Java is Death By A Thousand Paper Cuts

At least it is for me. This past week at work I've been furiously rushing work on a project written in Java. It's completely my fault that I'm using Java since I'm the one who picked the language. I wanted to use Java the platform, but I don't know any other JVM languages well enough to use them in place of Java the language for a project at work.

It's all sorts of little things that make writing Java so exhausting for me. At the end of the day it I just feel irritated. I hate the absolute lack of functional programming and that I have to specify everything at such a low level. The whole reason we program in high-level languages is so we can express algorithms more concisely, but Java fails at this.

Here's an example of what I'm talking about, something I basically did a few times today. Let's say you have an array of floats, nums and you want to sum them and return the result (or maybe use it in another expression). In Lisp it's very straightforward.

(reduce '+ nums)

"Reduce the sequence nums by addition." Notice that it's more about saying what I want to do rather than how to do it. I don't have to introduce any temporary storage or iterators. To do the same thing in Java it will look something like this.

int sum = 0;
for (double num : nums) {
    sum += num;
return sum;

If you're using an older Java without the enhanced looping construct it gets even uglier. I had to introduce a variable for accumulation and a second variable for iteration. This sort of thing has to be done all over the place in Java, and it greatly increases the cognitive overload when reading Java code.

This instruction is more about telling the computer the how rather than my overall intention. One problem with telling it the how is that I've unnecessarily locked in a specific algorithm and ordering. The literal instruction says that the numbers must be added in order, sequentially. My Lisp instruction doesn't do that.

It gets even worse when you complicate it slightly by adding a second array and, say, multiplying it pairwise with the first.

for (int i = 0; i < nums1.length; i++) {
    sum += nums1[i] * nums2[i];
return sum;

Now the loop gets more complex. I have to tell it how to increment the iterator. I have to tell it to check the bounds of the array. The iterator is a misdirection because the actual number stored in it isn't what's important. Again, the Lisp method is much more concise.

(reduce '+ (map 'list '* nums1 nums2))

"Map the two sequences by multiplication into a list, then reduce it by addition." Unfortunately we start to leak a little bit into the how here. I am telling it that the intermediate structure should be a list, because map forces me to pick a representation. Besides that, I am only describing my overall intention and not the obvious details.

So with Java my days become filled with the tedious low-level algorithm descriptions that I have to hammer out over and over and over. Death by a thousand paper cuts.

Lisp isn't the only language that has a (generally) much better approach; it's just my favorite. :-) Most languages with at least some decent functional facilities will also do the above concisely.

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Chris Wellons (PGP)
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