Tuples have no rest pattern or spread over their numeric-label row

GAP-TYPES-009

A tuple cannot be split into its first element and the rest, or extended, in a generic body.

Lifecycle

known

Owner

language

Scope

reference/spec/types.md#tuples

Origin

RFC-0178 review

Affects · linked records

spec.types.tuples.legality-1language spec rule

gapKnown gaps ↗

Gap

A tuple cannot be split into its first element and the rest, or extended, in a generic body. If RFC-0151 makes tuples rows with numeric labels, RFC-0178's forms could apply, but whether (a, ..rest) yields a re-indexed tuple (rest.0 is the old .1) or keeps the original labels is that RFC's decision, not RFC-0178's.

Impact

Visible to Metel programmers: variadic-style tuple code (a head/tail) has no generic spelling; use a record or a fixed arity.

Affects

• spec.types.tuples.legality-1

Resolution

Not scheduled. Decide together with RFC-0151.