Lambda the Ultimate

What is a programming language? The common definition generally only includes the syntax and semantics of, for lack of a better description, the “text” of a program. For instance, we think of languages as defining how variables are declared, how loops are specified, functions defined, if certain mechanisms like continuations or closures are first-class (or close to it), etc.

This definition fails to capture how the languages are really used, though. Just because a handy library is written in C++ doesn’t mean it will integrate nicely into my present C++ program. The reason is that it is the APIs that are the real language - not the obscure rules that define what a loop looks like or which characters are allowed in a variable name.

I realize this is a (potentially mis-informed) blog post (from my own blog, no less), but I'm not familiar enough with the research to know if this phenomenon has been widely studied or not. (And if so, where I can read more about it.)

In my experience, the integration of multiple libraries with different styles is one of the primary reasons large programs often devolve into an incomprehensible mess over time. It's not the only reason, of course, but I think it contributes - especially when some programmers on the team are more familiar with one library vs. another, etc.

What could be done in the context of a programming language to mitigate this? Or, what has been done? It doesn't seem like the mainstream languages are very good at keeping this problem at bay. (Or is it perhaps not a problem for anyone but me?)