Implement record patches feature

[brusherru]

There is no issue. 🙈

However, this feature makes it possible to create C++ structs using types of input terminals and unpack node by adding a record marker on the patch.

How to use:

• create a new patch (named foo for example)
• place some inputs (generics and pulses are prohibited)
• place output-self
• place record marker node

It automatically creates a C++ implementation and the unpack-foo patch.

Also, some custom types might be easily replaced with this thing.

[nkrkv]

Massive 👍

The one thing I miss from this PR is an end-to-end test fixture that would show the real C++ code generated for records pack/unpack.

[brusherru]

I've added abstract xod/json/to-json node and specializations to the primitive types in the same library. And made an auto-creation of specialization for the record. So records might be easily serialized to JSON.
Check it out, please.
@nkrkv @evgenykochetkov

[brusherru]

@nkrkv @evgenykochetkov it's done to review!
Last changes:

1. I fixed my own bug in the transpilation (last fixup)
2. I made record fields named with pin labels instead of index.

[nkrkv]

You haven’t updated a fixture workspace/record-pack-unpack/__fixtures__/arduino.cpp. It still defines the struct as:

    struct Type {
        static constexpr typeof_PORT _0 = constant_input_PORT;
        typeof_N _1;
        typeof_STR _2;
        typeof_AREC _3;
    };

It’s a problem (1). The CCI server gave no error because of this, it’s a problem (2).

[evgenykochetkov]

IMHO, the error message seems a bit unclear. I think it should mention output-self node.

[evgenykochetkov]

[evgenykochetkov]

/ws/sketchbook/be1830b1f421f4c8fa703a23a859de0cc02ba339c8743ce339975ba147933f47/sketch/sketch.ino:1487:72: error: no member named 'field_IN' in 'xod::____bar::Node<'\x0D'>::Type'
        static constexpr typeof_OUT2 constant_output_OUT2 = typeof_IN::field_IN;
                                                            ~~~~~~~~~~~^
/ws/sketchbook/be1830b1f421f4c8fa703a23a859de0cc02ba339c8743ce339975ba147933f47/sketch/sketch.ino:2002:17: note: in instantiation of template class 'xod::____unpack_bar::Node<xod::____bar::Node<'\x0D'>::Type>' requested here
Node_9 node_9 = Node_9({ /* @/foo */ });
                ^
/ws/sketchbook/be1830b1f421f4c8fa703a23a859de0cc02ba339c8743ce339975ba147933f47/sketch/sketch.ino:2014:19: error: cannot convert 'xod::XString' (aka 'List<char>') to 'xod::Node_13' (aka 'int') without a conversion operator
Node_13 node_13 = Node_13(XString());
                  ^~~~~~~~~~~~~~~~~
/ws/sketchbook/be1830b1f421f4c8fa703a23a859de0cc02ba339c8743ce339975ba147933f47/sketch/sketch.ino:2317:13: error: 'xod::Node_13' (aka 'int') is not a class, namespace, or enumeration
            Node_13::ContextObject ctxObj;
            ^
/ws/sketchbook/be1830b1f421f4c8fa703a23a859de0cc02ba339c8743ce339975ba147933f47/sketch/sketch.ino:2324:20: error: member reference base type 'xod::Node_13' (aka 'int') is not a structure or union
            node_13.evaluate(&ctxObj);
            ~~~~~~~^~~~~~~~~
/ws/sketchbook/be1830b1f421f4c8fa703a23a859de0cc02ba339c8743ce339975ba147933f47/sketch/sketch.ino:2414:39: error: member reference base type 'xod::Node_13' (aka 'int') is not a structure or union
            ctxObj._input_IN = node_13._output_OUT;
                               ~~~~~~~^~~~~~~~~~~~
5 errors generated.

[brusherru]

@evgenykochetkov just pushed two fixups with a tweaked error message and fix for constants.

[evgenykochetkov]

LGTM!