Re: split slice?

If readability and/or maintanability is of concern, it might be of help to rephrase the code somewhat like this:

 
sub extract_and_add {
    my ($colon_sep_string, $extra_elem) = @_;

    my ($first, $second, $third, $ignore) = split( /:/, $colon_sep_str
+ing );

    return join('-', $second, $third, $extra_elem);

}
[download]

Meaningful sub and variable names are really easy to set once you get into the habit - and the extra time you'll take for that will return tenfold to you in the nearest future.

Not to mention the gratitude of the first person after you that will have to look on the code without being forced to hold on breathing for a second to concentrate on "what exactly is meant here...?!"

Hth.

Comment on Re: split slice? Download Code

Replies are listed 'Best First'.
Re^2: split slice? by CountZero (Bishop) on Oct 14, 2007 at 12:00 UTC
Another idiom I find useful and easy to understand is to simply assign the parts of the `split` you don't need to `undef`. The `split` would then become: `my (undef, $second, $third, undef) = split( /:/, $colon_sep_string );` which makes it obvious that you are not going to use the first and fourth field. CountZero A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James	[reply] [d/l] [select]
Re^2: split slice? by grinder (Bishop) on Oct 14, 2007 at 10:15 UTC
This is true in the general case, but I think it's completely the wrong advice in the present case. Why name something you don't care about? Specifically, `$first` and `$ignore`? Notwithstanding the fact that ignore is a really bad name. So is first, second and third but I assume you just named them that way for this example. The slice syntax is much clearer: it indicates that whatever is in offsets 0 and beyond 2 are of no importance. And if the elements are not heterogeneous, there's no point in naming them separately as they are members of a group rather than individual elements in their own right. Thus, they have no need for names. I find the code you posted less readable, as I have to spend time wondering what `$first` and `$ignore` are doing, and whether some code has been left off or accidentally removed that might have done something with them. And so I have to concentrate for a second and ask myself "what exactly is meant here...?!" • another intruder with the mooring in the heart of the Perl	[reply]