-- |
-- Module      : Data.Text.Internal.Functions
-- Copyright   : 2010 Bryan O'Sullivan
--
-- License     : BSD-style
-- Maintainer  : bos@serpentine.com
-- Stability   : experimental
-- Portability : GHC
--
-- /Warning/: this is an internal module, and does not have a stable
-- API or name. Functions in this module may not check or enforce
-- preconditions expected by public modules. Use at your own risk!
--
-- Useful functions.

module Data.Text.Internal.Functions
    (
      intersperse
    ) where

-- | A lazier version of Data.List.intersperse.  The other version
-- causes space leaks!
intersperse :: a -> [a] -> [a]
intersperse :: a -> [a] -> [a]
intersperse a
_   []     = []
intersperse a
sep (a
x:[a]
xs) = a
x a -> [a] -> [a]
forall a. a -> [a] -> [a]
: [a] -> [a]
go [a]
xs
  where
    go :: [a] -> [a]
go []     = []
    go (a
y:[a]
ys) = a
sep a -> [a] -> [a]
forall a. a -> [a] -> [a]
: a
ya -> [a] -> [a]
forall a. a -> [a] -> [a]
: [a] -> [a]
go [a]
ys
{-# INLINE intersperse #-}