A tree contains node definitions which can be laid out in a semantic way.

This means, using indentation and the fluent notation, it is possible to

reflect the real structure of the configuration values::

reflect the real structure of the configuration values:

$rootNode

->children()

* scalar

* boolean

* array

* enum (new in 2.1)

* integer (new in 2.2)

* float (new in 2.2)

* variable (no validation)

and are created with ``node($name, $type)`` or their associated shortcut

``xxxxNode($name)`` method.

Numeric node constraints

..versionadded::2.2

The numeric (float and integer) nodes are new in 2.2

Numeric node (float and integer) provide two extra constraints min() and max() allowing to validate the value:

..code-block::php

Array nodes