Representing an Abstract Syntax Tree in C

Question

I\'m implementing a compiler for a simple toy language in C. I have a working scanner and parser, and a reasonable background on the conceptual function/construction of an AST.

Answer 1

Ira Baxter gave you a good simple and forward looking answer, especially of note is the problems one will encounter down the road, so I will focus on this question:

Is there a better fourth option I haven't come across yet?

You are using the imperative language to write a compiler and having problems designing the data structure for the concept of a node in the AST. In the world of functional languages such as ML, OCaml, Haskell, F# one would use a Tagged union to hold all of the different node types in one data structure, which is basically what you have created.

I don't expect that the OP will switch to a functional language for this problem, but if others regularly deal with trees then they might find it of value to learn a functional language and use it for problems related to trees.