Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?

Re^5: No garbage collection for my-variables

by vrk (Chaplain)
on Sep 17, 2008 at 08:20 UTC ( #711921=note: print w/replies, xml ) Need Help??

in reply to Re^4: No garbage collection for my-variables
in thread No garbage collection for my-variables

They are. funcall(<variable assignment>) is a useful idiom in programming languages where assigment returns (an alias to) the value of the variable, but it is counter-intuitive at first. Even though I have been programming in Perl and curly brace block syntax languages for years, I still find it hard to read -- mostly because when you normally delimit my with braces, you create a new lexical scope. That's what chomp(my $foo = bar) still seems to be, even if I know better and use the idiom frequently.

Not only that, but it is not obvious that the value of $var in chomp(my $var = <$fh>) is being modified at all! After all, assignment, if used in other contexts, returns the value, not a reference to it. my $foo = $bar = 1 doesn't create a reference in $foo, but sets the value of both variables to 1. In fact, I am not sure what the underlying mechanism is. Does it work because assignment returns an alias similar to aliased values in @_ in function calls?

Side-effect free chomp has no similar conceptual problems.

say "Just Another Perl Hacker";

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://711921]
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others wandering the Monastery: (8)
As of 2018-06-19 15:07 GMT
Find Nodes?
    Voting Booth?
    Should cpanminus be part of the standard Perl release?

    Results (114 votes). Check out past polls.