I would argue that most of these are parsers and not compilers. While a compiler needs a parser, a compiler and a parser are not the same thing.
That said, even though I took a compilers class in college, I think my education was severely lacking in the value and use of parsers. I've seen so many problems that lend themselves well to some type of parser solved in some asinine, brute-force (often regex) method.
Try using Haskell's parsec. It's a combinatorial parser library. (While that may sound horrifying, it's actually a very sane way to write a parser and easy to understand.)
That said, even though I took a compilers class in college, I think my education was severely lacking in the value and use of parsers. I've seen so many problems that lend themselves well to some type of parser solved in some asinine, brute-force (often regex) method.