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//! The document model.
mod content;
mod element;
mod introspect;
mod label;
mod realize;
mod selector;
mod styles;
#[doc(inline)]
pub use typst_macros::element;
pub use self::content::{Content, MetaElem, PlainText};
pub use self::element::{Construct, ElemFunc, Element, NativeElemFunc, Set};
pub use self::introspect::{Introspector, Location, Locator};
pub use self::label::{Label, Unlabellable};
pub use self::realize::{
applicable, realize, Behave, Behaviour, Finalize, Guard, Locatable, Show, Synthesize,
};
pub use self::selector::{LocatableSelector, Selector, ShowableSelector};
pub use self::styles::{
Fold, Property, Recipe, Resolve, Style, StyleChain, StyleVec, StyleVecBuilder,
Styles, Transform,
};
use std::mem::ManuallyDrop;
use comemo::{Track, Tracked, TrackedMut, Validate};
use crate::diag::{SourceError, SourceResult};
use crate::doc::Document;
use crate::eval::Tracer;
use crate::World;
/// Typeset content into a fully layouted document.
#[comemo::memoize]
#[tracing::instrument(skip(world, tracer, content))]
pub fn typeset(
world: Tracked<dyn World + '_>,
mut tracer: TrackedMut<Tracer>,
content: &Content,
) -> SourceResult<Document> {
tracing::info!("Starting typesetting");
let library = world.library();
let styles = StyleChain::new(&library.styles);
let mut iter = 0;
let mut document;
let mut delayed;
// We need `ManuallyDrop` until this lands in stable:
// https://github.com/rust-lang/rust/issues/70919
let mut introspector = ManuallyDrop::new(Introspector::new(&[]));
// Relayout until all introspections stabilize.
// If that doesn't happen within five attempts, we give up.
loop {
tracing::info!("Layout iteration {iter}");
delayed = DelayedErrors::default();
let constraint = <Introspector as Validate>::Constraint::new();
let mut locator = Locator::new();
let mut vt = Vt {
world,
tracer: TrackedMut::reborrow_mut(&mut tracer),
locator: &mut locator,
introspector: introspector.track_with(&constraint),
delayed: delayed.track_mut(),
};
// Layout!
let result = (library.items.layout)(&mut vt, content, styles)?;
// Drop the old introspector.
ManuallyDrop::into_inner(introspector);
// Only now assign the document and construct the new introspector.
document = result;
introspector = ManuallyDrop::new(Introspector::new(&document.pages));
iter += 1;
if iter >= 5 || introspector.validate(&constraint) {
break;
}
}
// Drop the introspector.
ManuallyDrop::into_inner(introspector);
// Promote delayed errors.
if !delayed.0.is_empty() {
return Err(Box::new(delayed.0));
}
Ok(document)
}
/// A virtual typesetter.
///
/// Holds the state needed to [typeset] content.
pub struct Vt<'a> {
/// The compilation environment.
pub world: Tracked<'a, dyn World + 'a>,
/// Provides access to information about the document.
pub introspector: Tracked<'a, Introspector>,
/// Provides stable identities to elements.
pub locator: &'a mut Locator<'a>,
/// Delayed errors that do not immediately terminate execution.
pub delayed: TrackedMut<'a, DelayedErrors>,
/// The tracer for inspection of the values an expression produces.
pub tracer: TrackedMut<'a, Tracer>,
}
impl Vt<'_> {
/// Perform a fallible operation that does not immediately terminate further
/// execution. Instead it produces a delayed error that is only promoted to
/// a fatal one if it remains at the end of the introspection loop.
pub fn delayed<F, T>(&mut self, f: F) -> T
where
F: FnOnce(&mut Self) -> SourceResult<T>,
T: Default,
{
match f(self) {
Ok(value) => value,
Err(errors) => {
for error in *errors {
self.delayed.push(error);
}
T::default()
}
}
}
}
/// Holds delayed errors.
#[derive(Default, Clone)]
pub struct DelayedErrors(Vec<SourceError>);
#[comemo::track]
impl DelayedErrors {
/// Push a delayed error.
fn push(&mut self, error: SourceError) {
self.0.push(error);
}
}
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