ghc-syb-0.1.2.1: SYB instances for the GHC APISource codeContentsIndex
GHC.SYB.Utils
Description

GHC.Syb.Utils provides common utilities for the Ghc Api, either based on Data/Typeable or for use with Data.Generics over Ghc Api types.

example output of showData on parsedSource, renamedSource, and typecheckedSource for a trivial HelloWorld module, compared with ppr output:

------------------------- pretty-printed parsedSource
module HelloWorld where
main = putStrLn Hello, World!
------------------------- pretty-printed renamedSource
Just (HelloWorld.main = System.IO.putStrLn Hello, World!,
      [import Prelude],
      Nothing,
      Nothing,

(HaddockModInfo
 (Nothing)
 (Nothing)
 (Nothing)
 (Nothing)))
------------------------- pretty-printed typecheckedSource
Just <AbsBinds [] [] [HelloWorld.main <= [] main]
        HelloWorld.main :: GHC.IOBase.IO ()
        []
        { main = System.IO.putStrLn Hello, World! }>
------------------------- shown parsedSource

(L {HelloWorld.hs:1:0}
 (HsModule
  (Just
   (L {HelloWorld.hs:1:7-16} {ModuleName: HelloWorld}))
  (Nothing)
  []
  [
   (L {HelloWorld.hs:2:0-30}
    (ValD
     (FunBind
      (L {HelloWorld.hs:2:0-3}
       (Unqual {OccName: main}))
      (False)
      (MatchGroup
       [
        (L {HelloWorld.hs:2:0-30}
         (Match
          []
          (Nothing)
          (GRHSs
           [
            (L {HelloWorld.hs:2:7-30}
             (GRHS
              []
              (L {HelloWorld.hs:2:7-30}
               (HsApp
                (L {HelloWorld.hs:2:7-14}
                 (HsVar
                  (Unqual {OccName: putStrLn})))
                (L {HelloWorld.hs:2:16-30}
                 (HsLit
                  (HsString {FastString: Hello, World!})))))))]
           (EmptyLocalBinds))))] {!type placeholder here?!})
      (WpHole) {!NameSet placeholder here!}
      (Nothing))))]
  (Nothing)
  (HaddockModInfo
   (Nothing)
   (Nothing)
   (Nothing)
   (Nothing))
  (Nothing)))
------------------------- shown renamedSource

((,,,,)
 (HsGroup
  (ValBindsOut
   [
    ((,)
     (NonRecursive) {Bag(Located (HsBind Name)):
     [
      (L {HelloWorld.hs:2:0-30}
       (FunBind
        (L {HelloWorld.hs:2:0-3} {Name: HelloWorld.main})
        (False)
        (MatchGroup
         [
          (L {HelloWorld.hs:2:0-30}
           (Match
            []
            (Nothing)
            (GRHSs
             [
              (L {HelloWorld.hs:2:7-30}
               (GRHS
                []
                (L {HelloWorld.hs:2:7-30}
                 (HsApp
                  (L {HelloWorld.hs:2:7-14}
                   (HsVar {Name: System.IO.putStrLn}))
                  (L {HelloWorld.hs:2:16-30}
                   (HsLit
                    (HsString {FastString: Hello, World!})))))))]
             (EmptyLocalBinds))))] {!type placeholder here?!})
        (WpHole) {NameSet:
        [{Name: System.IO.putStrLn}]}
        (Nothing)))]})]
   [])
  []
  []
  []
  []
  []
  []
  []
  []
  [])
 [
  (L {Implicit import declaration}
   (ImportDecl
    (L {Implicit import declaration} {ModuleName: Prelude})
    (False)
    (False)
    (Nothing)
    (Nothing)))]
 (Nothing)
 (Nothing)
 (HaddockModInfo
  (Nothing)
  (Nothing)
  (Nothing)
  (Nothing)))
------------------------- shown typecheckedSource
{Bag(Located (HsBind Var)):
[
 (L {HelloWorld.hs:2:0-30}
  (AbsBinds
   []
   []
   [
    ((,,,)
     [] {Var: HelloWorld.main} {Var: main}
     [])] {Bag(Located (HsBind Var)):
   [
    (L {HelloWorld.hs:2:0-30}
     (FunBind
      (L {HelloWorld.hs:2:0-3} {Var: main})
      (False)
      (MatchGroup
       [
        (L {HelloWorld.hs:2:0-30}
         (Match
          []
          (Nothing)
          (GRHSs
           [
            (L {HelloWorld.hs:2:7-30}
             (GRHS
              []
              (L {HelloWorld.hs:2:7-30}
               (HsApp
                (L {HelloWorld.hs:2:7-14}
                 (HsVar {Var: System.IO.putStrLn}))
                (L {HelloWorld.hs:2:16-30}
                 (HsLit
                  (HsString {FastString: Hello, World!})))))))]
           (EmptyLocalBinds))))] GHC.IOBase.IO ())
      (WpHole) {!NameSet placeholder here!}
      (Nothing)))]}))]}
Synopsis
data Stage
= Parser
| Renamer
| TypeChecker
showData :: Data a => Stage -> Int -> a -> String
everythingStaged :: Stage -> (r -> r -> r) -> r -> GenericQ r -> GenericQ r
everythingBut :: GenericQ Bool -> (r -> r -> r) -> r -> GenericQ r -> GenericQ r
Documentation
data Stage Source
Ghc Ast types tend to have undefined holes, to be filled by later compiler phases. We tag Asts with their source, so that we can avoid such holes based on who generated the Asts.
Constructors
Parser
Renamer
TypeChecker
show/hide Instances
showData :: Data a => Stage -> Int -> a -> StringSource
Generic Data-based show, with special cases for GHC Ast types, and simplistic indentation-based layout (the Int parameter); showing abstract types abstractly and avoiding known potholes (based on the Stage that generated the Ast)
everythingStaged :: Stage -> (r -> r -> r) -> r -> GenericQ r -> GenericQ rSource
Like everything, but avoid known potholes, based on the Stage that generated the Ast.
everythingBut :: GenericQ Bool -> (r -> r -> r) -> r -> GenericQ r -> GenericQ rSource
A variation of everything, using a 'GenericQ Bool' to skip parts of the input Data.
Produced by Haddock version 2.4.2