
  [;1m-spec process_info(Pid, Item) -> InfoTuple | [] | undefined[0m
  [;1m                      when[0m
  [;1m                          Pid :: pid(),[0m
  [;1m                          Item :: process_info_item(),[0m
  [;1m                          InfoTuple :: process_info_result_item();[0m
  [;1m                  (Pid, ItemList) -> InfoTupleList | [] | undefined[0m
  [;1m                      when[0m
  [;1m                          Pid :: pid(),[0m
  [;1m                          ItemList :: [Item],[0m
  [;1m                          Item :: process_info_item(),[0m
  [;1m                          InfoTupleList :: [InfoTuple],[0m
  [;1m                          InfoTuple :: process_info_result_item().[0m

  Types:
    -type max_heap_size() ::
          Size ::
              non_neg_integer() |
              #{size => non_neg_integer(),
                kill => boolean(),
                error_logger => boolean()}.
    -type message_queue_data() :: off_heap | on_heap.
    -type priority_level() :: low | normal | high | max.
    -type process_info_item() ::
          backtrace | binary | catchlevel | current_function |
          current_location | current_stacktrace | dictionary |
          error_handler | garbage_collection | garbage_collection_info |
          group_leader | heap_size | initial_call | links | last_calls |
          memory | message_queue_len | messages | min_heap_size |
          min_bin_vheap_size | monitored_by | monitors |
          message_queue_data | priority | reductions | registered_name |
          sequential_trace_token | stack_size | status | suspending |
          total_heap_size | trace | trap_exit.
    -type process_info_result_item() ::
          {backtrace, Bin :: binary()} |
          {binary,
           BinInfo ::
               [{non_neg_integer(),
                 non_neg_integer(),
                 non_neg_integer()}]} |
          {catchlevel, CatchLevel :: non_neg_integer()} |
          {current_function,
           {Module :: module(), Function :: atom(), Arity :: arity()} |
           undefined} |
          {current_location,
           {Module :: module(),
            Function :: atom(),
            Arity :: arity(),
            Location ::
                [{file, Filename :: string()} |
                 {line, Line :: pos_integer()}]}} |
          {current_stacktrace, Stack :: [stack_item()]} |
          {dictionary, Dictionary :: [{Key :: term(), Value :: term()}]} |
          {error_handler, Module :: module()} |
          {garbage_collection, GCInfo :: [{atom(), non_neg_integer()}]} |
          {garbage_collection_info,
           GCInfo :: [{atom(), non_neg_integer()}]} |
          {group_leader, GroupLeader :: pid()} |
          {heap_size, Size :: non_neg_integer()} |
          {initial_call, mfa()} |
          {links, PidsAndPorts :: [pid() | port()]} |
          {last_calls, false | (Calls :: [mfa()])} |
          {memory, Size :: non_neg_integer()} |
          {message_queue_len, MessageQueueLen :: non_neg_integer()} |
          {messages, MessageQueue :: [term()]} |
          {min_heap_size, MinHeapSize :: non_neg_integer()} |
          {min_bin_vheap_size, MinBinVHeapSize :: non_neg_integer()} |
          {max_heap_size, MaxHeapSize :: max_heap_size()} |
          {monitored_by,
           MonitoredBy :: [pid() | port() | nif_resource()]} |
          {monitors,
           Monitors ::
               [{process | port,
                 Pid ::
                     pid() |
                     port() |
                     {RegName :: atom(), Node :: node()}}]} |
          {message_queue_data, MQD :: message_queue_data()} |
          {priority, Level :: priority_level()} |
          {reductions, Number :: non_neg_integer()} |
          {registered_name, [] | (Atom :: atom())} |
          {sequential_trace_token,
           [] | (SequentialTraceToken :: term())} |
          {stack_size, Size :: non_neg_integer()} |
          {status,
           Status ::
               exiting | garbage_collecting | waiting | running |
               runnable | suspended} |
          {suspending,
           SuspendeeList ::
               [{Suspendee :: pid(),
                 ActiveSuspendCount :: non_neg_integer(),
                 OutstandingSuspendCount :: non_neg_integer()}]} |
          {total_heap_size, Size :: non_neg_integer()} |
          {trace, InternalTraceFlags :: non_neg_integer()} |
          {trap_exit, Boolean :: boolean()}.
    -type stack_item() ::
          {Module :: module(),
           Function :: atom(),
           Arity :: arity() | (Args :: [term()]),
           Location ::
               [{file, Filename :: string()} |
                {line, Line :: pos_integer()}]}.

  Returns information about the process identified by [;;4mPid[0m, as
  specified by [;;4mItem[0m or [;;4mItemList[0m. Returns [;;4mundefined[0m if the
  process is not alive.

  If the process is alive and a single [;;4mItem[0m is specified, the
  returned value is the corresponding [;;4mInfoTuple[0m, unless [;;4mItem =:=[0m
  [;;4mregistered_name[0m and the process has no registered name. In this
  case, [;;4m[][0m is returned. This strange behavior is because of
  historical reasons, and is kept for backward compatibility.

  If [;;4mItemList[0m is specified, the result is [;;4mInfoTupleList[0m. The [;;4m[0m
  [;;4mInfoTuple[0ms in [;;4mInfoTupleList[0m are included with the corresponding [;;4m[0m
  [;;4mItem[0ms in the same order as the [;;4mItem[0ms were included in [;;4mItemList[0m.
  Valid [;;4mItem[0ms can be included multiple times in [;;4mItemList[0m.

  Note:
    If [;;4mregistered_name[0m is part of [;;4mItemList[0m and the process has
    no name registered, a [;;4m{registered_name, []}[0m, [;;4mInfoTuple[0m 
    will be included in the resulting [;;4mInfoTupleList[0m. This
    behavior is different when a single [;;4mItem =:= registered_name[0m
    is specified, and when [;;4mprocess_info/1[0m is used.

  Valid [;;4mInfoTuple[0ms with corresponding [;;4mItem[0ms:

  [;;4m[;;4m{backtrace, Bin}[0m[0m:
    Binary [;;4mBin[0m contains the same information as the output from [;;4m[0m
    [;;4merlang:process_display(Pid, backtrace)[0m. Use [;;4mbinary_to_list/1[0m
    to obtain the string of characters from the binary.

  [;;4m[;;4m{binary, BinInfo}[0m[0m:
    [;;4mBinInfo[0m is a list containing miscellaneous information about
    binaries on the heap of this process. This [;;4mInfoTuple[0m can be
    changed or removed without prior notice. In the current
    implementation [;;4mBinInfo[0m is a list of tuples. The tuples
    contain; [;;4mBinaryId[0m, [;;4mBinarySize[0m, [;;4mBinaryRefcCount[0m.

    The message queue is on the heap depending on the process flag [;;4m[0m
    [;;4mmessage_queue_data[0m.

  [;;4m[;;4m{catchlevel, CatchLevel}[0m[0m:
    [;;4mCatchLevel[0m is the number of currently active catches in this
    process. This [;;4mInfoTuple[0m can be changed or removed without
    prior notice.

  [;;4m[;;4m{current_function, {Module, Function, Arity} | undefined}[0m[0m:
    [;;4mModule[0m, [;;4mFunction[0m, [;;4mArity[0m is the current function call of
    the process. The value [;;4mundefined[0m can be returned if the
    process is currently executing native compiled code.

  [;;4m[;;4m{current_location, {Module, Function, Arity, Location}}[0m[0m:
    [;;4mModule[0m, [;;4mFunction[0m, [;;4mArity[0m is the current function call of
    the process. [;;4mLocation[0m is a list of two-tuples describing the
    location in the source code.

  [;;4m[;;4m{current_stacktrace, Stack}[0m[0m:
    Returns the current call stack back-trace (stacktrace) of
    the process. The stack has the same format as in the [;;4mcatch[0m
    part of a [;;4mtry[0m. See The call-stack back trace (stacktrace).
    The depth of the stacktrace is truncated according to the [;;4m[0m
    [;;4mbacktrace_depth[0m system flag setting.

  [;;4m[;;4m{dictionary, Dictionary}[0m[0m:
    [;;4mDictionary[0m is the process dictionary.

  [;;4m[;;4m{error_handler, Module}[0m[0m:
    [;;4mModule[0m is the error handler module used by the process (for
    undefined function calls, for example).

  [;;4m[;;4m{garbage_collection, GCInfo}[0m[0m:
    [;;4mGCInfo[0m is a list containing miscellaneous information about
    garbage collection for this process. The content of [;;4mGCInfo[0m
    can be changed without prior notice.

  [;;4m[;;4m{garbage_collection_info, GCInfo}[0m[0m:
    [;;4mGCInfo[0m is a list containing miscellaneous detailed
    information about garbage collection for this process. The
    content of [;;4mGCInfo[0m can be changed without prior notice. For
    details about the meaning of each item, see [;;4mgc_minor_start[0m
    in [;;4merlang:trace/3[0m.

  [;;4m[;;4m{group_leader, GroupLeader}[0m[0m:
    [;;4mGroupLeader[0m is the group leader for the I/O of the process.

  [;;4m[;;4m{heap_size, Size}[0m[0m:
    [;;4mSize[0m is the size in words of the youngest heap generation of
    the process. This generation includes the process stack. This
    information is highly implementation-dependent, and can change
    if the implementation changes.

  [;;4m[;;4m{initial_call, {Module, Function, Arity}}[0m[0m:
    [;;4mModule[0m, [;;4mFunction[0m, [;;4mArity[0m is the initial function call with
    which the process was spawned.

  [;;4m[;;4m{links, PidsAndPorts}[0m[0m:
    [;;4mPidsAndPorts[0m is a list of process identifiers and port
    identifiers, with processes or ports to which the process has
    a link.

  [;;4m[;;4m{last_calls, false|Calls}[0m[0m:
    The value is [;;4mfalse[0m if call saving is not active for the
    process (see [;;4mprocess_flag/3[0m). If call saving is active, a
    list is returned, in which the last element is the most recent
    called.

  [;;4m[;;4m{memory, Size}[0m[0m:
    [;;4mSize[0m is the size in bytes of the process. This includes call
    stack, heap, and internal structures.

  [;;4m[;;4m{message_queue_len, MessageQueueLen}[0m[0m:
    [;;4mMessageQueueLen[0m is the number of messages currently in the
    message queue of the process. This is the length of the list [;;4m[0m
    [;;4mMessageQueue[0m returned as the information item [;;4mmessages[0m (see
    below).

  [;;4m[;;4m{messages, MessageQueue}[0m[0m:
    [;;4mMessageQueue[0m is a list of the messages to the process, which
    have not yet been processed.

  [;;4m[;;4m{min_heap_size, MinHeapSize}[0m[0m:
    [;;4mMinHeapSize[0m is the minimum heap size for the process.

  [;;4m[;;4m{min_bin_vheap_size, MinBinVHeapSize}[0m[0m:
    [;;4mMinBinVHeapSize[0m is the minimum binary virtual heap size for
    the process.

  [;;4m[;;4m{monitored_by, MonitoredBy}[0m[0m:
    A list of identifiers for all the processes, ports and NIF
    resources, that are monitoring the process.

  [;;4m[;;4m{monitors, Monitors}[0m[0m:
    A list of monitors (started by [;;4mmonitor/2[0m) that are active
    for the process. For a local process monitor or a remote
    process monitor by a process identifier, the list consists of:

    [;;4m[;;4m{process, Pid}[0m[0m:
      Process is monitored by pid.

    [;;4m[;;4m{process, {RegName, Node}}[0m[0m:
      Local or remote process is monitored by name.

    [;;4m[;;4m{port, PortId}[0m[0m:
      Local port is monitored by port id.

    [;;4m[;;4m{port, {RegName, Node}}[0m[0m:
      Local port is monitored by name. Please note, that remote
      port monitors are not supported, so [;;4mNode[0m will always be
      the local node name.

  [;;4m[;;4m{message_queue_data, MQD}[0m[0m:
    Returns the current state of process flag [;;4mmessage_queue_data[0m. [;;4m[0m
    [;;4mMQD[0m is either [;;4moff_heap[0m or [;;4mon_heap[0m. For more information,
    see the documentation of [;;4mprocess_flag(message_queue_data,[0m
    [;;4mMQD)[0m.

  [;;4m[;;4m{priority, Level}[0m[0m:
    [;;4mLevel[0m is the current priority level for the process. For more
    information on priorities, see [;;4mprocess_flag(priority, Level)[0m.

  [;;4m[;;4m{reductions, Number}[0m[0m:
    [;;4mNumber[0m is the number of reductions executed by the process.

  [;;4m[;;4m{registered_name, Atom}[0m[0m:
    [;;4mAtom[0m is the registered process name. If the process has no
    registered name, this tuple is not present in the list.

  [;;4m[;;4m{sequential_trace_token, [] | SequentialTraceToken}[0m[0m:
    [;;4mSequentialTraceToken[0m is the sequential trace token for the
    process. This [;;4mInfoTuple[0m can be changed or removed without
    prior notice.

  [;;4m[;;4m{stack_size, Size}[0m[0m:
    [;;4mSize[0m is the stack size, in words, of the process.

  [;;4m[;;4m{status, Status}[0m[0m:
    [;;4mStatus[0m is the status of the process and is one of the
    following:

     • [;;4mexiting[0m

     • [;;4mgarbage_collecting[0m

     • [;;4mwaiting[0m (for a message)

     • [;;4mrunning[0m

     • [;;4mrunnable[0m (ready to run, but another process is running)

     • [;;4msuspended[0m (suspended on a "busy" port or by the BIF [;;4m[0m
       [;;4merlang:suspend_process/1,2[0m)

  [;;4m[;;4m{suspending, SuspendeeList}[0m[0m:
    [;;4mSuspendeeList[0m is a list of [;;4m{Suspendee, ActiveSuspendCount,[0m
    [;;4mOutstandingSuspendCount}[0m tuples. [;;4mSuspendee[0m is the process
    identifier of a process that has been, or is to be, suspended
    by the process identified by [;;4mPid[0m through the BIF [;;4m[0m
    [;;4merlang:suspend_process/2[0m or [;;4merlang:suspend_process/1[0m.

    [;;4mActiveSuspendCount[0m is the number of times [;;4mSuspendee[0m has
    been suspended by [;;4mPid[0m. [;;4mOutstandingSuspendCount[0m is the
    number of not yet completed suspend requests sent by [;;4mPid[0m,
    that is:

     • If [;;4mActiveSuspendCount =/= 0[0m, [;;4mSuspendee[0m is currently
       in the suspended state.

     • If [;;4mOutstandingSuspendCount =/= 0[0m, option [;;4masynchronous[0m
       of [;;4merlang:suspend_process/2[0m has been used and the
       suspendee has not yet been suspended by [;;4mPid[0m.

    Notice that [;;4mActiveSuspendCount[0m and [;;4mOutstandingSuspendCount[0m
    are not the total suspend count on [;;4mSuspendee[0m, only the parts
    contributed by [;;4mPid[0m.

  [;;4m[;;4m{total_heap_size, Size}[0m[0m:
    [;;4mSize[0m is the total size, in words, of all heap fragments of
    the process. This includes the process stack and any
    unreceived messages that are considered to be part of the
    heap.

  [;;4m[;;4m{trace, InternalTraceFlags}[0m[0m:
    [;;4mInternalTraceFlags[0m is an integer representing the internal
    trace flag for this process. This [;;4mInfoTuple[0m can be changed
    or removed without prior notice.

  [;;4m[;;4m{trap_exit, Boolean}[0m[0m:
    [;;4mBoolean[0m is [;;4mtrue[0m if the process is trapping exits, otherwise [;;4m[0m
    [;;4mfalse[0m.

  Notice that not all implementations support all these [;;4mItem[0ms.

  Failures:

  [;;4m[;;4mbadarg[0m[0m:
    If [;;4mPid[0m is not a local process.

  [;;4m[;;4mbadarg[0m[0m:
    If [;;4mItem[0m is an invalid item.
