Monte-Carlo methods are known to intensively create nodes and in our
case each leaf of the tree stores a board. However, for this use case,
we don't need a full board object that also contains game information.
This patch adds a `clone_cleared()` method that return a clone without
game information and uses it when constructing the tree.
It allows the ChessEngine much more possibility before getting out of
memory.
The hash function should take the board by reference, not by value.
Also, the fact whether black can castle kingside or not was included
twice in the hash, unnecesarily.
Make everything signed so that we don't have to deal with silly casting
issues thoughout the Chess code. I am unsure if this affects the chess
AI negatively, it seems just as "intelligent" before and after this
change :^)
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
This is basically just for consistency, it's quite strange to see
multiple AK container types next to each other, some with and some
without the namespace prefix - we're 'using AK::Foo;' a lot and should
leverage that. :^)
