YieldExpression2_es6.ts(1,1): error TS1163: A 'yield' expression is only allowed in a generator body.
YieldExpression2_es6.ts(1,7): error TS2304: Cannot find name 'foo'.


==== YieldExpression2_es6.ts (2 errors) ====
    yield foo;
    ~~~~~
!!! error TS1163: A 'yield' expression is only allowed in a generator body.
          ~~~
!!! error TS2304: Cannot find name 'foo'.