Add docstrings for class/actor members

[mfelsche]

Optionally allow docstrings for class/actor fields below or above the field definition.

class MyClass
  """class docstring"""

  let number: U32 = 1
  """field docstring below"""
  
  fun method(arg: String): None =>
    """method docstring"""
    None

class MyClass
  """class docstring"""

  """field docstring above"""
  let another_number: U32 = 1
  
  fun method(arg: String): None =>
    """method docstring"""
    None

I would like your opinion on this. Maybe a kind of a vote, No, Above or Below?

[Theodus]

I prefer the first option

[jemc]

The second option has potential to have confusing edge cases when you didn't include class/actor-level docs.

I'm not opposed to the first option, and I do think it's parseable in theory.

[SeanTAllen]

Definitely the first. The 2nd is confusing.

[mfelsche]

I also thought putting it right after the type and before the optional assignment but this resulted in much more confusing code imo.

Just for demonstration purposes:

let field: String """docstring""" = "value"

let another_field: U8
"""
docstring
"""
= 0

[mfelsche]

I am nonetheless also open for the solution of the docstring right after the type and before the optional assignment. If this is what you prefer.

[peterzandbergen]

In the go language all documentation is before the item being documented.

What I know about docstring is that it is after the item, so I'd opt for the first option, more consistent so less to remember.