Weird multi-line string indentation

[pfitzseb]

julia> print(JuliaFormatter.format_text("""
       write("", \"\"\"
           second
           third
           \"\"\")
       """))
write(
    "",
    """
second
third
""",
)

Not strictly an issue since it parses correctly, but does look weird.

Originally reported at julia-vscode/julia-vscode#2545.

[domluna]

this looks correct to me, if you look at how the text is placed in relation to the opening """ in the original text it's the same in the formatted output. It can lead to weird text in some cases, but you can indent the words more as one 1 way to get around it. This is done intentionally so that strings are left intact.

This nests because the current rule is that if a string is multiline in a function call, the function call is automatically nested.

[pfitzseb]

Well, that's not the invariant I expected :)

write(
    "",
    """
    second
    third
    """,
)

parses the same and looks nicer, imho.

[domluna]

true, would this backfire in other cases though?

[pfitzseb]

Well, Julia disregards

• a leading newline
• the whitespace all lines have in common

Sooo, sure, there are case where indentation isn't possible.

[domluna]

would it be bad to align the lines to the first " if they currently appear prior to it? If it's a good idea it wouldn't be difficult to do (i think)

[mortenpi]

Not 100% sure if it's related, but this

function myfunction_foo(io::IO)
    write(io, """
    """)
end

goes into

function myfunction_foo(io::IO)
    write(
        io,
        """
""",
    )
end

which does seem pretty weird to me.

[domluna]

that's intentional. the distance between the start and end quotes stays consistent.

[mortenpi]

That doesn't seem necessary? The string wouldn't change? So it could just go into

function myfunction_foo(io::IO)
    write(
        io,
        """
        """,
    )
end

Or if we do insist on keeping the distance, then it could go into

function myfunction_foo(io::IO)
    write(
        io,
            """
        """,
    )
end

which would still be a bit weird, but slightly better? Basically, it should be aligning the ending """, not the starting one. There may well be an edge case here that I'm not thinking of right now though.

[pfitzseb]

Yeah, that's not required. Julia doesn't care about leading whitespace common to all lines inside of the string, cf

julia> x = """
       """
""

julia> x = """
           """
""

julia> x = """

           """
"\n"

julia> x = """

       """
"\n"

julia> x = """
           ab
           """
"ab\n"

julia> x = """
           ab
       """
"    ab\n"

julia> x = """
        ab
       """
" ab\n"

[domluna]

julia> x = """
           ab
       """
"    ab\n"

julia> x = """
           ab
        """
"   ab\n"

these are different based on the positioning of the quotations though, which is why it's maintained.

[pfitzseb]

They are only different based on the distance between ab and the closing quotes. The formatter needs to keep the string content the same without taking common leading whitespace into account.

[domluna]

if the other way is more aesthetically pleasing I would be open to it. Not sure when i would get around to doing a PR atm

[pfitzseb]

Imho we should never indent multi-line strings by less than the surrounding code. IIRC CSTParser handles multi-line strings with common leading whitespace fairly well, so maybe it'll be easy to implement this here.

[domluna]

Imho we should never indent multi-line strings by less than the surrounding code. IIRC CSTParser handles multi-line strings with common leading whitespace fairly well, so maybe it'll be easy to implement this here.

makes sense. I'd be assist with a PR.