Convert a readfile()-style list or a Blob to a list of VimL objects. Example:

let fname = expand('~/.config/nvim/shada/main.shada')
let mpack = readfile(fname, 'b')
let shada_objects = msgpackparse(mpack)

This will read ~/.config/nvim/shada/main.shada file to shada_objects list.

Limitations:

1. Mapping ordering is not preserved unless messagepack mapping is dumped using generic mapping (msgpack-special-map).
2. Since the parser aims to preserve all data untouched (except for 1.) some strings are parsed to msgpack-special-dict format which is not convenient to use.

Some messagepack strings may be parsed to special dictionaries. Special dictionaries are dictionaries which

1. Contain exactly two keys: _TYPE and _VAL.
2. _TYPE key is one of the types found in v:msgpack_types variable.
3. Value for _VAL has the following format (Key column contains name of the key from v:msgpack_types):

Key Value nil Zero, ignored when dumping. Not returned by msgpackparse() since v:null was introduced. boolean One or zero. When dumping it is only checked that value is a Number. Not returned by msgpackparse() since v:true and v:false were introduced. integer List with four numbers: sign (-1 or 1), highest two bits, number with bits from 62nd to 31st, lowest 31 bits. I.e. to get actual number one will need to use code like

        _VAL[0] * ((_VAL[1] << 62)
                   & (_VAL[2] << 31)
                   & _VAL[3])

    Special dictionary with this type will appear in
    `msgpackparse()` output under one of the following
    circumstances:
    1. `Number` is 32-bit and value is either above
       INT32_MAX or below INT32_MIN.
    2. `Number` is 64-bit and value is above INT64_MAX. It
       cannot possibly be below INT64_MIN because msgpack
       C parser does not support such values.

float Float. This value cannot possibly appear in msgpackparse() output. string readfile()-style list of strings. This value will appear in msgpackparse() output if string contains zero byte or if string is a mapping key and mapping is being represented as special dictionary for other reasons. binary String, or Blob if binary string contains zero byte. This value cannot appear in msgpackparse() output since blobs were introduced. array List. This value cannot appear in msgpackparse() output.

map List of Lists with two items (key and value) each. This value will appear in msgpackparse() output if parsed mapping contains one of the following keys: 1. Any key that is not a string (including keys which are binary strings). 2. String with NUL byte inside. 3. Duplicate key. 4. Empty key. ext List with two values: first is a signed integer representing extension type. Second is readfile()-style list of strings.