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1. readNatural :: ByteString -> Maybe (Natural, ByteString)

   bytestring	Data.ByteString.Char8

   readNatural reads a Natural number from the beginning of the ByteString. If there is no Natural number at the beginning of the string, it returns Nothing, otherwise it just returns the number read, and the rest of the string. readNatural does not ignore leading whitespace, the value must start with a decimal digit immediately at the beginning of the input string. Leading + signs are not accepted.

   Examples

   >>> readNatural "000111222333444555666777888999 all done"
   Just (111222333444555666777888999," all done")
   
   >>> readNatural "+000111222333444555666777888999 explicit sign"
   Nothing
   
   >>> readNatural "not a decimal number"
   Nothing
   

2. readWord :: ByteString -> Maybe (Word, ByteString)

   bytestring	Data.ByteString.Char8

   Try to read a Word value from the ByteString, returning Just (val, str) on success, where val is the value read and str is the rest of the input string. If the sequence of digits decodes to a value larger than can be represented by a Word, the returned value will be Nothing. readWord does not ignore leading whitespace, the value must start with a decimal digit immediately at the beginning of the input string. Leading + signs are not accepted.

   Examples

   >>> readWord "1729 sum of cubes"
   Just (1729," sum of cubes")
   
   >>> readWord "+1729 has an explicit sign"
   Nothing
   
   >>> readWord "not a decimal number"
   Nothing
   
   >>> readWord "98765432109876543210 overflows maxBound"
   Nothing
   

3. readWord16 :: ByteString -> Maybe (Word16, ByteString)

   bytestring	Data.ByteString.Char8

   A variant of readWord specialised to Word16.

4. readWord32 :: ByteString -> Maybe (Word32, ByteString)

   bytestring	Data.ByteString.Char8

   A variant of readWord specialised to Word32.

5. readWord64 :: ByteString -> Maybe (Word64, ByteString)

   bytestring	Data.ByteString.Char8

   A variant of readWord specialised to Word64.

6. readWord8 :: ByteString -> Maybe (Word8, ByteString)

   bytestring	Data.ByteString.Char8

   A variant of readWord specialised to Word8.

7. readFile :: FilePath -> IO ByteString

   bytestring	Data.ByteString.Lazy

   Read an entire file lazily into a ByteString. The Handle will be held open until EOF is encountered. Note that this function's implementation relies on hGetContents. The reader is advised to read its documentation.

8. readFile :: FilePath -> IO ByteString

   bytestring	Data.ByteString.Lazy.Char8

   Read an entire file lazily into a ByteString. The Handle will be held open until EOF is encountered. Note that this function's implementation relies on hGetContents. The reader is advised to read its documentation.

9. readInt :: ByteString -> Maybe (Int, ByteString)

   bytestring	Data.ByteString.Lazy.Char8

   Try to read a signed Int value from the ByteString, returning Just (val, str) on success, where val is the value read and str is the rest of the input string. If the sequence of digits decodes to a value larger than can be represented by an Int, the returned value will be Nothing. readInt does not ignore leading whitespace, the value must start immediately at the beginning of the input string.

   Examples

   >>> readInt "-1729 sum of cubes"
   Just (-1729," sum of cubes")
   
   >>> readInt "+1: readInt also accepts a leading '+'"
   Just (1, ": readInt also accepts a leading '+'")
   
   >>> readInt "not a decimal number"
   Nothing
   
   >>> readInt "12345678901234567890 overflows maxBound"
   Nothing
   
   >>> readInt "-12345678901234567890 underflows minBound"
   Nothing
   

10. readInt16 :: ByteString -> Maybe (Int16, ByteString)

    bytestring	Data.ByteString.Lazy.Char8

    A variant of readInt specialised to Int16.

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