Give NamedArgumentList’s { a preIndent

[lucaswerkmeister]

Formatter currently turns

1->"".join
    { for (value i in 1..spacesPerLevel) " " } // todo: check speed of " ".join("", "", ...) vs "".join(" ", " ", ...)

into

1->"".join
{ for (value i in 1..spacesPerLevel) " " } // todo: check speed of " ".join("", "", ...) vs "".join(" ", " ", ...)

[lucaswerkmeister]

Reverted by 20ec4bd32aae293ceb7ab0be1d0b08eceeae2971. Now that I see the above code, it’s doesn’t seem so stupid anymore… I’ll need to figure out something smarter.

[lucaswerkmeister]

Okay, so here’s something that I hope is smarter:

• If there are named arguments, the opening brace has no indentBefore, and may follow 0 or 1 line breaks: You may write either

  Html {
    doctype = html5;
    Head { title = "Ceylon home page"; };
    Body {
        H2("Welcome to Ceylon!")
    };
  }

  or

  Html
  {
    doctype = html5;
    Head { title = "Ceylon home page"; };
    Body
    {
        H2("Welcome to Ceylon!")
    };
  }

  Note the inline Head! We still want to allow that – even with multiple short arguments it can look good – so we won’t enforce line breaks between named arguments, or before the opening brace. (We may later add an option to disallow the { on a new line, though.)

• If there are no named arguments, but a nonempty sequential argument, the opening brace gets an indentBefore of 1:

  sum
    { -1.0, for (i in 0..10) 1.0/2^i }

  A named argument list with only sequenced arguments looks exactly like an iterable literal, so we encourage it to be in one separate line. This can result in the unfortunate case of

  sum
    { for (i in 1:100)
    if (i % 2 == 0)
        i }

  where the if clause looks like it hasn’t gained any indentation, but I don’t see how we can do even better than that.

• If there are no named arguments and the sequential argument is empty, the opening brace may not be on a new line, and may not be followed by a line break either.

[lucaswerkmeister]

Formatter output:

Body
    {
    H2("Welcome to Ceylon!")
};

There are fully hierarchic forms composed exclusively of sequenced arguments. Dang.

[lucaswerkmeister]

So without peeking at the original line breaks (which I don’t want to do… it’s difficult to define an API for it, and it doesn’t work if we don’t have the original tokens), we simply cannot distinguish between

Body
{
    H2("Welcome to Ceylon!"),
    P("Now get your code on! \{SMILING FACE WITH SMILING EYES}")
}

and

sum
    { -1.0, for (i in 0:10) 1.0 / 2^i }

For now I’ll restore the previous state with indentBefore 1 (favors sum). I’ll add an option later to change that to 0 (favors Body).

[lucaswerkmeister]

Reopening and moving to next milestone for additional option.

[lucaswerkmeister]

By the way, a multi-line sum is actually nicely formatted as

sum
    { for (i in 1:100)
        if (i % 2 == 0)
            i };

because of the indentation of the opening brace, which still applies.

[gavinking]

Oh that is nice.

Sent from my iPhone

On 29 Sep 2014, at 8:23 pm, Lucas Werkmeister notifications@github.com wrote:

By the way, a multi-line sum is actually nicely formatted as

sum { for (i in 1:100) if (i % 2 == 0) i }; because of the indentation of the opening brace, which still applies.

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