Daniel's Blog

Knowing a Language

Posted by Daniel Lyons Fri, 07 Sep 2007 08:46:00 GMT

Apparently people are talking about what it means to know a language. The debate seems to be centered around whether or not knowing the language syntactically or in terms of the library is what really constitutes “knowing” it.

Even in natural language there is disagreement around this kind of thing. Some teachers prefer to focus on vocabulary, others on grammar. Many others prefer immersion to formal methods. I think this translates roughly to teaching programming in terms of idiomatic forms.

I’ve been exposed to all of those methods of learning a language in computer science. Lots of people buy, read and are devoted to “cookbooks.” I have found that, although they are often good, some are overly simplistic (O’reilly’s PHP Cookbook comes to mind), but neither is really a good substitute for reading actual code in the language. Immersion, if you will.

In Compiler Writing in college, we were required to implement a compiler for a language nobody knew which bore very little resemblance to other languages we knew (Tiger). In that class I got to exercise my skills at reading a BNF specification of a grammar, and I was able to write code that should have compiled pretty easily with just a little bit of studying. This doesn’t come up very often, because usually there is a body of code to learn from idiomatically. There are no idioms for Tiger, because nobody uses it enough to establish them and it’s designed to by syntactically troublesome without being particularly expressive in the first place. (I did once email the REALbasic developers to see if they would supply me with a BNF for the language, and I was told it didn’t exist). So the skill is nice to have but comes up very rarely.

The author above is, I believe, reaching for the same idea of idiomatic use in talking about max() in Python, because anyone who really understood Python would use it. At the same time, I have to say there’s more to it than that, because someone who really knew Python would know not only the idioms but also when not to use them. Lots of English speakers do not use “me” and “whom” correctly (including me, sometimes). True mastery includes that level of knowledge. For many languages, it probably includes a certain amount of knowledge about the implementation, or at least an intuition as to what equivalent constructs are going to perform faster, for example.

But taking this concept even further, I would say nobody is master of any programming language without knowing at least one other programming language. Linguistic myopia is a huge problem. Languages are primarily tools. If you think there are no better tools for any problems, you will find yourself writing unidiomatic code in your language to solve problems which are idiomatic in other languages. In the case where you’re forced to solve a problem in the wrong language, it may even be better sometimes to solve it in a way idiomatic to the more appropriate tool than heave and misapply your energy to an idiomatic but confusing solution. It certainly will be worth it for the affect on your brain.