Change single line let statements

Currently, in do blocks, let statements automatically put the declaration on the next line. for example:

do
  thing1 <- foo x
  let thing2 = bar x
  baz thing2

reformats to:

do
  thing1 <- foo x
  let 
    thing2 = bar x
  baz thing2

personally I think it makes a lot more sense to have single line let statements on one line. I've not written a parser before though so I understand if it's not feasible to decide when this is the case (especially for long lines.