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{-
Copyright © 2017 Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-}
{-# LANGUAGE OverloadedStrings #-}
{- |
Module : Text.Pandoc.Lua
Copyright : Copyright © 2017 Albert Krewinkel
License : GNU GPL, version 2 or above
Maintainer : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
Stability : alpha
Pandoc lua utils.
-}
module Text.Pandoc.Lua ( runLuaFilter ) where
import Control.Monad ( (>=>), when )
import Control.Monad.Trans ( MonadIO(..) )
import Data.HashMap.Lazy ( HashMap )
import Data.Text ( Text, pack, unpack )
import Data.Text.Encoding ( decodeUtf8 )
import Scripting.Lua ( LuaState, StackValue(..) )
import Scripting.Lua.Aeson ( newstate )
import Text.Pandoc.Definition ( Block(..), Inline(..), Pandoc(..) )
import Text.Pandoc.Lua.PandocModule
import Text.Pandoc.Lua.StackInstances ()
import Text.Pandoc.Walk
import qualified Data.HashMap.Lazy as HashMap
import qualified Scripting.Lua as Lua
runLuaFilter :: (MonadIO m)
=> FilePath -> [String] -> Pandoc -> m Pandoc
runLuaFilter filterPath args pd = liftIO $ do
lua <- newstate
Lua.openlibs lua
-- create table in registry to store filter functions
Lua.push lua ("PANDOC_FILTER_FUNCTIONS"::String)
Lua.newtable lua
Lua.rawset lua Lua.registryindex
-- store module in global "pandoc"
pushPandocModule lua
Lua.setglobal lua "pandoc"
status <- Lua.loadfile lua filterPath
if (status /= 0)
then do
luaErrMsg <- unpack . decodeUtf8 <$> Lua.tostring lua 1
error luaErrMsg
else do
Lua.call lua 0 1
Just luaFilters <- Lua.peek lua (-1)
Lua.push lua (map pack args)
Lua.setglobal lua "PandocParameters"
doc <- runAll luaFilters >=> luaFilter lua "filter_doc" $ pd
Lua.close lua
return doc
runAll :: [LuaFilter] -> Pandoc -> IO Pandoc
runAll [] = return
runAll (x:xs) = walkMWithLuaFilter x >=> runAll xs
luaFilter :: Lua.LuaState -> String -> Pandoc -> IO Pandoc
luaFilter lua luaFn x = do
fnExists <- isLuaFunction lua luaFn
if fnExists
then walkM (Lua.callfunc lua luaFn :: Pandoc -> IO Pandoc) x
else return x
walkMWithLuaFilter :: LuaFilter -> Pandoc -> IO Pandoc
walkMWithLuaFilter (LuaFilter lua inlineFnMap blockFnMap docFnMap) =
walkM (execInlineLuaFilter lua inlineFnMap) >=>
walkM (execBlockLuaFilter lua blockFnMap) >=>
walkM (execDocLuaFilter lua docFnMap)
type InlineFunctionMap = HashMap Text (LuaFilterFunction Inline)
type BlockFunctionMap = HashMap Text (LuaFilterFunction Block)
type DocFunctionMap = HashMap Text (LuaFilterFunction Pandoc)
data LuaFilter =
LuaFilter LuaState InlineFunctionMap BlockFunctionMap DocFunctionMap
newtype LuaFilterFunction a = LuaFilterFunction { functionIndex :: Int }
execDocLuaFilter :: LuaState
-> HashMap Text (LuaFilterFunction Pandoc)
-> Pandoc -> IO Pandoc
execDocLuaFilter lua fnMap x = do
let docFnName = "Doc"
case HashMap.lookup docFnName fnMap of
Nothing -> return x
Just fn -> runLuaFilterFunction lua fn x
execBlockLuaFilter :: LuaState
-> HashMap Text (LuaFilterFunction Block)
-> Block -> IO Block
execBlockLuaFilter lua fnMap x = do
let filterOrId constr = case HashMap.lookup constr fnMap of
Nothing -> return x
Just fn -> runLuaFilterFunction lua fn x
case x of
Plain _ -> filterOrId "Plain"
Para _ -> filterOrId "Para"
LineBlock _ -> filterOrId "LineBlock"
CodeBlock _ _ -> filterOrId "CodeBlock"
RawBlock _ _ -> filterOrId "RawBlock"
BlockQuote _ -> filterOrId "BlockQuote"
OrderedList _ _ -> filterOrId "OrderedList"
BulletList _ -> filterOrId "BulletList"
DefinitionList _ -> filterOrId "DefinitionList"
Header _ _ _ -> filterOrId "Header"
HorizontalRule -> filterOrId "HorizontalRule"
Table _ _ _ _ _ -> filterOrId "Table"
Div _ _ -> filterOrId "Div"
Null -> filterOrId "Null"
execInlineLuaFilter :: LuaState
-> HashMap Text (LuaFilterFunction Inline)
-> Inline -> IO Inline
execInlineLuaFilter lua fnMap x = do
let filterOrId constr = case HashMap.lookup constr fnMap of
Nothing -> return x
Just fn -> runLuaFilterFunction lua fn x
case x of
Cite _ _ -> filterOrId "Cite"
Code _ _ -> filterOrId "Code"
Emph _ -> filterOrId "Emph"
Image _ _ _ -> filterOrId "Image"
LineBreak -> filterOrId "LineBreak"
Link _ _ _ -> filterOrId "Link"
Math _ _ -> filterOrId "Math"
Note _ -> filterOrId "Note"
Quoted _ _ -> filterOrId "Quoted"
RawInline _ _ -> filterOrId "RawInline"
SmallCaps _ -> filterOrId "SmallCaps"
SoftBreak -> filterOrId "SoftBreak"
Space -> filterOrId "Space"
Span _ _ -> filterOrId "Span"
Str _ -> filterOrId "Str"
Strikeout _ -> filterOrId "Strikeout"
Strong _ -> filterOrId "Strong"
Subscript _ -> filterOrId "Subscript"
Superscript _ -> filterOrId "Superscript"
instance StackValue LuaFilter where
valuetype _ = Lua.TTABLE
push = undefined
peek lua i = do
-- TODO: find a more efficient way of doing this in a typesafe manner.
inlineFnMap <- Lua.peek lua i
blockFnMap <- Lua.peek lua i
docFnMap <- Lua.peek lua i
return $ LuaFilter lua <$> inlineFnMap <*> blockFnMap <*> docFnMap
runLuaFilterFunction :: (StackValue a)
=> LuaState -> LuaFilterFunction a -> a -> IO a
runLuaFilterFunction lua lf inline = do
pushFilterFunction lua lf
Lua.push lua inline
Lua.call lua 1 1
Just res <- Lua.peek lua (-1)
Lua.pop lua 1
return res
-- | Push the filter function to the top of the stack.
pushFilterFunction :: Lua.LuaState -> LuaFilterFunction a -> IO ()
pushFilterFunction lua lf = do
-- The function is stored in a lua registry table, retrieve it from there.
push lua ("PANDOC_FILTER_FUNCTIONS"::String)
Lua.rawget lua Lua.registryindex
Lua.rawgeti lua (-1) (functionIndex lf)
Lua.remove lua (-2) -- remove registry table from stack
instance StackValue (LuaFilterFunction a) where
valuetype _ = Lua.TFUNCTION
push lua v = pushFilterFunction lua v
peek lua i = do
isFn <- Lua.isfunction lua i
when (not isFn) (error $ "Not a function at index " ++ (show i))
Lua.pushvalue lua i
push lua ("PANDOC_FILTER_FUNCTIONS"::String)
Lua.rawget lua Lua.registryindex
len <- Lua.objlen lua (-1)
Lua.insert lua (-2)
Lua.rawseti lua (-2) (len + 1)
Lua.pop lua 1
return . Just $ LuaFilterFunction (len + 1)
isLuaFunction :: Lua.LuaState -> String -> IO Bool
isLuaFunction lua fnName = do
Lua.getglobal lua fnName
res <- Lua.isfunction lua (-1)
Lua.pop lua (-1)
return res
|
