[lobster_johnson]

We used to use viewport biasing, but I forget why it's no longer enabled; it's been a long time since I worked on this. I know we do use component filtering, and I can tell you that with "components=administrative_area:MT|country:US", typing "M" will yield "Montana, MT" and that will be the only result. You have to type as far as "Missou" to get Missoula as a result.

Generally, the geocoder's substring matching has limited range, which is why it is fairly useless for autocompletion. Its partial matching seems limited to misspellings or nearly-complete terms. For example, I just tried typing "mead", and asked the API for 10 results. I got 5 results, all things like "Mead Lane" or "Meade Ave", but no "Meadowood". So it stopped at 5 even though there are more sharing that prefix. If I type "mea", I get just _one_ match, about some random place with "Mea" in the name. In other words, it's doing something else (something more sophisticated, but less appropriate for this use case) than mere prefix/substring matching.

Again, it's been a while, but from the last time I looked, I recall the Places API being better for this type of incremental autocompletion, but it had some issues related to geofencing that made it almost as bad.