Pinderkent

Yesterday a colleague forwarded me the link to Underscore.js. It's a JavaScript library that provides some functions commonly offered by functional programming language implementations.

Now, I can understand completely why JavaScript programmers would desire to use such techniques. They bring some very clear and powerful benefits, including shortened development time, fewer lines of code, greater flexibility, and improved readability. However, I do hope that JavaScript programmers using such a library don't come to think that they're actually doing functional programming.

One of the most significant areas where JavaScript fails with respect to functional programming is immutability. Current implementations have spotty support for constants, leading to various workarounds. So while it's possible to manually avoid state changes as much as is possible, it becomes difficult to do when performing browser-based JavaScript development. And it's almost always better to have the language implementation strictly enforce const-ness, rather than trying to have developers communicate this intent through all-caps variable names, for instance.

Many functional languages also offer very rich pattern matching functionality, which we just don't get with JavaScript. While some people have tried to implement pattern matching in JavaScript, it is nowhere near as clean or natural as pattern matching in Haskell or pattern matching in Erlang.

Many, but not all, functional programming languages also offer strict, static typing. There has been much debate about the pros and cons of the various typing techniques employed by various languages. In the end, however, experience shows that static typing results in higher-quality software, and static typing saves developer time. Unfortunately, JavaScript as a language, as well as its current widely-used implementations, don't lend themselves to strong, static typing.

It also doesn't help that JavaScript came mainly from the imperative and prototype-based OO world, and is only now trying to adopt features and techniques from the functional paradigm. It's often much cleaner to start with a purely functional language, and then add useful imperative features like for loops and references, as was done with Objective Caml. So the language and standard libraries have a functional feel to them, and naturally encourage the use of functional techniques, yet still allow the use of imperative features where they may prove to be the best option.

In many respects, I see trying to do functional programming in JavaScript much like doing object-oriented programming in C. While it can be done, to some extent, it never feels very natural because it lacks support that should be provided at the language level and by the implementations of said language. GObject is one of the most widely used C object systems, and as anyone who has written even a moderately sized GTK+-based system in C knows, it's not a very pleasant ordeal. Languages like Objective-C and C++ offer a much more developer-friendly experience.

So I see trying to add features and techniques from functional programming to JavaScript as generally being a pointless exercise. It may help in some cases, but ends up just masking the symptoms of a greater problem, namely that we want (and maybe even need) a true functional programming language available in all of the popular Web browsers. I've suggested Haskell in the past, but just about any functional language would be better than JavaScript.

Anybody working on business applications these days will undoubtedly have to familiarize himself or herself with one or more existing databases. These databases have often been "grown" rather than designed in any meaningful way, and thus will be littered with unused tables, unused functions or stored procedures, missing constraints, poor normalization, and a host of other problems.

Developers in such a situation will often look for an easy way out, such as the use of tools to automatically reverse-engineer various parts of the existing database or databases. While these tools can be useful, I don't think they are ever a replacement for just stepping through the code, line-by-line, and observing exactly what queries are executed.

Depending on the application, it may even be a bad idea to try and think of the application and database as separate. Many times we find that one can't exist without the other, and vice versa. For instance, we find hard-coded SQL queries within the application code written in languages like Java, PHP or C#. In such situations, one literally has to take a debugger and step through the application code in order to get even a basic understanding of how the system works.

Another thing that may be worth avoiding is trying to understand the system all at once. Often, it will take many months to truly grasp even a moderately sized application and the database behind it. As changes are made or bugs are fixed, take a moment or two to study and document the code paths that are involved. Doing this on a daily basis will eventually expose a developer to large portions of the software system they're working with.

Regardless of the approach, one thing to keep in mind that it's not an easy task becoming familiar with existing codebases and databases, especially when they're as ugly as so many real-world systems are. Give it time, remain patient, and eventually the system will start to feel much smaller and manageable.

Chris Eargle recently wrote about so-called "utility" or "helper" classes. Within his article, he states that "There should never be a Utility class which is used as a general bucket. Every method in your system means something, it belongs somewhere." I can agree with this sentiment, nor can I necessarily argue in favor of using such classes. However, I do think that a tendency for developers to create such classes indicates that there is likely an inherent flaw with the programming language that they're using.

We most often see "utility" or "helper" classes arise when using languages like Java and C#. When first developed, these languages took an OO-or-nothing approach. This isn't surprising, especially in the case of Java. When it arose during the 1990s, the software development community as a whole was generally quite enthusiastic about object-oriented programming. So one notable feature it is missing is the traditional function.

Many OO purists will decry the functions and procedures that are native to many imperative languages. They claim there is no place for standalone functions within object-oriented languages and well-designed software. But it really just comes down to a typical clash of theory versus pragmatism. When developing real-world software, sometimes a plain old function is exactly the tool that we need.

So while languages like C++, Python and even OCaml allow for both functions and objects to be used, Java and C# unfortunately do not. Developers using languages like Java and C# have to resort to abstract classes with static methods, or similar workarounds. As Chris notes in his article, this isn't an ideal situation by any means.

Given that we, as a community, now have many more years of developing software using object-oriented languages and techniques, I think it's safe to say that our tools may need some minor modifications. Languages like Java and C# are missing an essential construct, and that construct is the function. Like any tool, functions can be misused. But as we've seen, their absence can result in other hackish designs that pose several problems of their own. So perhaps we will eventually see this deficiency addressed by adding functions to such languages, so we can use them when they do prove to be the best tool for getting the job done.