Add some utils

package.yaml

@@ -37,6 +37,7 @@ dependencies:
   # other
 - stm
 - hslogger
+- megaparsec
 
 library:
   source-dirs: src

src/EuphApi/Utils.hs

@@ -0,0 +1,79 @@
+-- | Some useful functions for bots.
+
+module EuphApi.Utils (
+  -- * Nick manipulation
+    mention
+  , atMention
+  , mentionReduce
+  -- * Commands
+  , Command
+  , runCommands
+  , runCommandsFromMessage
+  -- ** Creating commands
+  , command
+  , specificCommand
+  , commandFromParser
+  ) where
+
+import           Control.Monad
+import           Data.Char
+import           Data.Maybe
+
+import qualified Data.Text       as T
+import qualified Text.Megaparsec as P
+
+import qualified EuphApi.Bot     as B
+import qualified EuphApi.Types   as E
+
+{-
+ - Nick manipulation
+ -}
+
+-- | Convert a nick to an @-mentionable version.
+-- Use this function when you want to @-mention somebody.
+--
+-- This removes spaces and some extra characters, while trying to stay close to
+-- the original nick.
+mention :: T.Text -> T.Text
+mention = T.filter (\c -> (not $ isSpace c) && (not $ c `elem` ".!?;&<'\""))
+
+-- | Same as 'atMention', but prepends an `@` character.
+atMention :: T.Text -> T.Text
+atMention = T.cons '@' . mention
+
+-- | Reduces a nick to a normal form such that all nicks that get @-mentioned
+-- by the same @-mention are reduced to the same normal form.
+--
+-- Use this function when you want to compare two nicks.
+mentionReduce :: T.Text -> T.Text
+mentionReduce = T.map toLower . mention
+
+{-
+ - Commands
+ -}
+
+-- | A simple function that is to be called with the content of received messages.
+--
+-- If you just want to add a simple command, see 'command' and 'specificCommand'.
+-- For more flexibility/more regex-like functionality, see 'commandFromParser'.
+type Command b c = T.Text -> B.Bot b c ()
+
+-- | Runs a list of commands.
+runCommands :: [Command b c] -> T.Text -> B.Bot b c ()
+-- runCommands cs t = void $ sequence $ map ($t) cs
+-- runCommands cs t = void . sequence $ cs <*> pure t
+runCommands cs = void . sequence . sequence cs
+
+-- | Runs a list of commands, using the content of a 'E.Message'.
+runCommandsFromMessage :: [Command b c] -> E.Message -> B.Bot b c ()
+runCommandsFromMessage cs = runCommands cs . E.msgContent
+
+-- | Creates a 'Command' from a parser and a bot action.
+commandFromParser :: (Ord e) => P.Parsec e T.Text a -> (a -> B.Bot b c ()) -> Command b c
+commandFromParser p f t = fromMaybe (return ()) $ f <$> P.parseMaybe p t
+
+command :: T.Text -> B.Bot b c () -> Command b c
+command = undefined
+
+specificCommand :: T.Text -> B.Bot b c () -> Command b c
+specificCommand = undefined