Dynamic loading of Haskell abstract syntax expression

Question

Can we use GHC API or something else to load not text source modules, but AST expressions, similar to haskell-src-exts Exp type? This way we could save time for code generation and parsing.

Answer 1

I don't think the GHC API exposes an AST interface (could be wrong though), but Template Haskell does. If you build expressions using the Language.Haskell.TH Exp structure, you can create functions/declarations and make use of them by the $(someTHFunction) syntax.

A fairly major caveat is that TH only runs at compile time, so you would need to pre-generate everything. If you want to use TH at run-time, I think you'd need to pretty-print the template haskell AST, then use the GHC API on the resulting string.