haskell - 使用四叉树表示 2^nx 2^n 矩阵时

Question

我刚刚在教科书上找到了定义，无法想象nexp应该做什么/意味着什么：

data (Eq a, Show a) => QT a = C a | Q (QT a) (QT a) (QT a) (QT a)
    deriving (Eq, Show)

data (Eq a, Num a, Show a) => Mat a = Mat {
    nexp :: Int,
    mat :: QT a}
    deriving (Eq,Show)

目的是nexp :: Int什么？

Answer 1

My best guess is that nexp is just the n used in the exp-onent to define how large the matrix is (2^n x 2^n).