Semantic Model (summary)


Make sure you have a semantic model worked out
Capture the meaning of your input language
Keep the model simple!
Translation is tricky without one
You won't get much typechecking either

Embed in native datatypes when possible
Lists, Strings, Tuples, Numbers, etc.
Variables
Functions

Make new types and constructors when necessary (or helpful)
Ocaml datatypes are recursive, branching, polymorphic
Very language-like
All user-visible errors will use your type names
Rename types when useful (eg: "file")