See also https://bugs.erlang.org/browse/ERL-953.

* hasse/dialyzer/prettier_warnings/OTP-15135:
  dialyzer: Remove quotes around operators
  dialyzer: Add test cases with indentation
  dialyzer: Add an --no_indentation option
  dialyzer: Add parentheses around annotated union elements
  dialyzer: Fix dialyzer_dataflow:format_args_1()

A smallish selection of already existing tests, run with
the indentation option.

By default Dialyzer tries to improve the readability of warnings.
Newlines are inserted before and inside types, signatures, and Erlang
code. Sometimes the newlines look misplaced. The raw format
(option --raw) is not affected.

Use the new --no_indentation option get the old behavior (no inserted
line breaks).

A note on the implementation. The types &c present in the warning
tuples are parsed, and then formatted using erl_pp, the Erlang Pretty
Printer. The alternative, to create message tuples with formatted
types, turned out to more complicated, and has no real benefits.

Also notice that the fixes for binaries (commit 9db8a098) and union
elements (commit a1e51d12) are required. As a consequence, messages
created before these commits using the --raw option cannot always be
indented.

See also https://bugs.erlang.org/browse/ERL-845.

[Kostis:]

My suggestion is that the compiler refuses to compile modules that
contain specs for functions that are not from this module. I do not
remember when / why this `feature' was introduced, but thinking about
it I see a lot of (ugly) semantics issues with it. For example, should
one be allowed to declare in the foo module that lists:flatten/1 takes
an integer() as an argument and returns a binary()? Should one be
allowed to declare a spec in some module m1 for a function of m2 that
is not defined in m2?

There are all kinds of checks that will need to be added to dialyzer
to protect itself from these semantics issues. The compiler already
refuses to compile modules that contain specs for non-existing
functions of the module. Similarly, it should refuse to compile
modules that contain specs for functions of other modules - unless it
can somehow check that these functions are indeed defined, but it is
not how the compiler currently works.

In contracts, annotated elements of unions are printed with
parentheses around them. They are not parseable otherwise.

The mismatching argument positions are included.

* hasse/dialyzer/improve_binary_printing/OTP-15752:
  dialyzer: Fix pretty printing of binaries