Error Handling

There are three facilities for error handling in Maple: ERROR,
lasterror, and traperror.

ERROR

The syntax of the ERROR statement is simply:

ERROR(error-message-string);

The "ERROR" must be in capital letters.  When you use ERROR in
procedures to indicate that something has gone wrong, you will see a
message printed of the form:

Error, (in functname) error-message-string

As is the case with Maple-detected errors, the computation is then
interrupted and aborted.

lasterror and traperror

The variable lasterror records the most recent kind of ERROR.  The
function traperror evaluates an expression sequence and returns the
value if there were no errors, or lasterror if there was an error.  You
can use these two features in combination to control error handling
yourself instead of just having Maple interrupt and abort processing.