Property.hs

-----------------------------------------------------------------------------
-- |
-- Module      :  Data.OrgMode.Parse.Attoparsec.Drawer.Property
-- Copyright   :  © 2014 Parnell Springmeyer
-- License     :  All Rights Reserved
-- Maintainer  :  Parnell Springmeyer <parnell@digitalmentat.com>
-- Stability   :  stable
--
-- Parsing combinators for org-mode section property drawers.
----------------------------------------------------------------------------

{-# LANGUAGE OverloadedStrings #-}

module Data.OrgMode.Parse.Attoparsec.Drawer.Property
( parseProperties
, property
, PropertyKey
, PropertyVal
)
where

import           Control.Applicative                          ((*>), (<*))
import           Data.Attoparsec.Text                         as T
import           Data.Attoparsec.Types                        as Attoparsec
import           Data.HashMap.Strict                          (fromList)
import           Data.Text                                    (Text)
import qualified Data.Text                                    as Text

import           Data.OrgMode.Parse.Attoparsec.Drawer.Generic as Drawer.Generic
import           Data.OrgMode.Types

type PropertyKey = Text
type PropertyVal = Text

-- | Parse a @PROPERTY@ drawer.
--
-- > :PROPERTIES:
-- > :DATE: [2014-12-14 11:00]
-- > :NOTE: Something really crazy happened today!
-- > :END:
parseProperties :: Attoparsec.Parser Text Properties
parseProperties = Properties . fromList <$> (drawerBegin *> manyTill property Drawer.Generic.drawerEnd)
  where
    drawerBegin = Drawer.Generic.parseDrawerDelim "PROPERTIES"

-- | Parse a property of a drawer.
--
-- Properties *must* be a `:KEY: value` pair, the key can be of any
-- case and contain any characters except for newlines and colons
-- (since they delimit the start and end of the key).
property :: Attoparsec.Parser Text (PropertyKey, PropertyVal)
property = (,) <$> parseKey <*> parseVal
  where
    parseKey  = skipSpace *> skip (== ':') *> takeWhile1 (/= ':') <* skip (== ':')
    parseVal  = Text.strip <$> (skipSpace *> takeValue)
    takeValue = takeWhile1 (not . isEndOfLine)