| Calling Sequence
| error(msg,...)
|
| Parameters
| | Name | Type | Description |
|
| msg
| anything | usually an error message |
| ...
| anything | additional arguments to clarify the error |
|
| Return Type
| NULL |
| Synopsis
| This function returns to the top level of execution
and issues the error message msg.
If an error happens while executing a traperror() function, then
the flow will not return to the top level, instead the
traperror function will return with the value of the argument(s) of
error().
When this happens, the global
variable "lasterror" is set to the value of the error, else it is
unassigned.
Using error/traperror allows for a simple throw-catch mechanism. |
| Examples
| > f := proc(x) if x=0 then error('oops, div by 0') fi; 5/x end;
f := proc (x) if x = 0 then error(oops, div by 0) fi; 5/x end
> f(0);
Error, (in f) oops, div by 0
> traperror(f(0));
oops, div by 0
> lasterror;
oops, div by 0
|
| See also
| lasterror, traperror |