Add support for self-modifying programs to core

ui/code-editor/monaco-utils.ts

@@ -1,5 +1,5 @@
 import monaco from "monaco-editor";
-import { DocumentRange } from "../../engines/types";
+import { DocumentEdit, DocumentRange } from "../../engines/types";
 import { WorkerParseError } from "../../engines/worker-errors";
 
 /** Type alias for an instance of Monaco editor */
@@ -60,6 +60,26 @@ export const createValidationMarker = (
   };
 };
 
+/**
+ * Convert a DocumentEdit instance to Monaco edit object format.
+ * @param edit DocumentEdit to convert to Monaco format
+ * @returns Instance of Monaco's edit object
+ */
+export const createMonacoDocEdit = (
+  edit: DocumentEdit
+): monaco.editor.IIdentifiedSingleEditOperation => {
+  const location = get1IndexedLocation(edit.range);
+  return {
+    text: edit.text,
+    range: {
+      startLineNumber: location.line,
+      endLineNumber: location.line,
+      startColumn: location.charRange?.start || 0,
+      endColumn: location.charRange?.end || 1000,
+    },
+  };
+};
+
 /**
  * Convert a DocumentRange to use 1-indexed values. Used since language engines
  * use 0-indexed ranges but Monaco requires 1-indexed ranges.