Mutare.Mutators.MapLiteral (mutare v0.1.0)

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Map-literal mutation: collapse a non-empty map literal %{…} to the empty map %{}. The map counterpart of Mutare.Mutators.List's non-empty-list collapse — it asks "does anything depend on this map's contents?". A weak suite that builds a map but never reads a key it carries lets the empty map survive.

What is not mutated

  • The empty map %{} — collapsing it to itself is a no-op.

  • A map update %{m | …} — not a literal; %{} would drop the base map m (a different operation, not a smaller version of the same one).

  • A struct's field map (%User{…}) — emptying it would drop required fields, so the inner %{} is left alone (the struct's field values still mutate).
  • The RHS of a guard in (when x in %{…}) — x in %{} ≡ false, which Mutare.Mutators.Conditional already produces. Body in expressions keep the collapse because left-side evaluation is observable.