Sword 0.3.1 — Quench

2026-10-30. A patch to Quench: the race checker closes a hole in partitions
and stops refusing the parent's own uses, and two smaller mistakes are fixed.

What changes for existing programs

One kind of program that compiled stops compiling, against what a patch
promises, because each of them is a data race the race checker was meant to
refuse. A piece of a chunks partition belongs to its task for one turn of the
loop that cut it; the checker took it to belong to it for good. Now refused:
nested chunks loops that spawn with a piece of each, a loop around the
chunks loop or inside it, two spawns given one piece in a turn, and the parent
writing a piece beside its task (#135). A spawn in each branch of an if and
the parent reading part.len are still fine. Everything else that compiled
still does.

Fixes

• Inside a scope, the parent reading a local of its own and then writing it
  was refused as a race. Its own uses run one after another and race only with
  its tasks (#136).
• Lending one counter or struct to every task of a loop came with a note to
  walk it with chunks, which only a slice has. The note now says atomic[T]
  for an integer or a bool, shared[T] with lock for anything else, and
  a[..].chunks(n) for an array (#137).
• A package constant as an array length in a generic struct's field, a generic
  method's parameter or a generic function's parameter was "not an integer
  constant" (#138).