All errors can end with the form:  "line L, column C", giving the coordinates
of one of the first tokens in the offending construct.

incompatible types: R required, but F found
duplicate class: C
cannot resolve parent class: C
cyclic inheritance involving C
incompatible method override: M
F is already defined in M
TypeChecker::visit(AbstractList) unexpected item O
operator B cannot be applied to L,R
operator U cannot be applied to E
incompatible types: array required, but T found
target not object type O
cannot resolve method: M
cannot resolve field: F
implicit self parameter not compatible T, S
mismatch in number of arguments
cannot resolve symbol: S
cannot resolve this pointer
cannot resolve name: C