catch - catch errors
Evaluate 'expr'. If there is no error, 0 is returned. If there
is a standard error, a string (with a leading '*') will be returned.
The function throw(value) can also be used to immediately return
any value, except 0.
- NOTA BENE
The catch() is somewhat costly, and should not be used anywhere.
Rather, use it at places where an error would destroy consistency.
- SEE ALSO