Skimming through the first chapters of the book I can say it doesn't seem to assume any prior knowledge of C or even a background in programming, it explains all the basic concepts (conditionals, types etc...)
That being said I'm not entirely convinced that implementing a programming language is the best toy project for learning C since one of the first things you have to write is a parser and we all know string handling in C is a pity.
That being said it looks very interesting, I know C quite well but I might read it for the "implementing lisp" parts.
Author here. Actually a parser combinator library is used for the parsing. As you mention, I think there should be some interesting things inside for people with any experience in C.
That being said I'm not entirely convinced that implementing a programming language is the best toy project for learning C since one of the first things you have to write is a parser and we all know string handling in C is a pity.
That being said it looks very interesting, I know C quite well but I might read it for the "implementing lisp" parts.