My first fifteen compilers
Favorite quote:<p>> There’s a wealth of tutorials, courses, books, and the like about how to write compilers. But if somebody believes that writing a transpiler isn’t fundamentally the same thing as writing a compiler, it may not occur to them to look at any of that material.<p>The basic argument is this: "compiler" isn't a term that needs  to be limited from transforming a high-level input to a low-level output. Any program which is structured to map an AST to another AST, no matter the relative levels of abstraction, can borrow from many of the principles of modern compiler theory, including using many small passes rather than monolithic rewrites.<p>At a company I worked for, we compiled a high-level declarative expression language of our own devising into SQL and other back-end representations, including English. Is that a "compiler" as many see it? No. However, thinking about the problem like a compiler problem gave us lots of insights into how to architect our product; it let us draw on an existing wealth of knowledge to make improvements quickly and reliably.