Language.Haskell.GHC.ExactPrint.Utils

Manipulating Positons

ss2pos :: SrcSpan -> Pos

ss2posEnd :: SrcSpan -> Pos

undelta :: Pos -> DeltaPos -> LayoutStartCol -> Pos

Apply the delta to the current position, taking into account the current column offset if advancing to a new line

isPointSrcSpan :: SrcSpan -> Bool

Checks whether a SrcSpan has zero length.

pos2delta :: Pos -> Pos -> DeltaPos

Convert the start of the second Pos to be an offset from the first. The assumption is the reference starts before the second Pos

ss2delta :: Pos -> SrcSpan -> DeltaPos

Create a delta from the current position to the start of the given SrcSpan.

addDP :: DeltaPos -> DeltaPos -> DeltaPos

Add together two DeltaPos taking into account newlines

DP (0, 1) `addDP` DP (0, 2) == DP (0, 3)
DP (0, 9) `addDP` DP (1, 5) == DP (1, 5)
DP (1, 4) `addDP` DP (1, 3) == DP (2, 3)

spanLength :: SrcSpan -> Int

isGoodDelta :: DeltaPos -> Bool

A good delta has no negative values.

Manipulating Comments

mkComment :: String -> SrcSpan -> Comment

mkKWComment :: AnnKeywordId -> SrcSpan -> Comment

Makes a comment which originates from a specific keyword.

dpFromString :: String -> DeltaPos

Calculates the distance from the start of a string to the end of a string.

comment2dp :: (Comment, DeltaPos) -> (KeywordId, DeltaPos)

GHC Functions

srcSpanStartLine :: SrcSpan -> Int

srcSpanEndLine :: SrcSpan -> Int

srcSpanStartColumn :: SrcSpan -> Int

srcSpanEndColumn :: SrcSpan -> Int

rdrName2String :: RdrName -> String

isSymbolRdrName :: RdrName -> Bool

tokComment :: Located AnnotationComment -> Comment

isListComp :: HsStmtContext name -> Bool

Manipulating Annotations

getAnnotationEP :: Data a => Located a -> Anns -> Maybe Annotation

annTrueEntryDelta :: Annotation -> DeltaPos

The "true entry" is the distance from the last concrete element to the start of the current element.

annCommentEntryDelta :: Annotation -> DeltaPos -> DeltaPos

Take an annotation and a required "true entry" and calculate an equivalent one relative to the last comment in the annPriorComments.

annLeadingCommentEntryDelta :: Annotation -> DeltaPos

Return the DP of the first item that generates output, either a comment or the entry DP

General Utility

orderByKey :: [(SrcSpan, a)] -> [SrcSpan] -> [a]

Given a list of items and a list of keys, returns a list of items ordered by their position in the list of keys.

For tests

debug :: c -> String -> c

Provide a version of trace the comes at the end of the line, so it can easily be commented out when debugging different things.

debugM :: Monad m => String -> m ()

warn :: c -> String -> c

showGhc :: Outputable a => a -> String

Show a GHC.Outputable structure

showAnnData :: Data a => Anns -> Int -> a -> String

Show a GHC AST with interleaved Annotation information.

ghead :: String -> [a] -> a

glast :: String -> [a] -> a

gtail :: String -> [a] -> [a]

gfromJust :: String -> Maybe a -> a