refactor:

- dedupe flash / highlighting logic
- codemirror logic now lives only in codemirror package
- remove old highlighting logic
- use codemirror package in react package
- cleanup CodeMirror6.jsx
- pull setMiniLocations into useHighlighting
- migrate MiniRepl, nano-repl + Repl to new highlighting

packages/codemirror/highlight.mjs

@@ -0,0 +1,126 @@
+import { RangeSetBuilder, StateEffect, StateField } from '@codemirror/state';
+import { Decoration, EditorView } from '@codemirror/view';
+
+export const setMiniLocations = StateEffect.define();
+export const showMiniLocations = StateEffect.define();
+export const updateMiniLocations = (view, locations) => {
+  view.dispatch({ effects: setMiniLocations.of(locations) });
+};
+export const highlightMiniLocations = (view, atTime, haps) => {
+  view.dispatch({ effects: showMiniLocations.of({ atTime, haps }) });
+};
+
+const miniLocations = StateField.define({
+  create() {
+    return Decoration.none;
+  },
+  update(locations, tr) {
+    if (tr.docChanged) {
+      locations = locations.map(tr.changes);
+    }
+
+    for (let e of tr.effects) {
+      if (e.is(setMiniLocations)) {
+        // this is called on eval, with the mini locations obtained from the transpiler
+        // codemirror will automatically remap the marks when the document is edited
+        // create a mark for each mini location, adding the range to the spec to find it later
+        const marks = e.value
+          .filter(([from]) => from < tr.newDoc.length)
+          .map(([from, to]) => [from, Math.min(to, tr.newDoc.length)])
+          .map(
+            (range) =>
+              Decoration.mark({
+                id: range.join(':'),
+                // this green is only to verify that the decoration moves when the document is edited
+                // it will be removed later, so the mark is not visible by default
+                attributes: { style: `background-color: #00CA2880` },
+              }).range(...range), // -> Decoration
+          );
+
+        locations = Decoration.set(marks, true); // -> DecorationSet === RangeSet<Decoration>
+      }
+    }
+
+    return locations;
+  },
+});
+
+const visibleMiniLocations = StateField.define({
+  create() {
+    return { atTime: 0, haps: new Map() };
+  },
+  update(visible, tr) {
+    for (let e of tr.effects) {
+      if (e.is(showMiniLocations)) {
+        // this is called every frame to show the locations that are currently active
+        // we can NOT create new marks because the context.locations haven't changed since eval time
+        // this is why we need to find a way to update the existing decorations, showing the ones that have an active range
+        const haps = new Map();
+        for (let hap of e.value.haps) {
+          for (let { start, end } of hap.context.locations) {
+            let id = `${start}:${end}`;
+            if (!haps.has(id) || haps.get(id).whole.begin.lt(hap.whole.begin)) {
+              haps.set(id, hap);
+            }
+          }
+        }
+
+        visible = { atTime: e.value.atTime, haps };
+      }
+    }
+
+    return visible;
+  },
+});
+
+// // Derive the set of decorations from the miniLocations and visibleLocations
+const miniLocationHighlights = EditorView.decorations.compute([miniLocations, visibleMiniLocations], (state) => {
+  const iterator = state.field(miniLocations).iter();
+  const { haps } = state.field(visibleMiniLocations);
+  const builder = new RangeSetBuilder();
+
+  while (iterator.value) {
+    const {
+      from,
+      to,
+      value: {
+        spec: { id },
+      },
+    } = iterator;
+
+    if (haps.has(id)) {
+      const hap = haps.get(id);
+      const color = hap.context.color ?? 'var(--foreground)';
+      // Get explicit channels for color values
+      /* 
+      const swatch = document.createElement('div');
+      swatch.style.color = color;
+      document.body.appendChild(swatch);
+      let channels = getComputedStyle(swatch)
+        .color.match(/^rgba?\((\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3})(?:,\s*(\d*(?:\.\d+)?))?\)$/)
+        .slice(1)
+        .map((c) => parseFloat(c || 1));
+      document.body.removeChild(swatch);
+
+      // Get percentage of event
+      const percent = 1 - (atTime - hap.whole.begin) / hap.whole.duration;
+      channels[3] *= percent;
+      */
+
+      builder.add(
+        from,
+        to,
+        Decoration.mark({
+          // attributes: { style: `outline: solid 2px rgba(${channels.join(', ')})` },
+          attributes: { style: `outline: solid 2px ${color}` },
+        }),
+      );
+    }
+
+    iterator.next();
+  }
+
+  return builder.finish();
+});
+
+export const highlightExtension = [miniLocations, visibleMiniLocations, miniLocationHighlights];