Goals:
* Make the set of combinators clearer and smaller.
* Solve a number of issues, such as those about parse failures related to
patterns.
* Solve the bug from #244.
The idea is very simple, we stop doing this
( foo
, bar
)
and start doing this
( foo,
bar
)
* We switch to trailing commas which solves the indentation issues for
patterns automatically.
* The new general ‘sep’ combinator finally is clear enough, and all the old
zoo of ‘velt’ and ‘velt'’ and ‘sepWith’, etc. which was confusing and
overlapping goes away.
Certain other kinds of declarations (such as associated type signatures and
bindings) are grouped together without newlines. The process for determining
which declarations are grouped reuses the same logic as for modules.