Subject: 26.1; ada-mode 6.0.0 indentation of operators starting a line in a multi-line expression

From: Ludovic Brenta <[email-masked]>
Date: Fri, 14 Dec 2018 16:57:17 +0100

Package: emacs, ada-mode
X-Debbug-CC: [email-masked]

Hello, consider the line marked "incorrectly indented" below:

procedure Operator_Indentation is
begin
   if B
        or else C
        > 2 -- incorrectly indented
   then
     null;
   end if;
end Operator_Indentation;

We think the indentation performed by ada-mode 6.0.0 is incorrect.
Of course we understand that the line is indented relative to B
but as this line is part of a sub-expression, we think it should be
indented relative to the sub-expression instead.  We cannot decide
which of the two following alternatives is the most "correct":

procedure Operator_Indentation is
begin
   if B
        or else C
          > 2 -- indented relative to "or else"
   then
     null;
   end if;
end Operator_Indentation;

procedure Operator_Indentation is
begin
   if B
        or else C
                  > 2 -- indented relative to C, which starts the 
sub-expression
   then
     null;
   end if;
end Operator_Indentation;

(we set ada-indent to 2).

Of course, these examples are overly simplified; in our real code base,
we don't write our operators on a separate line unless the previous line
("C" in these examples) is very long.  To illustrate this, our actual 
code
looks more like:

procedure Operator_Indentation is
begin
   if Blarg_Meets_Preconditions_For_Subsequent_Test (Blarg)
        or else Critical_Cruising_Configuration_Condition_Code 
(Blarg.Blurp)
          > 2
   then
     null;
   end if;
end Operator_Indentation;

PS. The value of ada-indent-hanging-rel-exp has no effect in this
particular case.

-- 
Ludovic Brenta.