case    in el""Q
^~~~ expected a predicate for a case matching statement
             ^ expected a delimiter after the patterns of an `in` clause
               ^ unexpected constant, expecting end-of-input
 !"""#{in el"":Q
       ^~ unexpected 'in', assuming it is closing the parent 'in' clause
       ^ expected a `}` to close the embedded expression
       ^~ cannot parse the string part
          ^~ cannot parse the string part
            ^ cannot parse the string part
    ^~~~~~~~~~~ unexpected label
    ^~~~~~~~~~~ expected a string for concatenation
               ^ expected an `end` to close the `case` statement