[bug] Adjacent Docstrings are not combined across interleaved comments

[JasonLunn]

Given a .bzl that defines a macro like:

def foo(
        name,
        bar,
        baz,
        **kwargs):
    """Does something.

    Args:
      name: Name of the build target.
      bar: Bar.
      baz: Baz.
      **kwargs: Other args to be passed on to genrules.
    """

I expected to be able to leverage implicit concatenation of adjacent strings to split the DocString into multiple chunks with comments interleaved between them: e.g.:

def foo(
        name,
        bar, # strip
        baz, #strip
        **kwargs):
    """Does something.

    Args:
      name: Name of the build target.
    """
    # begin-strip
    """
      bar: Bar.
      baz: Baz.
    """
    # end-strip

   """
      **kwargs: Other args to be passed on to genrules.
   """

[lgalfaso]

Not to have an implicit concatenation was an explicit design decision, so I would expect that this is not going to happen.
Context: https://github.com/bazelbuild/starlark/blob/master/design.md#no-implicit-string-concatenation

[JasonLunn]

Explicit concatenation of DocStrings doesn't work as expected either:

def foo(
        name,
        bar, # strip
        baz, #strip
        **kwargs):
    """Foo
    """ +
    """Bar
    """ +
    """Baz"""

Makes the help text Baz rather than Foo\nBar\nBaz

[lgalfaso]

@JasonLunn do not fully understand your example. The below is an invalid syntax as you cannot have the RHS expression in another line unless you use parentheses (this is the case in Starlark and in Python).

def foo(
        name,
        bar, # strip
        baz, #strip
        **kwargs):
    """Foo
    """ +
    """Bar
    """ +
    """Baz"""

If you add parentheses, then this does what it is expected. eg,

def foo(
        **kwargs):
    print("""Foo
    """ +
    """Bar
    """ +
    """Baz""")

foo()

prints

Foo
    Bar
    Baz

If you would like the string to be Foo\nBar\nBaz, then the same can be accomplished by doing

def foo(
        **kwargs):
    print("""Foo
""" +
    """Bar
""" +
    """Baz""")

foo()

[JasonLunn]

I'm trying to construct Docstring comments though, not arguments to a function.

Wrapping the docstring in parentheses prevents the string from being treated as a docstring:

def foo(
        name,
        bar, # strip
        baz, #strip
        **kwargs):
    ("""Foo
    """ +
    """Bar
    """ +
    """Baz""")

Makes the help text empty, as does trying to fit it all on one line:

def foo(
        name,
        bar, # strip
        baz, #strip
        **kwargs):
    """Foo""" + """Bar""" + """BAZ"""