Method reduce

packages/muya/src/block/base/parent.ts:162–167

(
        callback: (memo: M, cur: TreeNode, i: number) => M,
        initialValue: M,
    )

    }

    reduce<M>(
        callback: (memo: M, cur: TreeNode, i: number) => M,
        initialValue: M,
    ): M {
        return this.children.reduce<M>(callback, initialValue);
    }

    /**
     * Use the `block` to replace the current block(this)