Builder objects

[parrish]

Allows schemas to be built iteratively for #4:

obj = object
obj.string :name

Also allows schema entities to reopen and modify children with extend(name):

obj = object do
  object :an_object do
    string :name
  end
end

obj.extend(:an_object) do
  string :another_name
end

# an_object is now {properties: {name: {type: "string"}, another_name: {type: "string"}}}

To replace a child entity, just redefine it:

obj = object do
  object :an_object do
    string :name
  end
end

obj.object :an_object do
  string :replacement_name
end

# an_object is now only {properties: {replacement_name: {type: "string"}}}

[Haniyya]

@parrish I think it would be useful to extract this into its own method.

object_with_child.child(:type) #=> ObjectBuilder<:type> 

Not sure about the name yet, but this way you could pass children easily to other functions as well.

[Haniyya]

Maybe it would be enough to just return the child from extend if !block_given?

[Haniyya]

Otherwise this looks really good. And it's nice that the actual changes are so small. 👍

[parrish]

@Haniyya extend also returns the child now. Released in v0.8.0