Re: What operator prepends?

Usually, when I want to prepend, I just change the order of operations into an append. Instead of:

  $script = 'foo.pl';
  # or $script = <STDIN>; chomp $script;
  $path = '/some/path/';
  $script = $path . $script;
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I'll do:

  $script = '/some/path';
  $script .= 'foo.pl';
  # or $script .= <STDIN>; chomp $script;
[download]

Often, I find that this actually makes more sense in my head because I'm building my string from left to right, which is how I think of the string.

Alternatives is to build the string from pieces using sprintf or join. And, in my particular example, an option would be to use the join-like File::Spec.

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Re^2: What operator prepends? by swampyankee (Parson) on Jan 25, 2006 at 21:56 UTC
Why not just something like `$string = $prefix . $string;` [download] emc " When in doubt, use brute force." — Ken Thompson	[reply] [d/l]
Re^3: What operator prepends? by Tanktalus (Canon) on Jan 25, 2006 at 22:21 UTC
First off, "= [...] ." isn't an operator as per the original topic. That's two operators. ;-) However, more importantly, this is just not how I mentally think of creating a string. If I want to generate a string such as "this is the output", I don't think about starting with the string "output" and prepending a bunch of stuff. I think about how to create "this", then I think of how to create "is", etc. It's actually quite rare that I'll want to generate "the" before I generate "is". In fact, I often end up with code like this: `my @text; push @text, generate_this(); push @text, generate_is(); push @text, generate_the_output(); return join ' ', @text;` [download] That's just how I think of the string, and I find that when my code matches the problem in my head, it's far less likely to have bugs in it. Especially expensive design bugs.	[reply] [d/l]
Re^4: What operator prepends? by swampyankee (Parson) on Jan 26, 2006 at 03:46 UTC
I also tend to create my strings from left to right, probably because that's how I tend to write. I add stuff to the end -- `push` vs `unshift` -- so a "prepend" operator is not something I would think to include in a language design. Perhaps inaccurately, I don't think of `.=` the "append" operator; I think of it as an abbreviation for `$string = $string . $more`. emc " When in doubt, use brute force." — Ken Thompson	[reply]