4066a38 · typeable/pandoc

git.iko.soy/typeable/pandoc

Lua filters: use script to initialize the interpreter

The file `init.lua` is used to initialize the Lua interpreter which is used in Lua filters. This gives users the option to require libraries which they want to use in all of their filters, and to extend default modules.

commit4066a385ace1cee53336bf4c10734239044a92ae authorAlbert Krewinkel <albert@zeitkraut.de> dateWed 6 Dec 2017, 20:45 (9 years ago) parentd5b1c7b

5 files changed+46−14

compare with master

unifiedsplit

data/init.lua+6 doc/lua-filters.md+29−1 pandoc.cabal+2 src/Text/Pandoc/Lua.hs+5−10 src/Text/Pandoc/Lua/PandocModule.hs+4−3

data/init.luanew file+6

@@ -0,0 +1,6 @@

1+-- This Lua script is run every time the Lua interpreter is started when running

2+-- a Lua filter. It can be customized to load additional modules or to alter the

3+-- default modules.

5+pandoc = require 'pandoc'

6+pandoc.mediabag = require 'pandoc.mediabag'

doc/lua-filters.md+29−1

@@ -3,7 +3,7 @@ title: Pandoc Lua Filters

33author:

44- Albert Krewinkel

55- John MacFarlane

6−date: 'November 20, 2017'

6+date: 'December 6, 2017'

77---

99# Introduction

@@ -176,6 +176,34 @@ Some pandoc functions have been made available in lua:

176176 which stores binary content such as images that may be

177177 included in the final document.

178178

179+# Lua interpreter initialization

180+

181+The way the Lua interpreter is set-up can be controlled by

182+placing a file `init.lua` in pandoc's data directory. The

183+default init file loads the `pandoc` and `pandoc.mediabag`

184+modules:

185+

186+``` lua

187+pandoc = require 'pandoc'

188+pandoc.mediabag = require 'pandoc.mediabag'

189+```

190+

191+A common use-case would be to add code to load additional

192+modules or to alter default modules. E.g., the following snippet

193+adds all unicode-aware functions defined in the [`text`

194+module](#module-text) to the default `string` module, prefixed

195+with the string `uc_`.

196+

197+```lua

198+for name, fn in pairs(require 'text') do

199+ string['uc_' .. name] = fn

200+end

201+```

202+

203+This makes it possible to apply these functions on strings using

204+colon syntax (`mystring:uc_upper()`).

205+

206+

179207# Examples

180208

181209## Macro substitution.

pandoc.cabal+2

@@ -108,6 +108,8 @@ data-files:

108108 data/abbreviations

109109 -- sample lua custom writer

110110 data/sample.lua

111+ -- lua init script

112+ data/init.lua

111113 -- pandoc lua module

112114 data/pandoc.lua

113115 -- lua List module

src/Text/Pandoc/Lua.hs+5−10

@@ -48,10 +48,11 @@ import Foreign.Lua (FromLuaStack (peek), Lua, LuaException (..),

4848 Status (OK), ToLuaStack (push))

4949import Text.Pandoc.Class (PandocIO, getCommonState, getMediaBag, setMediaBag)

5050import Text.Pandoc.Definition

51+import Text.Pandoc.Lua.Filter (LuaFilter, walkMWithLuaFilter)

5152import Text.Pandoc.Lua.Packages (LuaPackageParams (..),

5253 installPandocPackageSearcher)

53−import Text.Pandoc.Lua.PandocModule (pushMediaBagModule, pushPandocModule)

54−import Text.Pandoc.Lua.Filter (LuaFilter, walkMWithLuaFilter)

54+import Text.Pandoc.Lua.PandocModule (pushPandocModule) -- TODO: remove

55+import Text.Pandoc.Lua.Util (loadScriptFromDataDir)

5556import qualified Foreign.Lua as Lua

5657import qualified Foreign.Lua.Module.Text as Lua

5758

@@ -101,17 +102,11 @@ luaPackageParams datadir = do

101102

102103-- Initialize the lua state with all required values

103104initLuaState :: LuaPackageParams -> Lua ()

104−initLuaState luaPkgParams@(LuaPackageParams commonState datadir mbRef) = do

105+initLuaState luaPkgParams = do

105106 Lua.openlibs

106107 Lua.preloadTextModule "text"

107108 installPandocPackageSearcher luaPkgParams

108− pushPandocModule datadir

109− -- add MediaBag module

110− push "mediabag"

111− pushMediaBagModule commonState mbRef

112− Lua.rawset (-3)

113− Lua.setglobal "pandoc"

114− return ()

109+ loadScriptFromDataDir (luaPkgDataDir luaPkgParams) "init.lua"

115110

116111pushGlobalFilter :: Lua ()

117112pushGlobalFilter = do

src/Text/Pandoc/Lua/PandocModule.hs+4−3

@@ -60,7 +60,7 @@ import qualified Text.Pandoc.MediaBag as MB

6060

6161-- | Push the "pandoc" on the lua stack. Requires the `list` module to be

6262-- loaded.

63−pushPandocModule :: Maybe FilePath -> Lua ()

63+pushPandocModule :: Maybe FilePath -> Lua NumResults

6464pushPandocModule datadir = do

6565 loadScriptFromDataDir datadir "pandoc.lua"

6666 addFunction "_pipe" pipeFn

@@ -68,6 +68,7 @@ pushPandocModule datadir = do

6868 addFunction "sha1" sha1HashFn

6969 addFunction "walk_block" walkBlock

7070 addFunction "walk_inline" walkInline

71+ return 1

7172

7273walkElement :: (ToLuaStack a, Walkable [Inline] a, Walkable [Block] a)

7374 => a -> LuaFilter -> Lua NumResults

@@ -99,14 +100,14 @@ readDoc formatSpec content = do

99100--

100101-- MediaBag submodule

101102--

102−pushMediaBagModule :: CommonState -> IORef MB.MediaBag -> Lua ()

103+pushMediaBagModule :: CommonState -> IORef MB.MediaBag -> Lua NumResults

103104pushMediaBagModule commonState mediaBagRef = do

104105 Lua.newtable

105106 addFunction "insert" (insertMediaFn mediaBagRef)

106107 addFunction "lookup" (lookupMediaFn mediaBagRef)

107108 addFunction "list" (mediaDirectoryFn mediaBagRef)

108109 addFunction "fetch" (fetch commonState mediaBagRef)

109− return ()

110+ return 1

110111

111112addFunction :: ToHaskellFunction a => String -> a -> Lua ()

112113addFunction name fn = do