The program is the database is the interface

What the author demonstrates here is a powerful principle that dates back to LISP's origins but remains revolutionary today: the collapse of artificial boundaries between program, data, and interface creates a more direct connection to the problem domain. This example elegantly shows how a few dozen lines of Clojure can replace an entire accounting application. The transactions live directly in the code, the categorization rules are simple pattern matchers, and the "interface" is just printed output of the…

Since its inception, computers were based on the model of a machine traversed by data that are processed like sausages in a mincer, as data was fed directly on hardware which had code assembled as physical wires. However, the software part of the machines is made of the same material as the data, so they are much closer to what current programming languages seem to imply. It is natural that they tend to converge, especially in Lisp-like languages, into a…