Sensible Initialization

[alcides]

GE had a method to expand the tree, based on a particular depth. Check if it is missing. If it is, bring it back.

[alcides]

This exists via RampedH&H.

However, RH&H passes a max_depth, which is not being respected.

[alcides]

Reproducer in #405.

RampedHalfAndHalfInitializer(max_depth=3) on a tiny recursive grammar (Expr → Leaf | Branch(Expr, Expr)), seed NativeRandomSource(5), population 20, produced depths:

[9, 3, 3, 3, 4, 1, 1, 1, 1, 1, 1, 1, 5, 2, 1, 1, 1, 1, 6, 5]

5 of 20 trees exceed the limit (worst is 9). max_depth is stored on the initializer but never passed into create_genotype(), so the representation's default decider is used instead.

Test (xfail until this is fixed): tests/representations/tree_based/initializer_test.py::TestInitializers::test_ramped_half_and_half_respects_max_depth