Safe Haskell  None 

Language  Haskell2010 
This module is currently under heavy development, and no promises are made about API stability. Use with care.
We welcome any feedback / contributions on this, as it is the main point of the library.
 type Transform = TransformT Identity
 newtype TransformT m a = TransformT {
 runTransformT :: RWST () [String] (Anns, Int) m a
 runTransform :: Anns > Transform a > (a, (Anns, Int), [String])
 runTransformFrom :: Int > Anns > Transform a > (a, (Anns, Int), [String])
 runTransformFromT :: Monad m => Int > Anns > TransformT m a > m (a, (Anns, Int), [String])
 logTr :: Monad m => String > TransformT m ()
 logDataWithAnnsTr :: Monad m => Data a => String > a > TransformT m ()
 getAnnsT :: Monad m => TransformT m Anns
 putAnnsT :: Monad m => Anns > TransformT m ()
 modifyAnnsT :: Monad m => (Anns > Anns) > TransformT m ()
 uniqueSrcSpanT :: Transform SrcSpan
 cloneT :: (Data a, Typeable a) => a > Transform (a, [(SrcSpan, SrcSpan)])
 getEntryDPT :: Data a => Located a > Transform DeltaPos
 setEntryDPT :: Data a => Located a > DeltaPos > Transform ()
 transferEntryDPT :: (Data a, Data b) => Located a > Located b > Transform ()
 setPrecedingLinesDeclT :: LHsDecl RdrName > Int > Int > Transform ()
 setPrecedingLinesT :: Data a => Located a > Int > Int > Transform ()
 addSimpleAnnT :: Data a => Located a > DeltaPos > [(KeywordId, DeltaPos)] > Transform ()
 addTrailingCommaT :: Data a => Located a > Transform ()
 removeTrailingCommaT :: Data a => Located a > Transform ()
 class Monad m => HasTransform m where
 class Data t => HasDecls t where
 hsDecls :: Monad m => t > TransformT m [LHsDecl RdrName]
 replaceDecls :: Monad m => t > [LHsDecl RdrName] > TransformT m t
 hasDeclsSybTransform :: (Data t2, Typeable t2, Monad m) => (forall t. HasDecls t => t > m t) > (LHsBind RdrName > m (LHsBind RdrName)) > t2 > m t2
 hsDeclsGeneric :: (Data t, Typeable t) => t > Transform [LHsDecl RdrName]
 hsDeclsPatBind :: Monad m => LHsBind RdrName > TransformT m [LHsDecl RdrName]
 hsDeclsPatBindD :: Monad m => LHsDecl RdrName > TransformT m [LHsDecl RdrName]
 replaceDeclsPatBind :: Monad m => LHsBind RdrName > [LHsDecl RdrName] > TransformT m (LHsBind RdrName)
 replaceDeclsPatBindD :: Monad m => LHsDecl RdrName > [LHsDecl RdrName] > TransformT m (LHsDecl RdrName)
 modifyDeclsT :: (HasDecls t, HasTransform m) => ([LHsDecl RdrName] > m [LHsDecl RdrName]) > t > m t
 modifyValD :: forall m t. HasTransform m => SrcSpan > Decl > (Match > [Decl] > m ([Decl], Maybe t)) > m (Decl, Maybe t)
 hsDeclsValBinds :: Monad m => HsLocalBinds RdrName > TransformT m [LHsDecl RdrName]
 replaceDeclsValbinds :: Monad m => HsLocalBinds RdrName > [LHsDecl RdrName] > TransformT m (HsLocalBinds RdrName)
 insertAtStart :: (Data ast, HasDecls (Located ast)) => Located ast > LHsDecl RdrName > Transform (Located ast)
 insertAtEnd :: (Data ast, HasDecls (Located ast)) => Located ast > LHsDecl RdrName > Transform (Located ast)
 insertAfter :: (Data ast, HasDecls (Located ast)) => Located old > Located ast > LHsDecl RdrName > Transform (Located ast)
 insertBefore :: (Data ast, HasDecls (Located ast)) => Located old > Located ast > LHsDecl RdrName > Transform (Located ast)
 balanceComments :: (Data a, Data b) => Located a > Located b > Transform ()
 balanceTrailingComments :: Monad m => (Data a, Data b) => Located a > Located b > TransformT m [(Comment, DeltaPos)]
 moveTrailingComments :: (Data a, Data b) => Located a > Located b > Transform ()
 captureOrder :: Data a => Located a > [Located b] > Anns > Anns
 captureOrderAnnKey :: AnnKey > [Located b] > Anns > Anns
 isUniqueSrcSpan :: SrcSpan > Bool
 mergeAnns :: Anns > Anns > Anns
 mergeAnnList :: [Anns] > Anns
 setPrecedingLinesDecl :: LHsDecl RdrName > Int > Int > Anns > Anns
 setPrecedingLines :: Data a => Located a > Int > Int > Anns > Anns
 getEntryDP :: Data a => Anns > Located a > DeltaPos
 setEntryDP :: Data a => Located a > DeltaPos > Anns > Anns
 transferEntryDP :: (Data a, Data b) => Located a > Located b > Anns > Anns
 addTrailingComma :: Data a => Located a > DeltaPos > Anns > Anns
 wrapSig :: LSig RdrName > LHsDecl RdrName
 wrapDecl :: LHsBind RdrName > LHsDecl RdrName
 decl2Sig :: LHsDecl name > [LSig name]
 decl2Bind :: LHsDecl name > [LHsBind name]
The Transform Monad
type Transform = TransformT Identity Source
Monad type for updating the AST and managing the annotations at the same time. The W state is used to generate logging information if required.
newtype TransformT m a Source
Monad transformer version of Transform
monad
TransformT  

Monad m => MonadReader () (TransformT m) Source  
Monad m => Monad (TransformT m) Source  
Functor m => Functor (TransformT m) Source  
Monad m => Applicative (TransformT m) Source  
HasTransform (TransformT Identity) Source  
Monad m => MonadWriter [String] (TransformT m) Source  
Monad m => MonadState (Anns, Int) (TransformT m) Source 
runTransformFromT :: Monad m => Int > Anns > TransformT m a > m (a, (Anns, Int), [String]) Source
Run a monad transformer stack for the TransformT
monad transformer
Transform monad operations
logTr :: Monad m => String > TransformT m () Source
Log a string to the output of the Monad
logDataWithAnnsTr :: Monad m => Data a => String > a > TransformT m () Source
Log a representation of the given AST with annotations to the output of the Monad
getAnnsT :: Monad m => TransformT m Anns Source
Access the Anns
being modified in this transformation
modifyAnnsT :: Monad m => (Anns > Anns) > TransformT m () Source
Change the stored Anns
cloneT :: (Data a, Typeable a) => a > Transform (a, [(SrcSpan, SrcSpan)]) Source
Make a copy of an AST element, replacing the existing SrcSpans with new ones, and duplicating the matching annotations.
getEntryDPT :: Data a => Located a > Transform DeltaPos Source
Transform
monad version of getEntryDP
setEntryDPT :: Data a => Located a > DeltaPos > Transform () Source
Transform
monad version of getEntryDP
transferEntryDPT :: (Data a, Data b) => Located a > Located b > Transform () Source
Transform
monad version of transferEntryDP
setPrecedingLinesDeclT :: LHsDecl RdrName > Int > Int > Transform () Source
Transform
monad version of setPrecedingLinesDecl
setPrecedingLinesT :: Data a => Located a > Int > Int > Transform () Source
Transform
monad version of setPrecedingLines
addSimpleAnnT :: Data a => Located a > DeltaPos > [(KeywordId, DeltaPos)] > Transform () Source
Create a simple Annotation
without comments, and attach it to the first
parameter.
addTrailingCommaT :: Data a => Located a > Transform () Source
Add a trailing comma annotation, unless there is already one
removeTrailingCommaT :: Data a => Located a > Transform () Source
Remove a trailing comma annotation, if there is one one
Managing declarations, in Transform monad
class Monad m => HasTransform m where Source
Used to integrate a Transform
into other Monad stacks
class Data t => HasDecls t where Source
Provide a means to get and process the immediate child declartions of a given AST element.
hsDecls :: Monad m => t > TransformT m [LHsDecl RdrName] Source
Return the HsDecl
s that are directly enclosed in the
given syntax phrase. They are always returned in the wrapped HsDecl
form, even if orginating in local decls. This is safe, as annotations
never attach to the wrapper, only to the wrapped item.
replaceDecls :: Monad m => t > [LHsDecl RdrName] > TransformT m t Source
Replace the directly enclosed decl list by the given
decl list. Runs in the Transform
monad to be able to update list order
annotations, and rebalance comments and other layout changes as needed.
For example, a call on replaceDecls for a wrapped FunBind
having no
where clause will convert
 This is a function foo = x  comment1
in to
 This is a function foo = x  comment1 where nn = 2
:: (Data t2, Typeable t2, Monad m)  
=> (forall t. HasDecls t => t > m t)  Worker function for the general case 
> (LHsBind RdrName > m (LHsBind RdrName))  Worker function for FunBind/PatBind 
> t2  Item to be updated 
> m t2 
Do a transformation on an AST fragment by providing a function to process
the general case and one specific for a LHsBind
. This is required
because a FunBind
may have multiple Match
items, so we cannot
gurantee that replaceDecls
after hsDecls
is idempotent.
hsDeclsPatBind :: Monad m => LHsBind RdrName > TransformT m [LHsDecl RdrName] Source
Extract the immediate declarations for a PatBind
. This
cannot be a member of HasDecls
because a FunBind
is not idempotent
for hsDecls
/ replaceDecls
. hsDeclsPatBind
/ replaceDeclsPatBind
is
idempotent.
hsDeclsPatBindD :: Monad m => LHsDecl RdrName > TransformT m [LHsDecl RdrName] Source
Extract the immediate declarations for a PatBind
wrapped in a ValD
. This
cannot be a member of HasDecls
because a FunBind
is not idempotent
for hsDecls
/ replaceDecls
. hsDeclsPatBindD
/ replaceDeclsPatBindD
is
idempotent.
replaceDeclsPatBind :: Monad m => LHsBind RdrName > [LHsDecl RdrName] > TransformT m (LHsBind RdrName) Source
Replace the immediate declarations for a PatBind
. This
cannot be a member of HasDecls
because a FunBind
is not idempotent
for hsDecls
/ replaceDecls
. hsDeclsPatBind
/ replaceDeclsPatBind
is
idempotent.
replaceDeclsPatBindD :: Monad m => LHsDecl RdrName > [LHsDecl RdrName] > TransformT m (LHsDecl RdrName) Source
Replace the immediate declarations for a PatBind
wrapped in a ValD
. This
cannot be a member of HasDecls
because a FunBind
is not idempotent
for hsDecls
/ replaceDecls
. hsDeclsPatBindD
/ replaceDeclsPatBindD
is
idempotent.
modifyDeclsT :: (HasDecls t, HasTransform m) => ([LHsDecl RdrName] > m [LHsDecl RdrName]) > t > m t Source
Apply a transformation to the decls contained in t
modifyValD :: forall m t. HasTransform m => SrcSpan > Decl > (Match > [Decl] > m ([Decl], Maybe t)) > m (Decl, Maybe t) Source
Utility, does not manage layout
hsDeclsValBinds :: Monad m => HsLocalBinds RdrName > TransformT m [LHsDecl RdrName] Source
Utility function for extracting decls from HsLocalBinds
. Use with
care, as this does not necessarily return the declarations in order, the
ordering should be done by the calling function from the HsLocalBinds
context in the AST.
replaceDeclsValbinds :: Monad m => HsLocalBinds RdrName > [LHsDecl RdrName] > TransformT m (HsLocalBinds RdrName) Source
Utility function for returning decls to HsLocalBinds
. Use with
care, as this does not manage the declaration order, the
ordering should be done by the calling function from the HsLocalBinds
context in the AST.
Managing lists, Transform monad
insertAtStart :: (Data ast, HasDecls (Located ast)) => Located ast > LHsDecl RdrName > Transform (Located ast) Source
Insert a declaration at the beginning or end of the subdecls of the given AST item
insertAtEnd :: (Data ast, HasDecls (Located ast)) => Located ast > LHsDecl RdrName > Transform (Located ast) Source
Insert a declaration at the beginning or end of the subdecls of the given AST item
insertAfter :: (Data ast, HasDecls (Located ast)) => Located old > Located ast > LHsDecl RdrName > Transform (Located ast) Source
Insert a declaration at a specific location in the subdecls of the given AST item
insertBefore :: (Data ast, HasDecls (Located ast)) => Located old > Located ast > LHsDecl RdrName > Transform (Located ast) Source
Insert a declaration at a specific location in the subdecls of the given AST item
Low level operations used in HasDecls
balanceComments :: (Data a, Data b) => Located a > Located b > Transform () Source
The relatavise phase puts all comments appearing between the end of one AST
item and the beginning of the next as annPriorComments
for the second one.
This function takes two adjacent AST items and moves any annPriorComments
from the second one to the annFollowingComments
of the first if they belong
to it instead. This is typically required before deleting or duplicating
either of the AST elements.
balanceTrailingComments :: Monad m => (Data a, Data b) => Located a > Located b > TransformT m [(Comment, DeltaPos)] Source
After moving an AST element, make sure any comments that may belong with the following element in fact do. Of necessity this is a heuristic process, to be tuned later. Possibly a variant should be provided with a passedin decision function.
moveTrailingComments :: (Data a, Data b) => Located a > Located b > Transform () Source
Move any annFollowingComments
values from the Annotation
associated to
the first parameter to that of the second.
Managing lists, pure functions
captureOrder :: Data a => Located a > [Located b] > Anns > Anns Source
If a list has been reordered or had items added, capture the new order in
the appropriate annSortKey
attached to the Annotation
for the first
parameter.
captureOrderAnnKey :: AnnKey > [Located b] > Anns > Anns Source
If a list has been reordered or had items added, capture the new order in
the appropriate annSortKey
item of the supplied AnnKey
Operations
isUniqueSrcSpan :: SrcSpan > Bool Source
Test whether a given SrcSpan
was generated by uniqueSrcSpanT
Pure functions
mergeAnnList :: [Anns] > Anns Source
Combine a list of annotations
setPrecedingLinesDecl :: LHsDecl RdrName > Int > Int > Anns > Anns Source
Unwrap a HsDecl and call setPrecedingLines on it ++AZ++ TODO: get rid of this, it is a synonym only
setPrecedingLines :: Data a => Located a > Int > Int > Anns > Anns Source
Adjust the entry annotations to provide an n
line preceding gap
transferEntryDP :: (Data a, Data b) => Located a > Located b > Anns > Anns Source
Take the annEntryDelta associated with the first item and associate it with the second. Also transfer any comments occuring before it.