add hw2

node_modules/sucrase/dist/esm/util/isExportFrom.js

@@ -0,0 +1,18 @@
+import {ContextualKeyword} from "../parser/tokenizer/keywords";
+import {TokenType as tt} from "../parser/tokenizer/types";
+
+
+/**
+ * Starting at `export {`, look ahead and return `true` if this is an
+ * `export {...} from` statement and `false` if this is a plain multi-export.
+ */
+export default function isExportFrom(tokens) {
+  let closeBraceIndex = tokens.currentIndex();
+  while (!tokens.matches1AtIndex(closeBraceIndex, tt.braceR)) {
+    closeBraceIndex++;
+  }
+  return (
+    tokens.matchesContextualAtIndex(closeBraceIndex + 1, ContextualKeyword._from) &&
+    tokens.matches1AtIndex(closeBraceIndex + 2, tt.string)
+  );
+}