All programmers have heard of GOTO, but far fewer have heard of COMEFROM:
In case you were tired of your control flow working in a comprehensible manner, you can now write programs that scan every time they move ahead a line, and leap to (at least) one COMEFROM whose conditions are satisfied.
Available in Intercal. Proposed at one point in Fortran (along with a DON'T loop to contrast the usual DO), but not implemented.

















