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10.24.06
Perl Loop Causes Strange Read-only Error
 By
A.P. Lawrence
Ok, folks: I don't understand this. It must have something to do with anonymous arrays in Perl (no, it doesn't, I realize now), but I don't grok the connection.
I ran into this in attempting a seemingly simple change in some customer's code; it wasn't hard to fix, but I simply do not understand why this happened.
Well, that's not precisely true: it happened because I went ahead in a hurry and added something "quick". It was just a new loop around some existing code. Ordinarily I would have written it like this:
But for some reason I did this instead:
When run, that produces:
Caroomba called first
Caroomba called foo
Caroomba called ba
Caroomba called foo2
Caroomba called ba2
Caroomba called foo3 Modification of a read-only value attempted at ./t.pl line 23, <I> line 23.
Why? Dude, werent you listening? I do not comprehend why. Some person with more brains than I currently have will have to explain that one to both of us.
*Originally published at APLawrence.com
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