Context::Preserve Run code after a subroutine call, preserving the context the subroutine would have seen if it were the last statement in the caller
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Context::Preserve Ranking & Summary

Context::Preserve Tags

Perl module perl call subroutine subroutine call preserve context

Context::Preserve Description

Run code after a subroutine call, preserving the context the subroutine would have seen if it were the last statement in the caller Context::Preserve is a Perl module that helps you to run code after a subroutine call, preserving the context the subroutine would have seen if it were the last statement in the caller.SYNOPSISHave you ever written this? my ($result, @result); # run a sub in the correct context if(!defined wantarray){ some::code(); } elsif(wantarray){ @result = some::code(); } else { $result = some::code(); } # do something after some::code $_ += 42 for (@result, $result); # finally return the correct value if(!defined wantarray){ return; } elsif(wantarray){ return @result; } else { return $result; }Now you can just write this instead: use Context::Preserve; return preserve_context { some::code() } after => sub { $_ += 42 for @_ };Sometimes you need to call a function, get the results, act on the results, then return the result of the function. This is painful because of contexts; the original function can behave different if it's called in void, scalar, or list context. You can ignore the various cases and just pick one, but that's fragile. To do things right, you need to see which case you're being called in, and then call the function in that context. This results in 3 code paths, which is a pain to type in (and maintain).This module automates the process. You provide a coderef that is the "original function", and another coderef to run after the original runs. You can modify the return value (aliased to @_) here, and do whatever else you need to do. wantarray is correct inside both coderefs; in "after", though, the return value is ignored and the value wantarray returns is related to the context that the original function was called in. Requirements: · Perl

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