-- $parsec
--
-- Compared to Parsec 3, attoparsec makes several tradeoffs.  It is
-- not intended for, or ideal for, all possible uses.
--
-- * While attoparsec can consume input incrementally, Parsec cannot.
--   Incremental input is a huge deal for efficient and secure network
--   and system programming, since it gives much more control to users
--   of the library over matters such as resource usage and the I/O
--   model to use.
--
-- * Much of the performance advantage of attoparsec is gained via
--   high-performance parsers such as 'I.takeWhile' and 'I.string'.
--   If you use complicated combinators that return lists of bytes or
--   characters, there is less performance difference between the two
--   libraries.
--
-- * Unlike Parsec 3, attoparsec does not support being used as a
--   monad transformer.
--
-- * attoparsec is specialised to deal only with strict 'B.ByteString'
--   input.  Efficiency concerns rule out both lists and lazy
--   bytestrings.  The usual use for lazy bytestrings would be to
--   allow consumption of very large input without a large footprint.
--   For this need, attoparsec's incremental input provides an
--   excellent substitute, with much more control over when input
--   takes place.  If you must use lazy bytestrings, see the
--   "Data.Attoparsec.ByteString.Lazy" module, which feeds lazy chunks
--   to a regular parser.
--
-- * Parsec parsers can produce more helpful error messages than
--   attoparsec parsers.  This is a matter of focus: attoparsec avoids
--   the extra book-keeping in favour of higher performance.

-- $incremental
--
-- attoparsec supports incremental input, meaning that you can feed it
-- a bytestring that represents only part of the expected total amount
-- of data to parse. If your parser reaches the end of a fragment of
-- input and could consume more input, it will suspend parsing and
-- return a 'T.Partial' continuation.
--
-- Supplying the 'T.Partial' continuation with a bytestring will
-- resume parsing at the point where it was suspended, with the
-- bytestring you supplied used as new input at the end of the
-- existing input. You must be prepared for the result of the resumed
-- parse to be another 'T.Partial' continuation.
--
-- To indicate that you have no more input, supply the 'T.Partial'
-- continuation with an empty bytestring.
--
-- Remember that some parsing combinators will not return a result
-- until they reach the end of input.  They may thus cause 'T.Partial'
-- results to be returned.
--
-- If you do not need support for incremental input, consider using
-- the 'I.parseOnly' function to run your parser.  It will never
-- prompt for more input.
--
-- /Note/: incremental input does /not/ imply that attoparsec will
-- release portions of its internal state for garbage collection as it
-- proceeds.  Its internal representation is equivalent to a single
-- 'ByteString': if you feed incremental input to a parser, it will
-- require memory proportional to the amount of input you supply.
-- (This is necessary to support arbitrary backtracking.)

-- $performance
--
-- If you write an attoparsec-based parser carefully, it can be
-- realistic to expect it to perform similarly to a hand-rolled C
-- parser (measuring megabytes parsed per second).
--
-- To actually achieve high performance, there are a few guidelines
-- that it is useful to follow.
--
-- Use the 'B.ByteString'-oriented parsers whenever possible,
-- e.g. 'I.takeWhile1' instead of 'many1' 'I.anyWord8'.  There is
-- about a factor of 100 difference in performance between the two
-- kinds of parser.
--
-- For very simple byte-testing predicates, write them by hand instead
-- of using 'I.inClass' or 'I.notInClass'.  For instance, both of
-- these predicates test for an end-of-line byte, but the first is
-- much faster than the second:
--
-- >endOfLine_fast w = w == 13 || w == 10
-- >endOfLine_slow   = inClass "\r\n"
--
-- Make active use of benchmarking and profiling tools to measure,
-- find the problems with, and improve the performance of your parser.

-- | Run a parser and print its result to standard output.
parseTest :: (Show a) => I.Parser a -> B.ByteString -> IO ()
parseTest p s = print (parse p s)
parseTest :: (Show a) => I.Parser a -> B.ByteString -> IO ()
parseTest p s = print (parse p s)
parseTest p s = print (parse p s)