Exception Expressions

Currently, EYEDB OQL does not provide full support for exception management as there is no try/catch operator. Nevertheless, the throw operator allows us to raise an error message, for instance:

if (!check(p))
  throw "variable p is not correct".

The throw operator stops the current thread of statements and returns the error message at the uppest level. In the following code:

a := 1;
throw "this is an error";
b := 2;

the variable a will be assigned to 1, but the variable b will not be assigned to 2 as the throw expression deroutes the normal thread of statements. The throw operator is often used in the body of functions,

General Information
Operator	throw
Syntax	throw expr
Type	unary
Operand Type	string
Result Type	nil
Functions	raises an error message

Expression Examples
throw "error message"	nil
throw "error #1: " + msg	nil