1 files changed, 10 insertions, 0 deletions
diff --git a/src/parser/utils/full_char_code_at.ts b/src/parser/utils/full_char_code_at.ts
new file mode 100644
index 000000000..fea5151b6
--- /dev/null
+++ b/src/parser/utils/full_char_code_at.ts
@@ -0,0 +1,10 @@
+// Adapted from https://github.com/acornjs/acorn/blob/6584815dca7440e00de841d1dad152302fdd7ca5/src/tokenize.js
+// Reproduced under MIT License https://github.com/acornjs/acorn/blob/master/LICENSE
+
+export default function full_char_code_at(str: string, i: number): number {
+  const code = str.charCodeAt(i);
+  if (code <= 0xd7ff || code >= 0xe000) return code;
+
+  const next = str.charCodeAt(i + 1);
+  return (code << 10) + next - 0x35fdc00;
+}