To give a concrete example of what we're talking about, I wrote this a couple of months ago in a similar discussion: https://news.ycombinator.com/item?id=263205

To give a concrete example of what we're talking about, I wrote this a couple of months ago in a similar discussion: https://news.ycombinator.com/item?id=26320573 https://news.ycombinator.com/item?id=26320573 The problem is that "Compose" function is essentially impossible to write. I say essentially because it's probably something that could theoretically be written, but not with any reasonable amount of effort. It would literally be on par with the difficulty of implementing a DB from scratch that implements the Logica language as its base query language.