Class Reg<V, N, F, L>

Name this capture so bind exposes it as a handle (copy/of/star).

Bind named captures (.as) to editable handles over source: a string capture → Writable<Str>, a star capture → Arr<string>.

Pass opts.schema ({ name: "str" | "arr" }) for known keys and per-handle types without casts.

Bind named captures (.as) to editable handles over source: a string capture → Writable<Str>, a star capture → Arr<string>.

Pass opts.schema ({ name: "str" | "arr" }) for known keys and per-handle types without casts.

Attach a codec to a copy leaf, turning it into a typed of capture.

Parse s fully (must consume to the end); null if it doesn't match. Single-pass and linear.

This grammar as a first-class, composable Optic<string, V>: get parses (falling back to the default value off-language), put reprints and round-trip-guards (an off-language source or a non-round-tripping value leaves the source untouched). Drops straight into compose(...) and cell.through(...), so it chains with atKey/iso and string lenses like caseFold.

opt(this). Only available when this is non-nullable.

alt(this, other).

Iterate one-or-more (forbids the empty list when unseparated).

Reflective print: render a value back to source text.

Source spans of each named capture, keyed by name — the get/put correspondence made visible. Empty if s doesn't fully match.

Iterate zero-or-more, optionally separated by sep; binds to an Arr. A separated star is a split (≥1 piece, like Str.split). Pass opts.key for resourceful alignment across reorders.

Does s fully match? Linear.

seq(this, ...next). A provably-overlapping boundary between this and the next part is a type error — so a.then(b).then(c) statically checks every link. Interior boundaries of a multi-arg call, and the copy/of escapes, are checked at construction (throws).

The whole abstract value as a writable lens over source.

Ordered union; branches must be first-disjoint (checked).

The escape hatch: capture the text matched by an arbitrary regular re. Non-regular constructs (anchors, lookaround, backreferences) throw. The boundary is opaque to the type system (AnyBound), so adjacency can't be checked at compile time — the construction-time check still applies.

One or more digits, \d+, as a string.

One or more digits, decoded as a number (a quotient lens — leading zeros are not preserved).

One or more ASCII letters, [A-Za-z]+.

A fixed delimiter: matched and printed, never surfaced as a value.

Typed escape hatch: re recognizes, codec decodes/encodes.

Optional (part or nothing). part must be non-nullable. The value is the inner value when present and null when absent; an optional with no value of its own (e.g. lit(...).optional()) records presence as true.

Unambiguous concatenation; every boundary is checked here and throws on ambiguity. (For compile-time adjacency checking, prefer the fluent a.then(b).then(c), which validates each link.)

Text up to (but not including) the delimiter c — i.e. [^c]*. Nullable (an empty field is allowed); the natural companion of star(lit(c)).

One or more word characters, \w+ (letters, digits, underscore).