Subdivide Text.Pandoc.Class into small modules (#6106)

* Extract CommonState into submodule

* Extract PandocMonad into submodule

* PandocMonad: ensure all functions have Haddock documentation

1 files changed, 80 insertions, 0 deletions

diff --git a/src/Text/Pandoc/Class/CommonState.hs b/src/Text/Pandoc/Class/CommonState.hs
new file mode 100644
index 000000000..4a0f66859
--- /dev/null
+++ b/src/Text/Pandoc/Class/CommonState.hs
@@ -0,0 +1,80 @@
+{- |
+Module      : Text.Pandoc.Class.CommonState
+Copyright   : Copyright (C) 2016-2020 Jesse Rosenthal, John MacFarlane
+License     : GNU GPL, version 2 or above
+
+Maintainer  : Jesse Rosenthal <jrosenthal@jhu.edu>
+Stability   : alpha
+Portability : portable
+
+Common state shared by all pandoc-specific operations, including
+those in readers, writers, and Lua filters.
+-}
+
+module Text.Pandoc.Class.CommonState
+  ( CommonState(..)
+  , defaultCommonState
+  )
+where
+
+import Data.Default (Default (def))
+import Data.Text (Text)
+import Text.Pandoc.BCP47 (Lang)
+import Text.Pandoc.MediaBag (MediaBag)
+import Text.Pandoc.Logging (LogMessage, Verbosity (WARNING))
+import Text.Pandoc.Translations (Translations)
+
+-- | 'CommonState' represents state that is used by all
+-- instances of 'PandocMonad'.  Normally users should not
+-- need to interact with it directly; instead, auxiliary
+-- functions like 'setVerbosity' and 'withMediaBag' should be used.
+data CommonState = CommonState
+  { stLog          :: [LogMessage]
+    -- ^ A list of log messages in reverse order
+  , stUserDataDir  :: Maybe FilePath
+    -- ^ Directory to search for data files
+  , stSourceURL    :: Maybe Text
+    -- ^ Absolute URL + dir of 1st source file
+  , stRequestHeaders :: [(Text, Text)]
+    -- ^ Headers to add for HTTP requests
+  , stMediaBag     :: MediaBag
+    -- ^ Media parsed from binary containers
+  , stTranslations :: Maybe (Lang, Maybe Translations)
+    -- ^ Translations for localization
+  , stInputFiles   :: [FilePath]
+    -- ^ List of input files from command line
+  , stOutputFile   :: Maybe FilePath
+    -- ^ Output file from command line
+  , stResourcePath :: [FilePath]
+    -- ^ Path to search for resources like
+    -- included images
+  , stVerbosity    :: Verbosity
+    -- ^ Verbosity level
+  , stTrace        :: Bool
+    -- ^ Controls whether tracing messages are
+    -- issued.
+  }
+
+-- | The default @'CommonState'@. All fields are initialized as the
+-- monoid identity of their resprective type, except for:
+--
+--   * @'stResourcePath'@, which is set to @["."]@,
+--   * @'stTrace'@, which is set to @'False'@, and
+--   * @'stVerbosity'@, which is set to @WARNING@.
+defaultCommonState :: CommonState
+defaultCommonState = CommonState
+  { stLog = []
+  , stUserDataDir = Nothing
+  , stSourceURL = Nothing
+  , stRequestHeaders = []
+  , stMediaBag = mempty
+  , stTranslations = Nothing
+  , stInputFiles = []
+  , stOutputFile = Nothing
+  , stResourcePath = ["."]
+  , stVerbosity = WARNING
+  , stTrace = False
+  }
+
+instance Default CommonState where
+  def = defaultCommonState