Comments on: Defensive programming is so groovy

By: The Disco Blog » Blog Archive » Concisely operating with ternaries

The Disco Blog » Blog Archive » Concisely operating with ternaries — Sat, 17 May 2008 16:24:20 +0000

[…] operating with ternaries One of my favorite features in Groovy is its hip ? operator, which facilitates Nullpointer navigation safety– while this feature isn’t available […]

By: it-bbr

it-bbr — Thu, 24 Apr 2008 09:26:01 +0000

It´s so easy to be save - but is utterly unused

By: The Disco Blog » Blog Archive » Unadulterated Java is so groovy

The Disco Blog » Blog Archive » Unadulterated Java is so groovy — Fri, 07 Mar 2008 20:08:34 +0000

[…] back to the getGenre method on the Song class, it turns out that Groovy also has a handy syntax for null pointer safety, consequently, I can simply that method even […]

By: Jason Rudolph

Jason Rudolph — Wed, 20 Feb 2008 04:19:07 +0000

Guillaume, Guillaume, Guillaume - *Please* don’t encourage people to write code like that. While this operator is indeed handy at times, I’d only trust about 2% of all programmers to use it appropriately. (To be clear, I’m not saying that Groovy shouldn’t offer this method. It absolutely should be there. I’m simply saying that 98% of the people that employ it will do so poorly and in a manner that compensates for generally shoddy code.)

Andy - You’re right on about the false confidence of 100% code coverage. (Jay Fields has a good post on this topic.) Bottom line: When it’s that easy to get 100% test coverage and still have buggy code, there’s simply no excuse for having anything less that 100% coverage. In fact, one could argue that 100% coverage is for underachievers.

By: Defensive Programming in Groovy | foojam.com

Defensive Programming in Groovy | foojam.com — Wed, 20 Feb 2008 01:28:44 +0000

[…] ? operator saves you from constantly having to check for null. Andrew Glover has a good example of Defensive Programming with Groovy over at The Disco Blog […]

By: Randy Hudson

Randy Hudson — Tue, 19 Feb 2008 16:29:35 +0000

Adam, one way of acccomplishing what you want is to use the ?: (’elvis’) operator:

genre?.toUpperCase() ?: ”

This operator (new to 1.5) returns the first expression unless it’s a false (null, 0, empty, false) value, else the second expression.

Also note that “${null}” evaluates to ‘null’, not ”.

By: Adam Kruszewski

Adam Kruszewski — Tue, 19 Feb 2008 13:32:49 +0000

What I have to write if I would like to return empty (ie. “”) gstring in place of null in your example?

Don’t you think it should make a difference to write:
“${genre?.toUpperCase()}”
and
${genre?.toUpperCase()}

The first case, in my opinion, should return empty GString.
The second should return null.
If both cases return null then the GString decalaration is a little bit misleading.

Cheers,
a.

By: Disco Articles » Blog Archive » Defensive programming is so groovy

Disco Articles » Blog Archive » Defensive programming is so groovy — Mon, 18 Feb 2008 22:46:05 +0000

[…] Original post by Andy […]

By: Andy

Andy — Mon, 18 Feb 2008 18:08:10 +0000

Good call, sir– I haven’t the slightest clue why I am working with a GString in that method. Thanks for pointing that out, man, and yeah– the deep object graph example is right on.

By: Guillaume Laforge

Guillaume Laforge — Mon, 18 Feb 2008 17:54:25 +0000

Why even putting everything inside a GString? You just need to return genre?.toUpperCase().

This trick is also more appealing when you have to go through some deep objectgraph. So instead of nested if / else, you can just return car?.make?.name?.toUpperCase() withouth having to check whether car is null, and make is null, and name is null, etc.