Class CopyConstructor

java.lang.Object
org.ek9lang.compiler.support.CopyConstructor
All Implemented Interfaces:
Function<IAggregateSymbol, Optional<MethodSymbol>>
public final class CopyConstructor extends Object implements Function<IAggregateSymbol, Optional<MethodSymbol>>
THE copy constructor of a type: a PUBLIC constructor taking exactly one argument of EXACTLY that type - Step(Step). Hold one and ask it, do not re-derive it.

🔑 Exact type, never a promotion or a super. A constructor taking a wider type (Step(Any), a trait, the super) or one reached through #^ does not make an independent value of the SAME type, so it is not a copy constructor. The match is drawn on isExactSameType - symbol identity, never a name.

A generic's conceptual T always has one (CommonFactory gives every type parameter a constructor per type parameter, so T(item as T)); a range over T marks it ACCESSED_BY_RANGE, so the type a generic is parameterised with - constrained T included - must have its own, by THIS predicate (phase 4, E08272; Steve R1/R3, 2026-10-07).

Users: the alias/constrained-type copy (phase2/PopulateConstrainedTypeOrError, E06131 - the ONLY copy since decision D10), the for-range rule (phase3/ForRangeOrError, E08272), its parameterisation check (phase4/ParameterisedTypeOrError) and the for-range IR (phase7/generator/ RangeIterationHelper: counter = T(start), loop variable = T(counter); Contract 15). Extracted 2026-10-07 from PopulateConstrainedTypeOrError.takesExactlyTheBase when the range copy became a copy-constructor call (Steve, RANGE COPY decision).