Instead of separating functionality into layout and library, everything lives in the library now. This way, related things live side by side and there are no duplicate file names in the two directories.
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
- New naming scheme
- TextNode instead of NodeText
- CallExpr instead of ExprCall
- ...
- Less glob imports
- Removes Value::Args variant
- Removes prelude
- Renames Layouted to Fragment
- Moves font into env
- Moves shaping into layout
- Moves frame into separate module
- 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
Doesn't layout contents into a box anymore, instead layouting inline in the parent context. Also makes axis inferring for center alignents smarter (just because I had fun doing it). It's unsure whether we want to keep it because it might be confusing.
- In addition to syntax trees there are now `Value`s, which syntax trees can be evaluated into (e.g. the tree is `5+5` and the value is `10`)
- Parsing is completely pure, function calls are not parsed into nodes, but into simple call expressions, which are resolved later
- Functions aren't dynamic nodes anymore, but simply functions which receive their arguments as a table and the layouting context
- Functions may return any `Value`
- Layouting is powered by functions which return the new `Commands` value, which informs the layouting engine what to do
- When a function returns a non-`Commands` value, the layouter simply dumps the value into the document in monospace
Previously they were passed as strings to the function parser, now they are parsed and then passed as trees to the function. This allows making bodies sugar for a last content argument. While it removes some flexibility allowing function to parse arbitrary syntaxes in their bodies, these can be modelled as (raw) string arguments.
Laurenz