Sugar 🍬

For pedagogical reason, field has been used throught the documentation to reinforce the concepts. However, Treeo has a couple of shortcuts to make it easier and more understandable to define Trees.

normal shortcut
to.field(node=True) to.node()
to.field(node=False) to.static()
to.field(node=True, kind=Kind) Kind.node()
to.field(node=False, kind=Kind) Kind.static()

Based on this, you can take the following code

class Parameter:

class Child(to.Tree):
    a: float = to.field(node=True)
    b: str = to.field(node=False)
    c: float = to.field(node=True, kind=Parameter)
    d: float = to.field(node=False, kind=Parameter)

class Parent(to.Tree):
    child1: Child = to.field(node=True)
    child2: Child = to.field(node=False)
    rest: List[Child] = to.field(node=True)

and simplify it to:

class Parameter(to.KindMixin): pass

class Child(to.Tree):
    a: float = to.node()
    b: str # = to.static(), inferred
    c: float = Parameter.node()
    d: float = Parameter.static()

class Parent(to.Tree):
    child1: Child # = to.node(), inferred
    child2: Child = to.static()
    rest: List[Child] # = to.node(), inferred

The to.KindMixin provides the .field(), .node(), and .static() methods to subtypes, in this case the Parameter class.