I'm seeing this error when I try to use the new TYPEOF operator in the query editor.. 

Warning 1 Message: extraneous input 'TYPEOF' expecting {AVG, CONVERT_CURRENCY, COUNT, 
COUNT_DISTINCT, FORMAT, MAX, MIN, SUM, TO_LABEL, CALENDAR_MONTH, CALENDAR_QUARTER, 
CALENDAR_YEAR, DAY_IN_MONTH, DAY_IN_WEEK, DAY_IN_YEAR, DAY_ONLY, FISCAL_MONTH, 
FISCAL_QUARTER, FISCAL_YEAR, HOUR_IN_DAY, WEEK_IN_MONTH, WEEK_IN_YEAR, CONVERT_TIMEZONE,
 DISTANCE, '(', Identifier}

It says warning but I don't get any records back, so I think this is an error & a bug. The same query does work in the developer console. 

It looks like a nice feature: https://developer.salesforce.com/docs/atlas.en-us.soql_sosl.meta/soql_sosl/sforce_api_calls_soql_select_typeof.htm

edit: I now see that when I change the api version on the project properties, it does not stick. It was 45.0 and I changed it to 46.0. If I go into the properties again, it's back to 45.0. If I restart TWS or even edit the sfproj manually, it goes back to 45.0. I don't know if this is causing the problem above or not..