Meta-programming with well-typed code analysis

Structure-analyzing metaprograms remain largely type-unsafe. In programming languages that support meta-programming, the type system is not strong enough to guarantee that well-typed metaprograms produce only well-typed programs. Banning facilities for code analysis from the meta-programming toolbox in order to achieve type soundness, robs programmers of useful tools such as ability to specify powerful code transformations. We present code pattern types, types that reason about the structure of programs through pattern matching and supports type safe code analysis.