Question

I have decided to write a small interpreter as my next project, in Ruby. What knowledge/skills will I need to have to be successful?
I haven’t decided on the language to interpret yet, but I am looking for something that is not a toy language, but would be relatively easy to write an interpreter for.
Thanks in advance.

Answer 1

You will have to learn at least:

• lexical analysis (grouping characters into tokens)
• parsing (grouping tokens together into structure)
• abstract syntax trees (representing program structure in a data structure)
• data representation (assuming your language will have variables)
• an evaluation loop that “runs” your program

An excellent introduction to some of these topics can be found in the introductory text Structure and Interpretation of Computer Programs. The language used in that book is Scheme, which is a robust, well-specified language that is ideally suited for your first interpreter implementation. Highly recommended.