual-return parsing — parse_full() returns Tuple[Self, ParseResult] for workflows that need both typed struct fields and raw ParseResult access (e.g. subcommand dispatch). parse_full_from_command(cmd^) does the same from a pre-configured Command (PR #40, #42).
6. Subcommand support — subcommands() hook on Parsable returns List[Command]; called automatically by to_command() for recursive tree assembly. run(self) method for leaf command execution. from_parse_result() for typed write-back from subcommand results (PR #39, #43).
7. Asterisk-masked password input — .password[True]() on Argument echoes * for each keystroke (sudo-rs style), complementing the existing .password() which hides input entirely. Uses raw terminal mode with ICANON/ISIG disabled (PR #32).

🦋 Changed in v0.5.0

1. Remove Arg alias for Argument and drop ArgumentLike from the public export list. The public API now exports: Argument, Command, ParseResult, Parsable, Option, Flag, Positional, Count (PR #42).
2. subcommands() hook signature changed from subcommands(mut cmd: Command) raises to subcommands() raises -> List[Command] — returns a list of Commands instead of mutating one (PR #43).
3. Reorganise Argument and Command source files into clearly grouped internal sections for readability (PR #33).

📚 Documentation and testing in v0.5.0

• Add docs/declarative_api_planning.md — comprehensive design document for the declarative API (PR #33).
• Add 4 declarative examples: search.mojo (pure declarative), deploy.mojo (hybrid), convert.mojo (full parse + extra builder args), jomo.mojo (subcommands with hybrid tree) (PR #41).
• Add 4 test modules: test_wrappers.mojo (wrapper defaults, copy/move, Flag.__bool__), test_declarative.mojo (to_command, parse_args, from_parse_result), test_hybrid.mojo (builder customisation, mutually exclusive, implies, configure pattern), test_subcommands_declarative.mojo (flat/nested subcommands, run() dispatch, dual return) (PR #38, #39).
• Add test_interactive.mojo for interactive prompting edge cases (PR #33).
• Add method matrix table to README, user manual, and planning doc.
• Update README with declarative API Quick Start, examples table, and project structure.
• Update user manual with declarative API usage guide, full-parse section, and API summary.

What's Changed

• [core] Enable asterisk-masked password input by @forfudan in #32
• [doc] Add a planning file for declarative API + Reorganize Command/Argument internals for clearer grouping by @forfudan in #33
• [core][declarative] Implement argument wrappers and Parsable trait by @forfudan in #34
• [core][declarative] Implement Parsable reflection, trait methods, and example by @forfudan in #35
• [core][declarative] Use rebind instead of UnsafePointer in argument wrapper write-back logic by @forfudan in #36
• [core][declarative] Default-initialize all fields via reflection in __init__ of Parsable trait by @forfudan in #37
• [core][declarative] Add tests for hybrid declarative + builder API by @forfudan in #38
• [core][declarative] Add tests for declarative subcommands by @forfudan in #39
• [core][declarative] Consolidate Parsable trait functions into methods by @forfudan in #40
• [core][declarative] Add more examples of declarative API by @forfudan in #41
• [core][declarative][doc] Enrich documentation and rename some methods by @forfudan in #42
• [core][declarative] Update to_command so that it returns a list of Command by @forfudan in #43
• [declarative][doc] Standardize Parsable parsing method names + Update documents for release by @forfudan in #44

Full Changelog: v0.4.0...v0.5.0