Roadmap¶

This page tracks API direction and current implementation status.

Status labels: - FINISHED: already shipped and documented. - WIP: currently being designed or prepared. - NEXT: future consideration, not yet committed.

FINISHED¶

Completed in v0.9.3:

pred(callable) predicate pattern for lifting arbitrary unary predicates into first-class patterns.

Completed in v0.9.2:

any(ps...), all(ps...) pattern combinators with OR/AND semantics.

Completed in v0.9.1:

val<V> static literal entry point.
C++20 floating-point static literals through val<V>.
Canonical structural entry has<...> (factory-style has<...>() removed from public API).

WIP¶

Current workstream for upcoming releases.

`neg(p)` — negation pattern¶

Invert the result of a sub-pattern.

match(x) | on(
  neg(val<0>) >> "non-zero",
  _ >> "zero"
);

NEXT¶

Potential follow-up items after current WIP scope is stabilized.

`some` / `none` — `std::optional` patterns¶

Dedicated patterns for the two states of std::optional.

std::optional<int> v = 42;
match(v) | on(
  $(some) >> [](int x) { return x; },
  none >> 0
);

Design Principles for New API¶

Stateless compile-time patterns should be variable templates, not function templates that return default-constructed objects.
Function template forms are reserved for patterns that require runtime arguments (e.g., lit(value), lit_ci(value), rng(lo, hi)).
Names should be short, lowercase, and read naturally in the DSL.