{-# LANGUAGE OverloadedStrings #-} {- | Module : Text.Pandoc.Readers.Org.Shared Copyright : Copyright (C) 2014-2021 Albert Krewinkel License : GNU GPL, version 2 or above Maintainer : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de> Utility functions used in other Pandoc Org modules. -} module Text.Pandoc.Readers.Org.Shared ( cleanLinkText , isImageFilename , originalLang , translateLang , exportsCode ) where import Data.Char (isAlphaNum) import Data.Text (Text) import qualified Data.Text as T import System.FilePath (isValid, takeExtension) import Text.Pandoc.Shared (elemText) -- | Check whether the given string looks like the path to of URL of an image. isImageFilename :: Text -> Bool isImageFilename fp = hasImageExtension && (isValid (T.unpack fp) || isKnownProtocolUri) where hasImageExtension = takeExtension (T.unpack $ T.toLower fp) `elem` imageExtensions isKnownProtocolUri = any (\x -> (x <> "://") `T.isPrefixOf` fp) protocols imageExtensions = [ ".jpeg", ".jpg", ".png", ".gif", ".svg" ] protocols = [ "file", "http", "https" ] -- | Cleanup and canonicalize a string describing a link. Return @Nothing@ if -- the string does not appear to be a link. cleanLinkText :: Text -> Maybe Text cleanLinkText s | Just _ <- T.stripPrefix "/" s = Just $ "file://" <> s -- absolute path | Just _ <- T.stripPrefix "./" s = Just s -- relative path | Just _ <- T.stripPrefix "../" s = Just s -- relative path -- Relative path or URL (file schema) | Just s' <- T.stripPrefix "file:" s = Just $ if "//" `T.isPrefixOf` s' then s else s' | otherwise = if isUrl s then Just s else Nothing where isUrl :: Text -> Bool isUrl cs = let (scheme, path) = T.break (== ':') cs in T.all (\c -> isAlphaNum c || c `elemText` ".-") scheme && not (T.null path) -- | Creates an key-value pair marking the original language name specified for -- a piece of source code. -- | Creates an key-value attributes marking the original language name -- specified for a piece of source code. originalLang :: Text -> [(Text, Text)] originalLang lang = let transLang = translateLang lang in [("org-language", lang) | transLang /= lang] -- | Translate from Org-mode's programming language identifiers to those used -- by Pandoc. This is useful to allow for proper syntax highlighting in -- Pandoc output. translateLang :: Text -> Text translateLang cs = case cs of "C" -> "c" "C++" -> "cpp" "emacs-lisp" -> "commonlisp" -- emacs lisp is not supported "js" -> "javascript" "lisp" -> "commonlisp" "R" -> "r" "sh" -> "bash" "sqlite" -> "sql" _ -> cs exportsCode :: [(Text, Text)] -> Bool exportsCode = maybe True (`elem` ["code", "both"]) . lookup "exports"