Method opt

basex-core/src/main/java/org/basex/query/func/map/MapKeys.java:20–27

(final CompileContext cc)

  }

  @Override
  protected Expr opt(final CompileContext cc) {
    final Expr map = arg(0);
    if(map.seqType().type instanceof final MapType mt) {
      exprType.assign(mt.keyType().seqType(Occ.ZERO_OR_MORE), map.structSize());
    }
    return this;
  }
}