This creates a smaller state machine helper type for softness coalescing, which does not own the resulting nodes. While this creates a bit more duplication in stack and par builder, it makes it a lot easier to integrate additional logic into the paragraph builder.
Furthermore:
- Line breaks are now "hard", that is, not coalesced with each other.
- Text nodes with equal style are now merged allowing for example `f{}i` to form a ligature.
This adds overridable functions that markup desugars into. Specifically:
- \ desugars into linebreak
- Two newlines desugar into parbreak
- * desugars into strong
- _ desugars into emph
- = .. desugars into heading
- `..` desugars into raw
Adds top-edge and bottom-edge parameters to the font function. These define how
the box around a word is computed. The possible values are:
- ascender
- cap-height (default top edge)
- x-height
- baseline (default bottom edge)
- descender
The defaults are chosen so that it's easy to create good-looking designs with
vertical alignment. Since they are much tighter than what most other software
uses by default, the default leading had to be increased to 50% of the font size
and paragraph spacing to 100% of the font size.
The values cap-height and x-height fall back to ascender in case they are zero
because this value may occur in fonts that don't have glyphs with cap- or
x-height (like Twitter Color Emoji). Since cap-height is the default top edge,
doing no fallback would break things badly.
Removes softness in favor of a simple boolean for pages and a more finegread u8
for spacing. This is needed to make paragraph spacing consume line spacing
created by hard line breaks.
- The execution context is a lot more structured: Instead of a magic stack of arbitrary objects there are static objects for pages, stacks and paragraphs
- Page softness/keeping mechanic is now a lot simpler than before
- Only add line spacing between lines. Previously, line spacing was added below
every line, making `#box[word]` higher than just `word`.
- Compute box height of text as `ascender - descender` so that the full word is
contained in the box.
