Hi there, I use llvm package for building compiler for a small C-like language and it have some problems with high-level interface that package provides. I use simple scheme: [parser] -> (untyped AST) -> [analyser] -> (typed AST) -> [LLVM] -> (object code). At first, as I want to use high-level interface, typed AST must satisfy all needed class constraints. For simple types and operations this can be solved by adding neccessary constraints to the corresponding definitions. But it's not very good solution, because in general typed AST can represent high-level data structures, that would have certain representation, known when generating code, but not checking logic. Problem becomes much more complex when I want to add function calls into my language. Type class CallArgs has an instance CallArgs (IO a) (CodeGenFunction r (Value a)), which can't be given as a constraint in typed AST because of free variable r. For a long time I have had no idea of how I can add function calls into my language. The only solution I see at the moment is to reject high-level llvm interface provided by llvm library and use directly FFI bindings to C. But I can't get rid of feeling that I'm missing something or doing all stuff totally wrong. It would be great if someone, who has experience in using high-level interface to LLVM for building a compiler, could help me. Thanks in advance, Nick