The P programming language

Some ideas for a new programming language for Plan 9.

Desidarata:

• Straightforward compilation to C
• Reasonably interoperable with C
• Type inference
• Parametric types
• Namespaces
• Tuple types (shorthand for structs)
• Tagged unions
• Pattern matching
• Closures (compiles to the classic void * aux argument); probably a bit clumsy

Questions:

• How much of this could be implemented by a smart macro system? Having a simple meta language to implement these things could simplify the compiler.
• Extend C's syntax, supplement it with a new one or replace it altogether?