writeonce/docs/plan/discarded.md

Discarded — settled rejections

Decisions that were considered and rejected, with the reason. This file exists so a settled question is not re-proposed. If you want to revisit an entry, argue against the reason recorded here — do not re-open it as if it were new.

Status board: 00-status.md · Doctrine: ../00-principles.md

Language surface

Rejected	Date	Reason
Inheritance — extends, super, override, implements	plan 13 / OOP spec	No hierarchies, ever. Is-a is a tagged union, has-a is composition, polymorphism is structural interfaces. Hierarchies fossilize early guesses and make dispatch, ownership, and diagnostics all harder. Principle 4.
abstract newtypes (abstract Money = Int)	2026-08-10	Flipped adopt → reject in the systems-track verdict table. A distinct scalar type adds a conversion surface without buying safety this language needs; domain scalars stay plain Int/Text. The Money/SKU stopgap allowlist that stood in for the unbuilt feature proved the cost was real. Haxe-parity's abstract+is task was deleted outright — abstract rejected here, is cut for zero uses in the driving workload.
Money, SKU as language types	2026-08-10	Removed from builtin_scalars and from the abstract allowlist. Money → Int (minor units), SKU → Text everywhere.
Float as a builtin scalar	2026-08-10	Phantom: it was in builtin_scalars and documented as f64, but token.ml has no float literal and wob.h has no float kind — ratio: Float typechecked while no Float value could ever be written or represented. Re-add only when literals and a wob float kind land together.
Dynamic / untyped	systems-track spec	Static typing is the untagged-register VM's foundation. Typed json.decode … as T -> ?T covers the real use. Principle 13.
cast	systems-track spec	No unsafe casts. Conversions are typed; as exists only in the decode-target position.
macro	systems-track spec	Kills the fast-compile promise. Codegen belongs to wo gen tooling.
extern / FFI	systems-track spec	One FFI hole voids the whole memory-safety story. Capabilities are audited typed builtins. Principle 10.
operator overloading, overload	systems-track spec	One name, one signature. Keeps dispatch and diagnostics simple.
inline functions	systems-track spec	Optimization is the compiler's job. const compile-time values are adopted; inline functions are not.
User-definable generic containers	OOP spec §3	multi and map are runtime-provided native classes implemented in C. The VM picks the backing data structure; the language exposes only the ADT's operations.

Compiler / VM architecture

Rejected	Reason
AOT compilation to C	Kills hot reload and makes builds slow. A register bytecode interpreter with computed-goto dispatch ships first; a JIT stays possible later.
Approach B — "Lua-shaped minimal" VM	Defers the project's core risk (the hybrid borrow VM) and adds a Menhir dependency.
Approach C — "Rust-lite static regions"	Research-grade complexity; recreates exactly the Rust ergonomics pain that mutable value semantics exists to avoid.
Menhir, ppx, any opam package	OCaml stdlib only; handwritten lexer and recursive-descent parser. dune is a build runner, nothing more.
First-class borrows (storable, returnable)	Second-class borrows (Hylo/Val mutable value semantics) eliminate full lifetime inference — the compiler needs only per-function flow analysis. Long-lived links go through ref T ids or @gc.
Empty-list stub for is_abstract_type	2026-08-10: a function that can never return true is dead code. Deleted outright instead.

Runtime / deployment

Rejected	Reason
Arc<Mutex<Engine>> / any shared mutable engine state	Thread-per-core shards each own their engine, heap, and event loop; cross-shard work is an ownership-moving message send. Principle 5.
External deployer daemon	Violates two-VMs-in-one-runtime and splits the data plane. The management plane is a runtime module with a thin CLI.
Self-hosted .wo deploy logic	Bootstrap problem — the deploy path cannot be written in the language whose deployment it implements. Recorded as a much-later possibility.
Script-based / destructive schema migrations (v1)	Additive-only auto-diff is what makes rollback unconditional: the previous version ignores fields and classes it never knew. Destructive changes reject at propose time.
Portability abstractions over Linux	Targeting one kernel lets the runtime use its sharpest primitives directly instead of the lowest common denominator. Principle 9.
Mirrors on the commit path	The Postgres mirror is a reconstructible backup. RAM is authoritative; reads and acks never depend on it. Principle 7.

Process / docs

Rejected	Reason
Per-example principle.md files	2026-08-08: one canonical repo-level docs/00-principles.md instead; examples link to it.
Minimal 3-file log-watcher sample	Breaks the file-for-file .hx → .wo mapping and leaves the "could not express" column unproven — which is the sample's entire acceptance criterion.
Raw code in plan documents	Plans carry concept, reason, and required behavior in words; the executor writes the code.