Lua: generate constants in module pandoc programmatically

data/pandoc.lua

@@ -372,86 +372,6 @@ M.SimpleTable = function(caption, aligns, widths, headers, rows)
   }
 end
 
-
-------------------------------------------------------------------------
--- Constants
--- @section constants
-
---- Author name is mentioned in the text.
--- @see Citation
--- @see Cite
-M.AuthorInText = "AuthorInText"
-
---- Author name is suppressed.
--- @see Citation
--- @see Cite
-M.SuppressAuthor = "SuppressAuthor"
-
---- Default citation style is used.
--- @see Citation
--- @see Cite
-M.NormalCitation = "NormalCitation"
-
---- Table cells aligned left.
--- @see Table
-M.AlignLeft = "AlignLeft"
-
---- Table cells right-aligned.
--- @see Table
-M.AlignRight = "AlignRight"
-
---- Table cell content is centered.
--- @see Table
-M.AlignCenter = "AlignCenter"
-
---- Table cells are alignment is unaltered.
--- @see Table
-M.AlignDefault = "AlignDefault"
-
---- Default list number delimiters are used.
--- @see OrderedList
-M.DefaultDelim = "DefaultDelim"
-
---- List numbers are delimited by a period.
--- @see OrderedList
-M.Period = "Period"
-
---- List numbers are delimited by a single parenthesis.
--- @see OrderedList
-M.OneParen = "OneParen"
-
---- List numbers are delimited by a double parentheses.
--- @see OrderedList
-M.TwoParens = "TwoParens"
-
---- List are numbered in the default style
--- @see OrderedList
-M.DefaultStyle = "DefaultStyle"
-
---- List items are numbered as examples.
--- @see OrderedList
-M.Example = "Example"
-
---- List are numbered using decimal integers.
--- @see OrderedList
-M.Decimal = "Decimal"
-
---- List are numbered using lower-case roman numerals.
--- @see OrderedList
-M.LowerRoman = "LowerRoman"
-
---- List are numbered using upper-case roman numerals
--- @see OrderedList
-M.UpperRoman = "UpperRoman"
-
---- List are numbered using lower-case alphabetic characters.
--- @see OrderedList
-M.LowerAlpha = "LowerAlpha"
-
---- List are numbered using upper-case alphabetic characters.
--- @see OrderedList
-M.UpperAlpha = "UpperAlpha"
-
 ------------------------------------------------------------------------
 -- Functions which have moved to different modules
 M.sha1 = utils.sha1

src/Text/Pandoc/Lua/Module/Pandoc.hs

@@ -1,5 +1,6 @@
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications  #-}
 {- |
    Module      : Text.Pandoc.Lua.Module.Pandoc
@@ -20,8 +21,10 @@ import Control.Applicative ((<|>), optional)
 import Control.Monad ((>=>), (<$!>), forM_, when)
 import Control.Monad.Catch (catch, throwM)
 import Control.Monad.Except (throwError)
+import Data.Data (Data, dataTypeConstrs, dataTypeOf, showConstr)
 import Data.Default (Default (..))
 import Data.Maybe (fromMaybe)
+import Data.Proxy (Proxy (Proxy))
 import Data.Text (Text)
 import HsLua as Lua hiding (Div, pushModule)
 import HsLua.Class.Peekable (PeekError)
@@ -87,6 +90,9 @@ pushModule = do
           pop 1 -- remaining constructor table
     addConstructorTable (blockConstructors @PandocError)
     addConstructorTable (inlineConstructors @PandocError)
+    -- Add string constants
+    forM_ stringConstants $ \c -> do
+      pushString c *> pushString c *> rawset (nth 3)
   return 1
 
 inlineConstructors :: LuaError e =>  [DocumentedFunction e]
@@ -307,6 +313,17 @@ otherConstructors =
   , mkListAttributes
   ]
 
+stringConstants :: [String]
+stringConstants =
+  let constrs :: forall a. Data a => Proxy a -> [String]
+      constrs _ = map showConstr . dataTypeConstrs . dataTypeOf @a $ undefined
+  in    constrs (Proxy @ListNumberStyle)
+     ++ constrs (Proxy @ListNumberDelim)
+     ++ constrs (Proxy @QuoteType)
+     ++ constrs (Proxy @MathType)
+     ++ constrs (Proxy @Alignment)
+     ++ constrs (Proxy @CitationMode)
+
 walkElement :: (Walkable (SingletonsList Inline) a,
                 Walkable (SingletonsList Block) a,
                 Walkable (List Inline) a,