Std.Tree.Tree

type

This declaration introduces a public type.

What it does

A value with a sequence of trees beneath it.

A syntax tree, an outline, a menu, a reporting line, a dependency view: each

is one thing that holds a number of things of the same kind. Written out

each time, that is a record and a handful of walks, rewritten per program

and subtly different in each — one counts the root, another does not; one

keeps the order children were given, another sorts them.

The shape here settles those questions once. Every node carries a value and

a sequence of children, and a node with no children is not a separate case:

it is a node whose sequence is empty. That is what removes the Option a

hand-written hierarchy usually has at every branch.

Children keep the order they were given. A hierarchy where order did not

matter would be a node holding a Set, and that is a different structure

with a different type.

Read the signature

• This declaration has no value signature because it introduces a type or trait.