well this is now "valid" but idk what to do with it now actually i can ``match`` on this
```py type Arg = Flag | Concat | Pairs | Opt | Join type Program = dict[str, Arg] ghc: Program = dict( dynamic = Flag(), optimization_level = Concat("-O", Range(0, 2)), link_dirs = Pairs("-L", Path), link_libraries = Pairs("-l", Path), odir = Opt(ty=Path), hidir = Opt(ty=Path), output = Opt(Path, "-o"), sources = Join(ty=Path), ) ``` well time to make the codegen or something