- something that takes your code, and converts it into a syntax tree
- it has nodes that describe what’s happening in your program
- each node has a type and some other arbitrary data
- almost everything uses ASTs under the hood
- review the “Visitor pattern”
- syntax trees are complex, is very important to know your node types well in order to work with them.
- “Making easy things easy, and hard things possible” — fron the book “Learning Perl”