+fbstring stripComments(StringPiece jsonC) {
+ fbstring result;
+ enum class State {
+ None,
+ InString,
+ InlineComment,
+ LineComment
+ } state = State::None;
+
+ for (size_t i = 0; i < jsonC.size(); ++i) {
+ auto s = jsonC.subpiece(i);
+ switch (state) {
+ case State::None:
+ if (s.startsWith("/*")) {
+ state = State::InlineComment;
+ ++i;
+ continue;
+ } else if (s.startsWith("//")) {
+ state = State::LineComment;
+ ++i;
+ continue;
+ } else if (s[0] == '\"') {
+ state = State::InString;
+ }
+ result.push_back(s[0]);
+ break;
+ case State::InString:
+ if (s[0] == '\\') {
+ if (UNLIKELY(s.size() == 1)) {
+ throw std::logic_error("Invalid JSONC: string is not terminated");
+ }
+ result.push_back(s[0]);
+ result.push_back(s[1]);
+ ++i;
+ continue;
+ } else if (s[0] == '\"') {
+ state = State::None;
+ }
+ result.push_back(s[0]);
+ break;
+ case State::InlineComment:
+ if (s.startsWith("*/")) {
+ state = State::None;
+ ++i;
+ }
+ break;
+ case State::LineComment:
+ if (s[0] == '\n') {
+ // skip the line break. It doesn't matter.
+ state = State::None;
+ }
+ break;
+ default:
+ throw std::logic_error("Unknown comment state");
+ }
+ }
+ return result;
+}
+