@hackage / syntax-trees

Provides an instance that translates haskell-src-exts expression trees into Template Haskell expression trees in a way that depends only on the haskell-src-exts syntax tree and agreement on the pretty-printed representation of Haskell between haskell-src-exts pretty-printer and Template Haskell quotations (as opposed to depending on both TH and haskell-src-exts syntax tree representations).

Instead of converting between data types, haskell-src-exts syntax trees are pretty-printed and wrapped in a TH quotation which is then interpreted as a Haskell program, yielding a TH Exp tree. Free variables in the haskell-src-exts tree are preserved by lifting them to TH splices prior to pretty-printing.