Data.Text.Internal.Fusion

Copyright	(c) Tom Harper 2008-2009 (c) Bryan O'Sullivan 2009-2010 (c) Duncan Coutts 2009
License	BSD-style
Maintainer	[email protected]
Stability	experimental
Portability	GHC
Safe Haskell	None
Language	Haskell2010

Types

data Stream a Source

data Step s a Source

Intermediate result in a processing pipeline.

Creation and elimination

stream :: Text -> Stream Char Source

O(n) Convert a Text into a 'Stream Char'.

unstream :: Stream Char -> Text Source

O(n) Convert a 'Stream Char' into a Text.

reverseStream :: Text -> Stream Char Source

O(n) Convert a Text into a 'Stream Char', but iterate backwards.

length :: Stream Char -> Int Source

Transformations

reverse :: Stream Char -> Text Source

O(n) Reverse the characters of a string.

Construction

Scans

reverseScanr :: (Char -> Char -> Char) -> Char -> Stream Char -> Stream Char Source

O(n) Perform the equivalent of scanr over a list, only with the input and result reversed.

Accumulating maps

mapAccumL :: (a -> Char -> (a, Char)) -> a -> Stream Char -> (a, Text) Source

O(n) Like a combination of map and foldl'. Applies a function to each element of a Text, passing an accumulating parameter from left to right, and returns a final Text.

Generation and unfolding

unfoldrN :: Int -> (a -> Maybe (Char, a)) -> a -> Stream Char Source

O(n) Like unfoldr, unfoldrN builds a stream from a seed value. However, the length of the result is limited by the first argument to unfoldrN. This function is more efficient than unfoldr when the length of the result is known.

Indexing

index :: Stream Char -> Int -> Char Source

O(n) stream index (subscript) operator, starting from 0.

findIndex :: (Char -> Bool) -> Stream Char -> Maybe Int Source

The findIndex function takes a predicate and a stream and returns the index of the first element in the stream satisfying the predicate.

countChar :: Char -> Stream Char -> Int Source

O(n) The count function returns the number of times the query element appears in the given stream.