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> how it can turn recursive structures like expressions and statement blocks into linear sequences of instructions

I think this is one of the key concepts in a compiler, yet I don't think it has much to do with parsing.

Parsing (in a compiler) is the act of taking a linear sequence of characters or tokens, and turning them into a rich AST structure.

The back end of the compiler is what takes this recursive structure and flattens it out into a linear sequence of instructions that "mean" the same thing as the tree.

Parsing is critical, of course, for building a working compiler. But I think not focusing on surface syntax gets to the key recursive-to-linear insight you mention more directly!

> and turning them into a rich AST structure.

This is not a necessary step, and is specifically not done in a lot of simpler compilers. E.g. most "Wirth-type" compilers never build an AST.

There are lots of good reasons to build ASTs if you want to do complex analysis and optimisation, and it simplifies the presentation of some things, but calling the code generator module straight from the parser in many ways makes the direction connection clearer.

effectively bypassing the whole process of parsing... which IMHO is half the fun of writing a compiler

Fun for compiler writers, perhaps ;) I am a big fan of languages with minimal syntax because complicated grammar affects the user as well. The machine may do the hard work of translating the source code, but the user still has to do some degree of translation of their own in their head while reading it.

I view source code as a kind of interface, and I like simple, clean interfaces.

>> It's interesting to note that Jack doesn't specialise in compilers, nor computer science for that matter, yet his explanations are far clearer to me than many of those who do.

Yes. It's written with a practical approach in mind. Once you get that idea, feel free to study compiler textbooks like "the Dragon Book",for example, for in-depth theory.

I halfway agree with you, but with the caveat that parsing has been done to death, while dealing with the lower level aspects often gets glossed over.