Pdf.Core.XRef

Cross reference

Documentation

data XRef

Cross reference

Constructors

XRefTable Int64

Offset

XRefStream Int64 Stream

Offset and stream

Instances

Eq XRef

Defined in Pdf.Core.XRef

Methods

(==) :: XRef -> XRef -> Bool

(/=) :: XRef -> XRef -> Bool

Show XRef

Defined in Pdf.Core.XRef

Methods

showsPrec :: Int -> XRef -> ShowS

show :: XRef -> String

showList :: [XRef] -> ShowS

data Entry

Entry in cross reference stream

Constructors

EntryFree Int Int

Object number and generation

EntryUsed Int64 Int

Object offset (in bytes from the beginning of file) and generation

EntryCompressed Int Int

Object number of object stream and index within the object stream

Instances

Eq Entry

Defined in Pdf.Core.XRef

Methods

(==) :: Entry -> Entry -> Bool

(/=) :: Entry -> Entry -> Bool

Show Entry

Defined in Pdf.Core.XRef

Methods

showsPrec :: Int -> Entry -> ShowS

show :: Entry -> String

showList :: [Entry] -> ShowS

readXRef :: Buffer -> Int64 -> IO XRef

Read XRef at specified offset

lastXRef :: Buffer -> IO XRef

Find the last cross reference

prevXRef :: Buffer -> XRef -> IO (Maybe XRef)

Find prev cross reference

trailer :: Buffer -> XRef -> IO Dict

Read trailer for the xref

lookupTableEntry

Arguments

:: Buffer

-> XRef

should be xref table

-> Ref

indirect object to look for

-> IO (Maybe Entry)

Read xref entry for the indirect object from xref table

lookupStreamEntry

Arguments

:: Dict

xref stream dictionary

-> InputStream ByteString

decoded xref stream content

-> Ref

indirect object

-> IO (Maybe Entry)

Read xref entry for the indirect object from xref stream

See pdf1.7 spec: 7.5.8 Cross-Reference Streams. May throw UnknownXRefStreamEntryType

isTable :: InputStream ByteString -> IO Bool

Check whether the stream starts with "xref" keyword. The keyword itself and newline after it are consumed

data UnknownXRefStreamEntryType

Unknown entry type should be interpreted as reference to null object

Constructors

UnknownXRefStreamEntryType Int

Instances

Show UnknownXRefStreamEntryType

Defined in Pdf.Core.XRef

Methods

showsPrec :: Int -> UnknownXRefStreamEntryType -> ShowS

show :: UnknownXRefStreamEntryType -> String

showList :: [UnknownXRefStreamEntryType] -> ShowS

Exception UnknownXRefStreamEntryType

Defined in Pdf.Core.XRef

Methods

toException :: UnknownXRefStreamEntryType -> SomeException

fromException :: SomeException -> Maybe UnknownXRefStreamEntryType

displayException :: UnknownXRefStreamEntryType -> String