Foreign.hsc

{-# Language ForeignFunctionInterface #-}

module Text.Sundown.Markdown.Foreign
       ( Callbacks
       , Extensions (..)
       , c_sd_markdown_new
       , c_sd_markdown_render
       , c_sd_markdown_free
       ) where

import Foreign
import Foreign.C.String
import Foreign.C.Types
import Text.Sundown.Buffer.Foreign
import Text.Sundown.Flag

#include "markdown.h"

-- | A set of switches to enable or disable markdown features.
data Extensions = Extensions
  { extNoIntraEmphasis :: Bool
    -- ^ Turn off underscores insode a word does designating emphasis.
  , extTables :: Bool
  , extFencedCode :: Bool
    -- ^ Turns on a non-indentation form of code-blocks, by blocking off a
    --   regionwith ~ or \`.
  , extAutolink :: Bool
    -- ^ Turn things that look like URLs and email addresses into links
  , extStrikethrough :: Bool
    -- ^ Surround text with `~` to designate it as struck through
  , extSpaceHeaders :: Bool
  , extSuperscript :: Bool
  , extLaxSpacing :: Bool
    -- ^ Allow blocks inside of paragraphs, instead requireing tags to be on
    --   separate lines
  }

instance Flag Extensions where
  flagIndexes exts = [ (#{const MKDEXT_NO_INTRA_EMPHASIS}, extNoIntraEmphasis exts)
                     , (#{const MKDEXT_TABLES}, extTables exts)
                     , (#{const MKDEXT_FENCED_CODE}, extFencedCode exts)
                     , (#{const MKDEXT_AUTOLINK}, extAutolink exts)
                     , (#{const MKDEXT_STRIKETHROUGH}, extStrikethrough exts)
                     , (#{const MKDEXT_SPACE_HEADERS}, extSpaceHeaders exts)
                     , (#{const MKDEXT_SUPERSCRIPT}, extSuperscript exts)
                     , (#{const MKDEXT_LAX_SPACING}, extLaxSpacing exts)
                     ]


data Callbacks

instance Storable Callbacks where
  sizeOf _ = (#size struct sd_callbacks)
  alignment _ = alignment (undefined :: Ptr ())
  peek _ = error "Callbacks.peek is not implemented"
  poke _ _ = error "Callbacks.poke is not implemented"

data Markdown

instance Storable Markdown where
  sizeOf _ = error "Markdown.sizeOf is not implemented"
  alignment _ = alignment (undefined :: Ptr ())
  peek _ = error "Markdown.peek is not implemented"
  poke _ = error "Markdown.poke is not implemented"

c_sd_markdown_new :: Extensions -> CSize -> Ptr Callbacks -> Ptr () -> IO (Ptr Markdown)
c_sd_markdown_new extensions max_nesting callbacks opaque =
  c_sd_markdown_new' (toCUInt extensions) max_nesting callbacks opaque
foreign import ccall "markdown.h sd_markdown_new"
  c_sd_markdown_new' :: CUInt -> CSize -> Ptr Callbacks -> Ptr () -> IO (Ptr Markdown)

foreign import ccall "markdown.h sd_markdown_render"
  c_sd_markdown_render :: Ptr Buffer -> CString -> CSize -> Ptr Markdown -> IO ()

foreign import ccall "markdown.h sd_markdown_free"
  c_sd_markdown_free :: Ptr Markdown -> IO ()