`throwAsCaller`

Raises an exception as if it came from the calling function.

Category: Programming > Programming Utilities

Syntax

throwAsCaller(ME)

Throws ME with the call stack trimmed so the error appears to originate in the caller.

Description

A function that validates its inputs usually wants the error attributed to the call that made the mistake, not to an internal helper. throwAsCaller removes the current function from the reported stack for that purpose. The identifier and message are unchanged.

Input arguments

ME: An MException object.

Example

Reporting a bad argument to the caller

function r = safeSqrt(x)
    if x < 0
        throwAsCaller(MException('safe:neg', 'x must be nonnegative'));
    end
    r = sqrt(x);
end
disp(safeSqrt(16))
try
    safeSqrt(-1)
catch err
    disp(err.message)
end

Output

     4
x must be nonnegative

Notes

MatLivre raises the error normally, so the reported location is not adjusted.

throwAsCaller