goto function
Create spaghetti code
goto LABEL
goto EXPR
goto &NAME
The goto-LABEL form finds the statement labeled with LABEL and resumes execution
there. It may not be used to go into any construct that requires initialization, such as a subroutine or a foreach
loop. It also can't be used to go into a construct that is optimized away, or to get out of a block or subroutine
given to sort(). It can be used to go almost anywhere else within the dynamic scope, including
out of subroutines, but it's usually better to use some other construct such as last or
die(). The author of Perl has never felt the need to use this form of goto
(in Perl, that is--C is another matter).
The goto-EXPR form expects a label name, whose scope will be resolved dynamically. This allows
for computed gotos per FORTRAN, but isn't necessarily recommended
if you're optimizing for maintainability:
goto ("FOO", "BAR", "GLARCH")[$i];
The goto-&NAME form is highly magical, and substitutes a call to the named subroutine for the
currently running subroutine. This is used by AUTOLOAD subroutines that wish to load another subroutine
and then pretend that the other subroutine had been called in the first place (except that any modifications to
@_ in the current subroutine are propagated to the other subroutine.) After the goto,
not even caller() will be able to tell that this routine was called first.
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