Code style: separate parts of If statement

[maxitg]

The problem

The issue with If in Wolfram Language is that it's very easy to miss the difference between a compound expression and an "else". That is, compare

If[x > 0,
  a = 4;
  b = a + 1
]

to

If[x > 0,
  b = 4,
  b = a + 1
]

Possible solution

To make these cases more readable, the following style is suggested:

If[x > 0,
  b = 4
,
  b = a + 1
]

The idea behind this indentation is that the comma takes the part of an else if in a language like C++:

If[x > 0,
  b = 4
,  (* else *)
  b = a + 1
]

A similar style should be used in other functions where compound expressions are expected. For example, Catch:

Catch[
  Message[abc::def];
  x = 5;
,
  Exit[1]
]

Additional context

This should eventually make its way into linter #247. In the meantime, we need to update the existing code itself and the contributing guidelines.