Saturday, February 21, 2015

How do you join the conversation? is great in that it's a stream of blog posts around a specific technology. Since I, like many of you, blog about other technologies too, I'd like to learn from you about other conversation streams. For me personally, the list of topics include:

  • Web development (JavaScript, CSS, etc)
  • Lifehacks
  • Unix, Linux, shell scripting
  • General tech / tech business
  • Database

I'll add what little knowledge I have on the topic:

There's reddit with corresponding subreddits on Unix and Perl. It looks like it's pretty routine to post blog entries on the Perl one at least, I'm not sure about the climate of other tech subreddits.

There are also subreddits for LifeProTips and Life Hacks. I've not yet participated in either, so again I'm not sure what the expectations are.

The Unix and Linux Forums, while not a "stream" of conversation, seems to be receptive to sharing ideas, and the people there are friendly and helpful.

And of course, Twitter with and without #perl and #unix hashtags. I say with or without as it seems like more popular bloggers, at least, don't bother with the hashtags. I'll also say that with or without the hashtags I haven't seen a lot of traffic coming from Twitter.

I'd appreciate anyone's advice, experience, or knowledge on this topic.


Tuesday, February 10, 2015

Fix Those Legacy Subroutines or Methods

Maybe you know the feeling… you go to add an option to that method or subroutine and… cue Jaws theme

sub update_shopping_cart {
    my $cart_id        = shift;
    my $item           = shift;
    my $quantity       = shift;

Argh. You don’t want your legacy code to break but you also don’t want to add a fourth unnamed parameter to the existing problem. And the solution is simple:

sub update_shopping_cart {
    my $cart_id        = shift;
    my $item           = shift;
    my $quantity       = shift;
    my $apply_discount = 0;        # Initialize the fourth parameter

    my $param1 = $cart_id;
    if ( ref $param1 eq 'HASH' ) {
        $cart_id        = $param1->{cart_id};
        $item           = $param1->{item};
        $quantity       = $param1->{quantity};
        $apply_discount = $param1->{apply_discount};

Now either of these work. The legacy call:

update_shopping_cart( 314, 'apples', 3 );

…or the new style:

    cart_id        => 314,
    item           => 'apples',
    quantity       => 3,
    apply_discount => 1,

Bonus: there is no way to use the new option with the old-style call. If someone wants to use it, they’ll need to switch to the new style.

  • The new call is self-documenting. In the original form of the call, you see “314” in the code by itself, and it’s not immediately obvious what it is. Now it’s nicely labeled.
  • Now that you have added the new format, you can painlessly add additional named parameters as needed.

  • It may be confusing to see two different styles of calls in your codebase. But, now you can transition the old code piecemeal.