The conversion is required to properly support indexing for any index != 0. Optimizations are only possible if iterator-style APIs are used so the runtime can i

The conversion is required to properly support indexing for any index != 0. Optimizations are only possible if iterator-style APIs are used so the runtime can iterate as well. However, it might be still more efficient to convert the whole string and be done with it, depending on its length. Languages with a proper WASM backend could offer optimized runtime libraries and/or optimize such code. The issue is not new. JavaScript runtimes frequently use multiple optimized string types for various situations: https://github.com/danbev/learning-v8/blob/master/notes/string.md https://github.com/danbev/learning-v8/blob/master/notes/stri...