Basic implementation of Marshal.load and Marshal.dump.

[iliabylich]

Things that has been changed to make Marshal working:

• Array#instance_variables doesn't return indexes
• Module#instance_variables doesn't return constants
• String subclasses do not return @literal in ivars list.

Limitations:

• Marshal.dump(:symbol) - no Symbols support
• String encoding - dumping/loading a string with custom encoding always dumps/loads utf-16 encoded string
• Everything about String mutating - extended strings, ivars on strings and so on.
• Bignum's can't be encoded/decoded

218 examples from rubyspec are passing (Marshal#restore is an alias to Marshal#load, so probably even 300), ~50 are failing.

[iliabylich]

@elia I know in MRI Marshal is a part of corelib. What do you think about moving it to stdlib for Opal? Then it will not change the size of opal/base or opal/mini

[elia]

@iliabylich this what I was thinking, let me know your considerations, I was pondering whether to introduce an opal/full and slim down the default opal including in it the things that are useful in the browser for most of the time, that way we can both 1. keep its size in check and 2. freely implement cool stuff like marshalling without fearing for the size (it's just a require "corelib/THING" away for those ho need it).

Just as a note I'll add that MRuby goes even further including in its basic bundle a dumbed down version of many methods (e.g. gsub can't accept a block and stuff like that). I think in our case it would make the core lib more fragile, but it's still a solution to keep in mind.

cc @meh

[eregon]

FWIW, I fixed mspec upstream in ruby/mspec@203ec67.

[iliabylich]

@eregon Thank you so much! I was going to open a PR to mspec but for some reason I thought that it will not be be accepted 😄

[eregon]

@iliabylich @elia @vais Anything that makes mspec simpler is good and a welcome change!

[iliabylich]

@eregon Thanks, pulling udpates!
@elia I'll try to rebase it to the latest master (if it's possible 😄). Just a final question, are you ok with excluding marshal stuff from opal/opal and forcing everyine to require 'corelib/marshal' manually?

[elia]

@iliabylich I am, let's also add an opal/full

[coveralls]

Coverage decreased (-0.09%) to 87.583% when pulling 8c05d1d on iliabylich:marshal-dump-load-restore-implementation-attempt into 3ee438a on opal:master.

[coveralls]

Coverage decreased (-0.09%) to 87.583% when pulling ba9f740 on iliabylich:marshal-dump-load-restore-implementation-attempt into 3ee438a on opal:master.

[iliabylich]

Done

[elia]

w00t!