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-rw-r--r--src/model/collapse.rs116
1 files changed, 0 insertions, 116 deletions
diff --git a/src/model/collapse.rs b/src/model/collapse.rs
deleted file mode 100644
index f57a3a42..00000000
--- a/src/model/collapse.rs
+++ /dev/null
@@ -1,116 +0,0 @@
-use super::{StyleChain, StyleVec, StyleVecBuilder};
-
-/// A wrapper around a [`StyleVecBuilder`] that allows to collapse items.
-pub(super) struct CollapsingBuilder<'a, T> {
- /// The internal builder.
- builder: StyleVecBuilder<'a, T>,
- /// Staged weak and ignorant items that we can't yet commit to the builder.
- /// The option is `Some(_)` for weak items and `None` for ignorant items.
- staged: Vec<(T, StyleChain<'a>, Option<u8>)>,
- /// What the last non-ignorant item was.
- last: Last,
-}
-
-/// What the last non-ignorant item was.
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-enum Last {
- Weak,
- Destructive,
- Supportive,
-}
-
-impl<'a, T> CollapsingBuilder<'a, T> {
- /// Create a new style-vec builder.
- pub fn new() -> Self {
- Self {
- builder: StyleVecBuilder::new(),
- staged: vec![],
- last: Last::Destructive,
- }
- }
-
- /// Whether the builder is empty.
- pub fn is_empty(&self) -> bool {
- self.builder.is_empty() && self.staged.is_empty()
- }
-
- /// Can only exist when there is at least one supportive item to its left
- /// and to its right, with no destructive items in between. There may be
- /// ignorant items in between in both directions.
- ///
- /// Between weak items, there may be at least one per layer and among the
- /// candidates the strongest one (smallest `weakness`) wins. When tied,
- /// the one that compares larger through `PartialOrd` wins.
- pub fn weak(&mut self, item: T, styles: StyleChain<'a>, weakness: u8)
- where
- T: PartialOrd,
- {
- if self.last == Last::Destructive {
- return;
- }
-
- if self.last == Last::Weak {
- if let Some(i) =
- self.staged.iter().position(|(prev_item, _, prev_weakness)| {
- prev_weakness.map_or(false, |prev_weakness| {
- weakness < prev_weakness
- || (weakness == prev_weakness && item > *prev_item)
- })
- })
- {
- self.staged.remove(i);
- } else {
- return;
- }
- }
-
- self.staged.push((item, styles, Some(weakness)));
- self.last = Last::Weak;
- }
-
- /// Forces nearby weak items to collapse.
- pub fn destructive(&mut self, item: T, styles: StyleChain<'a>) {
- self.flush(false);
- self.builder.push(item, styles);
- self.last = Last::Destructive;
- }
-
- /// Allows nearby weak items to exist.
- pub fn supportive(&mut self, item: T, styles: StyleChain<'a>) {
- self.flush(true);
- self.builder.push(item, styles);
- self.last = Last::Supportive;
- }
-
- /// Has no influence on other items.
- pub fn ignorant(&mut self, item: T, styles: StyleChain<'a>) {
- self.staged.push((item, styles, None));
- }
-
- /// Iterate over the contained items.
- pub fn items(&self) -> impl DoubleEndedIterator<Item = &T> {
- self.builder.items().chain(self.staged.iter().map(|(item, ..)| item))
- }
-
- /// Return the finish style vec and the common prefix chain.
- pub fn finish(mut self) -> (StyleVec<T>, StyleChain<'a>) {
- self.flush(false);
- self.builder.finish()
- }
-
- /// Push the staged items, filtering out weak items if `supportive` is
- /// false.
- fn flush(&mut self, supportive: bool) {
- for (item, styles, meta) in self.staged.drain(..) {
- if supportive || meta.is_none() {
- self.builder.push(item, styles);
- }
- }
- }
-}
-
-impl<'a, T> Default for CollapsingBuilder<'a, T> {
- fn default() -> Self {
- Self::new()
- }
-}