Semantic Line Breaks

I don't get it.

TBH most of the time I find markdown's collapsing of whitespace annoying - if you want a 'visual' line-break you have to add unnatural double space at the end of preceding line. And even this is renderer dependent, I don't think is part of the spec (?) so some renderers don't respect it (and IIRC GitHub comments renderer does't need it, i.e. doesn't do semantic line breaks)

Another pet hate is text editors which auto-convert double space into ". " - I find this even cropping up in IDEs now, so you try to add an end of line comment "...] # here" and it turns into "...]. # here". Awful

> Without any line breaks at all, this paragraph appears in source as a long, continuous line of text

Of course it doesn't because

> (which may be automatically wrapped at a fixed column length, depending on your editor settings):

Indeed, are you short on apps that support this ancient text formatting feature?

> Adding a line break after each sentence makes it easier to understand the shape and structure of the source text

Nope again, visually you've just wasted my devices width or overestimated my smartphone's width and I get exactly the same issue you've just complained about: a single sentence that doesn't fit.

Semantically, what you're looking for already exists and is called a paragraph. A sentence has a different meaning, which you break by line breaking after every single one. It kills the structure, not "makes it easier to understand the shape and structure of the source text" (also, bullet points exist)

PS By the way, why deprive readers of extra clarity offered by this formatting?

> We can further clarify the source text by adding a line break after the clause “with reason and conscience”. This helps to distinguish between the “and” used as a coordinating conjunction between “reason and conscience” and the “and” used as a subordinating conjunction with the clause

There is a very good technical argument for NOT using "semantic" line breaks when editing markup source code, especially of the "hardwrap" variety, and that is the ability to easily diff two versions of the same document, e.g. when comparing latex git commits.

Anything that reorganises the sentence around for the sake of maintaining justification, completely destroys any meaningful diff from taking place.

And ideally your editor should support both hard and soft wrapping, so that aesthetics of wrapping shouldn't be a big issue.

And I say this as a fan of hardwrapping text.

Prior art on writing line oriented prose comes from one B. Kernighan, no less! Via this blog post:

https://rhodesmill.org/brandon/2012/one-sentence-per-line/

> Start each sentence on a new line. Make lines short, and break lines at natural places, such as after commas and semicolons, rather than randomly. Since most people change documents by rewriting phrases and adding, deleting and rearranging sentences, these precautions simplify any editing you have to do later.

— Brian Kernighan, 1974

> A semantic line break SHOULD occur after an […] em dash (—).

I agree with this, however it means that no existing markup language supports semantic line breaks, because every last one of them just turns the break into a space—and em dashes are, in most locales, not to be surrounded by a space. Consequently, you’ll end up with a stray space if you do this.

My irritation at being unable to break after an em dash (which I want to do quite frequently) was one of the things that headed me down the path of designing my own lightweight markup language (LML), to fix this and other problems I observe with existing LMLs. I’ve been using it for all my personal writing for something like four years now (though a a fair bit has changed since then), and I expect to finally have a functioning parser before the end of this year.

One of the other fun complications of this kind of line break in source code is languages that don’t have a word divider—inserting a space at all is incorrect in them.

CSS presently just leaves such decisions UA-defined <https://drafts.csswg.org/css-text-4/#line-break-transform>:

> any remaining segment break is either transformed into a space (U+0020) or removed depending on the context before and after the break. The rules for this operation are UA-defined in this level.

My LML currently turns segment breaks into a space unless the line ends with an en or em dash, unless there’s a colon or a space before that. I haven’t got anything in place for languages with no word separator yet, but it is unusually well-suited to such languages.

this seems to consider "text being read after formatting" and "text being read before formatting" as different things.

Which I guess, if you're the sole author of the text might be true.

But in my experience most text that gets rendered is also read and edited by multiple people in its source form, so why wouldn't you want to make source just as easy to read?

The problem is that this makes having line breaks that are not paragraph breaks in the output much more awkward and I think those are much more important than line breaks that are only there in the source.

This is especially true for Markdown which is supposed to be a pretty rendering of conventions that were already common in text only communication so it's weird when explicitly entered line breaks are ignored in the output.

i thought this was for ruby and javascript and this would be really cool.

automated formatting including newlines, would be great.