ghc-exactprint

ExactPrint for GHC

Version on this page:0.5.1.0
LTS Haskell 24.56:1.10.0.0
Stackage Nightly 2026-08-24:1.12.0.0
Latest on Hackage:1.14.1.0

See all snapshots ghc-exactprint appears in

BSD-3-Clause licensed by Alan Zimmerman, Matthew Pickering
Maintained by [email protected]
This version can be pinned in stack with:ghc-exactprint-0.5.1.0@sha256:72587127a2c8877dd21e8355cd66af1eddf7bbaeb02926b2d4d27113a280c41a,5734

Module documentation for 0.5.1.0

  • Language
    • Language.Haskell
      • Language.Haskell.GHC
        • Language.Haskell.GHC.ExactPrint
          • Language.Haskell.GHC.ExactPrint.Annotate
          • Language.Haskell.GHC.ExactPrint.Delta
          • Language.Haskell.GHC.ExactPrint.GhcInterim
          • Language.Haskell.GHC.ExactPrint.Lookup
          • Language.Haskell.GHC.ExactPrint.Parsers
          • Language.Haskell.GHC.ExactPrint.Preprocess
          • Language.Haskell.GHC.ExactPrint.Print
          • Language.Haskell.GHC.ExactPrint.Transform
          • Language.Haskell.GHC.ExactPrint.Types
          • Language.Haskell.GHC.ExactPrint.Utils

Using the API Annotations available from GHC 7.10.2, this library provides a means to round trip any code that can be compiled by GHC, currently excluding lhs files.

It does this with a phased approach

  • Delta - converts GHC API Annotations into relative offsets, indexed by SrcSpan

  • Transform - functions to facilitate changes to the AST, adjusting the annotations generated in the Delta phase to suit the changes.

  • Print - converts an AST and its annotations to properly formatted source text.

Note: requires GHC 7.10.2 or later