Make indentation more intuitive

[Aunmag]

It would be cool if this template might produce something like:

@()
begin
@for n in &vec![0, 1, 2] {
  @if true {
  test
  }
}
end

begin
  test
  test
  test
end

But to get the same output I have to write the template in this way, and it looks kinda dirty:

@()
begin@for n in &vec![0, 1, 2] {@if true {
  test}}
end

So the point is: if a line contains only start or end of an expression, and while spaces or tabs or line-break, then it will be skipped. It will allow to write more readable and intuitive templates.

More examples:

• See the template written with Rocker Java library: https://gist.github.com/Aunmag/1a2424f853e7d47b10c726a78a480119
• See the same template written with ructe https://gist.github.com/Aunmag/6737e50815ed10832e8790d6ee6e3aa4

The first one looks better, doesn't it? :)

I hope you will take more attention to Rocker developer's experience, 'cause we need such a great tool in Rust too.

[Aunmag]

Probably this issue intersects with https://github.com/kaj/ructe/issues/29

[kaj]

After some experimentation, I have more or less decided against the solution I suggsted in #29, and in favor of something like https://github.com/kaj/ructe/pull/42#issuecomment-510231217 . That would hopefully make it possilble to get your expected output by adding a backslash at the end of selected lines of the template.

Do you think that would suffice?

[Aunmag]

I'm not sure how it would look like. Like this?

@()
begin\
@for n in &vec![0, 1, 2] {\
@if true {
  test\
}}
end

Personally, this approach is not clean enough for me. Maybe I miss something.

[kaj]

Yes, something like that.

Your idea of not generating output for template lines that is only statements would be nice, but a bit harder to implement. Ructe does not look at a template line by line, but would instead have to look at the end of the last thing before a block-opening statement and compare it to the first thing in the block, and similiar for the end of the block (and a special case for "else" blocks).

But I'll keep this issue open and think about it. PR:s welcome, of course.