lisp典型缩进约定背后的规则是什么?

mods注意:请注意,这个问题根本不是品味的问题。我想了解有关我在Spacemacs的elisp默认缩进规则中遇到的缩进约定的具体信息。

为什么格式化程序会这样缩进此代码:

(defun lispy--maybe-safe-delete-region (beg end)
  "Delete the region from BEG to END.
If `lispy-safe-delete' is non-nil, exclude unmatched delimiters."
  (if lispy-safe-delete
      (let ((safe-regions (lispy--find-safe-regions beg end)))
        (dolist (safe-region safe-regions)
          (delete-region (car safe-region) (cdr safe-region)))
        (test))
    (delete-region beg end)
    (test)))

而不是这样:

(defun lispy--maybe-safe-delete-region (beg end)
  "Delete the region from BEG to END.
If `lispy-safe-delete' is non-nil, exclude unmatched delimiters."
  (if lispy-safe-delete
      (let ((safe-regions (lispy--find-safe-regions beg end)))
        (dolist (safe-region safe-regions)
          (delete-region (car safe-region) (cdr safe-region)))
        (test))
      (delete-region beg end)
      (test)))

如您所见,默认格式没有缩进 if 同一级别的sexp。我不理解它的运作规则,因为 let sexp在同一级别缩进。