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
210
211
212
213
214
215
216
217
218
219
220
221
|
{-
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 FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{- |
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, pushPandocModule ) where
import Control.Monad ( (>=>), when )
import Control.Monad.Trans ( MonadIO(..) )
import Data.Map ( Map )
import Scripting.Lua ( LuaState, StackValue(..) )
import Text.Pandoc.Definition
import Text.Pandoc.Lua.PandocModule ( pushPandocModule )
import Text.Pandoc.Lua.StackInstances ()
import Text.Pandoc.Walk
import qualified Data.Map as Map
import qualified Scripting.Lua as Lua
runLuaFilter :: (MonadIO m)
=> FilePath -> [String] -> Pandoc -> m Pandoc
runLuaFilter filterPath args pd = liftIO $ do
lua <- Lua.newstate
Lua.openlibs lua
-- create table in registry to store filter functions
Lua.push lua "PANDOC_FILTER_FUNCTIONS"
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
Just luaErrMsg <- Lua.peek lua 1
error luaErrMsg
else do
Lua.call lua 0 1
Just luaFilters <- Lua.peek lua (-1)
Lua.push lua args
Lua.setglobal lua "PandocParameters"
doc <- runAll luaFilters pd
Lua.close lua
return doc
runAll :: [LuaFilter] -> Pandoc -> IO Pandoc
runAll [] = return
runAll (x:xs) = walkMWithLuaFilter x >=> runAll xs
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 = Map String (LuaFilterFunction Inline)
type BlockFunctionMap = Map String (LuaFilterFunction Block)
type DocFunctionMap = Map String (LuaFilterFunction Pandoc)
data LuaFilter =
LuaFilter LuaState InlineFunctionMap BlockFunctionMap DocFunctionMap
newtype LuaFilterFunction a = LuaFilterFunction { functionIndex :: Int }
execDocLuaFilter :: LuaState
-> Map String (LuaFilterFunction Pandoc)
-> Pandoc -> IO Pandoc
execDocLuaFilter lua fnMap x = do
let docFnName = "Doc"
case Map.lookup docFnName fnMap of
Nothing -> return x
Just fn -> runLuaFilterFunction lua fn x
execBlockLuaFilter :: LuaState
-> Map String (LuaFilterFunction Block)
-> Block -> IO Block
execBlockLuaFilter lua fnMap x = do
let tryFilter :: String -> IO Block
tryFilter filterFnName =
case Map.lookup filterFnName fnMap of
Nothing -> return x
Just fn -> runLuaFilterFunction lua fn x
case x of
BlockQuote _ -> tryFilter "BlockQuote"
BulletList _ -> tryFilter "BulletList"
CodeBlock _ _ -> tryFilter "CodeBlock"
DefinitionList _ -> tryFilter "DefinitionList"
Div _ _ -> tryFilter "Div"
Header _ _ _ -> tryFilter "Header"
HorizontalRule -> tryFilter "HorizontalRule"
LineBlock _ -> tryFilter "LineBlock"
Null -> tryFilter "Null"
Para _ -> tryFilter "Para"
Plain _ -> tryFilter "Plain"
RawBlock _ _ -> tryFilter "RawBlock"
OrderedList _ _ -> tryFilter "OrderedList"
Table _ _ _ _ _ -> tryFilter "Table"
execInlineLuaFilter :: LuaState
-> Map String (LuaFilterFunction Inline)
-> Inline -> IO Inline
execInlineLuaFilter lua fnMap x = do
let tryFilter :: String -> IO Inline
tryFilter filterFnName =
case Map.lookup filterFnName fnMap of
Nothing -> return x
Just fn -> runLuaFilterFunction lua fn x
let tryFilterAlternatives :: [String] -> IO Inline
tryFilterAlternatives [] = return x
tryFilterAlternatives (fnName : alternatives) =
case Map.lookup fnName fnMap of
Nothing -> tryFilterAlternatives alternatives
Just fn -> runLuaFilterFunction lua fn x
case x of
Cite _ _ -> tryFilter "Cite"
Code _ _ -> tryFilter "Code"
Emph _ -> tryFilter "Emph"
Image _ _ _ -> tryFilter "Image"
LineBreak -> tryFilter "LineBreak"
Link _ _ _ -> tryFilter "Link"
Math DisplayMath _ -> tryFilterAlternatives ["DisplayMath", "Math"]
Math InlineMath _ -> tryFilterAlternatives ["InlineMath", "Math"]
Note _ -> tryFilter "Note"
Quoted DoubleQuote _ -> tryFilterAlternatives ["DoubleQuoted", "Quoted"]
Quoted SingleQuote _ -> tryFilterAlternatives ["SingleQuoted", "Quoted"]
RawInline _ _ -> tryFilter "RawInline"
SmallCaps _ -> tryFilter "SmallCaps"
SoftBreak -> tryFilter "SoftBreak"
Space -> tryFilter "Space"
Span _ _ -> tryFilter "Span"
Str _ -> tryFilter "Str"
Strikeout _ -> tryFilter "Strikeout"
Strong _ -> tryFilter "Strong"
Subscript _ -> tryFilter "Subscript"
Superscript _ -> tryFilter "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
-- | Helper class for pushing a single value to the stack via a lua function.
-- See @pushViaCall@.
class PushViaFilterFunction a b where
pushViaFilterFunction' :: LuaState -> LuaFilterFunction a -> IO () -> Int -> b
instance (StackValue a) => PushViaFilterFunction a (IO a) where
pushViaFilterFunction' lua lf pushArgs num = do
pushFilterFunction lua lf
pushArgs
Lua.call lua num 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
instance (PushViaFilterFunction a c, StackValue b) =>
PushViaFilterFunction a (b -> c) where
pushViaFilterFunction' lua lf pushArgs num x =
pushViaFilterFunction' lua lf (pushArgs *> push lua x) (num + 1)
-- | Push an value to the stack via a lua filter function. The function is
-- called with all arguments that are passed to this function and is expected to
-- return a single value.
runLuaFilterFunction :: (StackValue a, PushViaFilterFunction a b)
=> LuaState -> LuaFilterFunction a -> b
runLuaFilterFunction lua lf = pushViaFilterFunction' lua lf (return ()) 0
-- | 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)
|
