This formatting scheme is more appropriate if you think of chaining multiple
infix expressions and combining it with do-blocks. The operator should hang
on previous line instead going first on the next line, e.g.:
foo +
bar
instead of
foo
+ bar
The main point of this commit is perhaps that certain constructions are rare
and unnatural in multi-line form, so we could print them always in
single-line form however putting parentheses still in multi-line fashion so
the properly of idempotency is satisfied.
This pull request implements most of currently missing types of expressions,
with the exception of:
* Do notation
* List comprehensions (list comprehensions are considered a kind of do
notation in GHC)
* Arrow notation
* Template Haskell
Most expressions are pretty printed in an uncontroversial manner, preferably
similar to existing syntax.
