inline void walkObjectsImpl()

in src/RStuff/RUtil.h [314:396]
81 lines of code
26 McCabe index (conditional complexity)

inline void walkObjectsImpl(Func const& f, std::unordered_set<SEXP> &visited, SEXP x) {
  if (x == R_NilValue || x == R_UnboundValue || TYPEOF(x) == CHARSXP || visited.count(x)) return;
  visited.insert(x);
  f(x);
  switch (TYPEOF(x)) {
    case SYMSXP: {
      walkObjectsImpl(f, visited, PRINTNAME(x));
      walkObjectsImpl(f, visited, SYMVALUE(x));
      walkObjectsImpl(f, visited, INTERNAL(x));
      break;
    }
    case DOTSXP:
    case LANGSXP:
    case LISTSXP: {
      // sxpinfo.extra may contain an immediate binding, meaning that CAR(x) should not be called
      // See: https://github.com/r-devel/r-svn/blob/trunk/doc/notes/immbnd.md
      if (!x->sxpinfo.extra) walkObjectsImpl(f, visited, CAR(x));
      walkObjectsImpl(f, visited, CDR(x));
      walkObjectsImpl(f, visited, TAG(x));
      break;
    }
    case CLOSXP: {
      walkObjectsImpl(f, visited, FORMALS(x));
      walkObjectsImpl(f, visited, BODY(x));
      walkObjectsImpl(f, visited, CLOENV(x));
      break;
    }
    case ENVSXP: {
      if (x == R_BaseEnv || x == R_BaseNamespace) {
        ShieldSEXP names = RI->ls(R_BaseEnv, named("all.names", true));
        if (names.type() == STRSXP) {
          int length = names.length();
          for (int i = 0; i < length; ++i) {
            walkObjectsImpl(f, visited, RI->baseEnv.getVar(stringEltNative(names, i), false));
          }
        }
      } else if (x != R_EmptyEnv) {
        walkObjectsImpl(f, visited, ENCLOS(x));
        walkObjectsImpl(f, visited, FRAME(x));
        walkObjectsImpl(f, visited, HASHTAB(x));
      }
      break;
    }
    case PROMSXP: {
      walkObjectsImpl(f, visited, PRVALUE(x));
      walkObjectsImpl(f, visited, PRCODE(x));
      walkObjectsImpl(f, visited, PRENV(x));
      break;
    }
    case STRSXP: {
      R_xlen_t length = Rf_xlength(x);
      for (R_xlen_t i = 0; i < length; ++i) {
        walkObjectsImpl(f, visited, STRING_ELT(x, i));
      }
      break;
    }
    case EXPRSXP:
    case VECSXP: {
      R_xlen_t length = Rf_xlength(x);
      for (R_xlen_t i = 0; i < length; ++i) {
        walkObjectsImpl(f, visited, VECTOR_ELT(x, i));
      }
      break;
    }
    case BCODESXP: {
      walkObjectsImpl(f, visited, BCODE_CODE(x));
      walkObjectsImpl(f, visited, BCODE_CONSTS(x));
      walkObjectsImpl(f, visited, BCODE_EXPR(x));
      break;
    }
    case EXTPTRSXP: {
      walkObjectsImpl(f, visited, EXTPTR_PROT(x));
      walkObjectsImpl(f, visited, EXTPTR_TAG(x));
      break;
    }
    case WEAKREFSXP: {
      walkObjectsImpl(f, visited, R_WeakRefKey(x));
      walkObjectsImpl(f, visited, R_WeakRefValue(x));
      break;
    }
  }
  walkObjectsImpl(f, visited, ATTRIB(x));
}