following a simple algorithm

(three expressions at-the-start
  two in
  the middle
  many at the end)
(with-indentation (lambda (name)
    always proportional to nesting depth))

it is dead simple: one pattern and a simple indent calculation

it makes it particularly easy to predict where the next line starts

it makes the code look more orderly, the complexity and structure easier to grasp

see (sph lang scm-format) for an automatic formatter

tags: format sph-scheme