Trapping an Exception with catch
The other way to trap an exception is to use the primitive
catch. The catch primitive is not
the same as the catch block in the try...catch
statement (this is because the catch statement was part
of the language long before try...catch was
introduced).
When an exception occurs within a catch statement, it is
converted into an {’EXIT’, ...} tuple that describes
the error. To demonstrate this, we can call
generate_exception within a catch
expression.
| try_test.erl | |
| | demo2() -> |
| | [{I, (catch generate_exception(I))} || I <- [1,2,3,4,5]]. |
Running this we obtain the following:
| | 2> try_test:demo2(). |
| | [{1,a}, |
| | {2,a}, |
| | {3,{'EXIT',a}}, |
| | {4,{'EXIT',a}}, |
| | {5,{'EXIT', |
| | {a,[{try_test,generate_exception,1, |
| | [{file,"try_test.erl"},{line,9}]}, ... |
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