supertype in subtype

[ytanimura]

Close #126

[ytanimura]

Summary of changes

• Adds supertype into subtype as a field.

pub struct Cat {
    pub pet: Pet,
    pub tail_color: String,
}

• Adds table both of SuperType and SuperTypeAny.

pub struct Tables {
    pet: HashMap<u64, as_holder!(Pet)>,
    pet_any: HashMap<u64, as_holder!(PetAny)>,
    cat: HashMap<u64, as_holder!(Cat)>,
}

The secondary change perhaps superfluity...

Original EXPRESS for example:

SCHEMA pets;

ENTITY pet;
	name: STRING;
END_ENTITY;

ENTITY cat SUBTYPE OF (pet);
	tail_color: STRING;
END_ENTITY;

END_SCHEMA;

[termoshtt]

Adds table both of SuperType and SuperTypeAny.

This should not be added. In original design, impl EntityTable<XxxAny> for Tables { ... } should be used to get owned XxxAny type from Tables.

This impl will be generated by ruststep_derive::select::Input::impl_entity_table, but it seems ruststep::ap201 lacks it (this must be a bug).

[termoshtt]

This impl will be generated by ruststep_derive::select::Input::impl_entity_table, but it seems ruststep::ap201 lacks it (this must be a bug).

I will fix this in #135. For this PR,

Adds table both of SuperType and SuperTypeAny.

please remove this part, and focus only on the first "Adds supertype into subtype as a field." part.

[ytanimura]

It has been modified to conform to the source code https://github.com/ricosjp/ruststep/blob/master/ruststep/tests/any_deserialize.rs .

[ytanimura]

Now, exprc is refactored #165. Rebuilt the pull request #166 again.