1 files changed, 35 insertions, 0 deletions

diff --git a/subprojects/frontend/src/editor/findOccurrences.ts b/subprojects/frontend/src/editor/findOccurrences.ts
new file mode 100644
index 00000000..92102746
--- /dev/null
+++ b/subprojects/frontend/src/editor/findOccurrences.ts
@@ -0,0 +1,35 @@
+import { Range, RangeSet } from '@codemirror/rangeset';
+import type { TransactionSpec } from '@codemirror/state';
+import { Decoration } from '@codemirror/view';
+
+import { decorationSetExtension } from './decorationSetExtension';
+
+export interface IOccurrence {
+  from: number;
+
+  to: number;
+}
+
+const [setOccurrencesInteral, findOccurrences] = decorationSetExtension();
+
+const writeDecoration = Decoration.mark({
+  class: 'cm-problem-write',
+});
+
+const readDecoration = Decoration.mark({
+  class: 'cm-problem-read',
+});
+
+export function setOccurrences(write: IOccurrence[], read: IOccurrence[]): TransactionSpec {
+  const decorations: Range<Decoration>[] = [];
+  write.forEach(({ from, to }) => {
+    decorations.push(writeDecoration.range(from, to));
+  });
+  read.forEach(({ from, to }) => {
+    decorations.push(readDecoration.range(from, to));
+  });
+  const rangeSet = RangeSet.of(decorations, true);
+  return setOccurrencesInteral(rangeSet);
+}
+
+export { findOccurrences };