Re^2: Optimal way to read in pipe delimited files

you can take this two steps further by getting rid of $key and using a map:

%prod=map{chomp;@a=split/\|/;shift@a,[@a]}<SRC>;
[download]

or, expanded,

%prod = map {
  chomp;
  @a = split /\|/;
  shift(@a) => [@a]
} <SRC>
[download]

You have to do [@a] instead of \@a if you do not localize the array with "my".

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Re^3: Optimal way to read in pipe delimited files by Roy Johnson (Monsignor) on Nov 09, 2005 at 22:29 UTC
I think that's one step too far. Specifically, getting rid of a descriptive scalar in favor of lumping all the values together and using `shift`. I don't see any advantage in performance or clarity. Caution: Contents may have been coded under pressure.	[reply] [d/l]
Re^3: Optimal way to read in pipe delimited files by narashima (Beadle) on Nov 09, 2005 at 22:34 UTC
Could someone please explain the significance of `shift@a,[@a]` in the above map? I tried removing this statement and it did not work. I really dont know what that statement is doing. Also I did not understand why `[@a]` is to be used if my is not used. thanks narashima	[reply] [d/l] [select]
Re^4: Optimal way to read in pipe delimited files by duff (Parson) on Nov 09, 2005 at 22:51 UTC
Because `my` gives you a new variable each time through the loop, you can use `\@a` and all it well because it's a different `@a` each time. When you don't use `my` within the loop, it's always the same variable. Thus `@a = (1,2,3); $a = \@a; @a =(4,3,9); $b = \@a;` will cause `$a` and `$b` to both reference the same memory location which will contain the values `(4,3,9)`. `[@a]` makes a copy of `@a` and returns a reference to it, so you get a new chunk of memory each time. duff	[reply] [d/l] [select]