Re: Modification of read-only value error when using closure

The error is from attempting to modify $_[0] when the argument is a string literal, $rollup->(" ") rather than a variable $rollup->($dummy). The string literal is a constant, not an lvalue.

After Compline,
Zaxo

Comment on Re: Modification of read-only value error when using closure

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Re^2: Modification of read-only value error when using closure by sk (Curate) on Aug 24, 2005 at 05:12 UTC
Thanks Zaxo!!! I was under the impression that args are sent as values through @_ and thought that this problem was something to do with closures. I went back and tried a chomp on simple sub and the same happened. I checked `perldoc perlsub` and i got this info `Any arguments passed in show up in the array @_. Therefore, if you ca +lled a function with two arguments, those would be stored in $_[0] an +d $_[1]. The array @_ is a local array, but its elements are aliases + for the actual scalar parameters. In particular, if an element $_[0 +] is updated, the corresponding argument is updated (or an error occu +rs if it is not updatable).` [download] Now it is clear to me! thanks again! cheers SK	[reply] [d/l] [select]

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Re^2: Modification of read-only value error when using closure
by sk (Curate) on Aug 24, 2005 at 05:12 UTC

Zaxo

I was under the impression that args are sent as values through @_ and thought that this problem was something to do with closures. I went back and tried a chomp on simple sub and the same happened. I checked perldoc perlsub and i got this info

Any arguments passed in show up in the array @_.  Therefore, if you ca
+lled a function with two arguments, those would be stored in $_[0] an
+d $_[1].  The array @_ is a local array, but its elements are aliases
+ for the actual scalar parameters.  In particular, if an element $_[0
+] is updated, the corresponding argument is updated (or an error occu
+rs if it is not updatable).
[download]

Now it is clear to me!

thanks again!

cheers

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[select]