1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
{-
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
mbres <- Lua.peek lua (-1)
case mbres of
Nothing -> error $ "Error while trying to get a filter's return "
++ "value from lua stack."
Just res -> res <$ Lua.pop lua 1
-- | 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
|
