Lua: cleanup Lua utils, remove unused functions.

1 files changed, 28 insertions, 56 deletions

diff --git a/src/Text/Pandoc/Lua/Util.hs b/src/Text/Pandoc/Lua/Util.hs
index ea9ec2554..c12884a10 100644
--- a/src/Text/Pandoc/Lua/Util.hs
+++ b/src/Text/Pandoc/Lua/Util.hs
@@ -31,14 +31,11 @@ Lua utility functions.
 -}
 module Text.Pandoc.Lua.Util
   ( getTag
-  , getTable
-  , addValue
+  , rawField
+  , addField
   , addFunction
-  , getRawInt
-  , setRawInt
-  , addRawInt
+  , addValue
   , typeCheck
-  , raiseError
   , popValue
   , PushViaCall
   , pushViaCall
@@ -51,34 +48,30 @@ import Prelude
 import Control.Monad (when)
 import Control.Monad.Catch (finally)
 import Data.ByteString.Char8 (unpack)
-import Foreign.Lua (FromLuaStack (..), NumResults, Lua, NumArgs, StackIndex,
-                    ToLuaStack (..), ToHaskellFunction)
-import Foreign.Lua.Api (Status, call, pop, rawget, rawgeti, rawset, rawseti)
+import Foreign.Lua (FromLuaStack, Lua, NumArgs, StackIndex, Status,
+                    ToLuaStack, ToHaskellFunction)
 import Text.Pandoc.Class (readDataFile, runIOorExplode, setUserDataDir)
 
 import qualified Foreign.Lua as Lua
 
--- | Adjust the stack index, assuming that @n@ new elements have been pushed on
--- the stack.
-adjustIndexBy :: StackIndex -> StackIndex -> StackIndex
-adjustIndexBy idx n =
-  if idx < 0
-  then idx - n
-  else idx
-
 -- | Get value behind key from table at given index.
-getTable :: (ToLuaStack a, FromLuaStack b) => StackIndex -> a -> Lua b
-getTable idx key = do
-  push key
-  rawget (idx `adjustIndexBy` 1)
+rawField :: FromLuaStack a => StackIndex -> String -> Lua a
+rawField idx key = do
+  absidx <- Lua.absindex idx
+  Lua.push key
+  Lua.rawget absidx
   popValue
 
+-- | Add a value to the table at the top of the stack at a string-index.
+addField :: ToLuaStack a => String -> a -> Lua ()
+addField = addValue
+
 -- | Add a key-value pair to the table at the top of the stack.
 addValue :: (ToLuaStack a, ToLuaStack b) => a -> b -> Lua ()
 addValue key value = do
-  push key
-  push value
-  rawset (-3)
+  Lua.push key
+  Lua.push value
+  Lua.rawset (Lua.nthFromTop 3)
 
 -- | Add a function to the table at the top of the stack, using the given name.
 addFunction :: ToHaskellFunction a => String -> a -> Lua ()
@@ -88,22 +81,6 @@ addFunction name fn = do
   Lua.wrapHaskellFunction
   Lua.rawset (-3)
 
--- | Get value behind key from table at given index.
-getRawInt :: FromLuaStack a => StackIndex -> Int -> Lua a
-getRawInt idx key = do
-  rawgeti idx key
-  popValue
-
--- | Set numeric key/value in table at the given index
-setRawInt :: ToLuaStack a => StackIndex -> Int -> a -> Lua ()
-setRawInt idx key value = do
-  push value
-  rawseti (idx `adjustIndexBy` 1) key
-
--- | Set numeric key/value in table at the top of the stack.
-addRawInt :: ToLuaStack a => Int -> a -> Lua ()
-addRawInt = setRawInt (-1)
-
 typeCheck :: StackIndex -> Lua.Type -> Lua ()
 typeCheck idx expected = do
   actual <- Lua.ltype idx
@@ -112,16 +89,11 @@ typeCheck idx expected = do
     actName <- Lua.typename actual
     Lua.throwLuaError $ "expected " ++ expName ++ " but got " ++ actName ++ "."
 
-raiseError :: ToLuaStack a => a -> Lua NumResults
-raiseError e = do
-  Lua.push e
-  fromIntegral <$> Lua.lerror
-
 -- | Get, then pop the value at the top of the stack.
 popValue :: FromLuaStack a => Lua a
 popValue = do
   resOrError <- Lua.peekEither (-1)
-  pop 1
+  Lua.pop 1
   case resOrError of
     Left err -> Lua.throwLuaError err
     Right x -> return x
@@ -136,11 +108,11 @@ instance PushViaCall (Lua ()) where
     Lua.push fn
     Lua.rawget Lua.registryindex
     pushArgs
-    call num 1
+    Lua.call num 1
 
 instance (ToLuaStack a, PushViaCall b) => PushViaCall (a -> b) where
   pushViaCall' fn pushArgs num x =
-    pushViaCall' fn (pushArgs *> push x) (num + 1)
+    pushViaCall' fn (pushArgs *> Lua.push x) (num + 1)
 
 -- | Push an value to the stack via a lua function. The lua function is called
 -- with all arguments that are passed to this function and is expected to return
@@ -163,9 +135,9 @@ loadScriptFromDataDir datadir scriptFile = do
       "Couldn't load '" ++ scriptFile ++ "'.\n" ++ msg
 
 -- | Load a string and immediately perform a full garbage collection. This is
--- important to keep the program from hanging: If the program contained a call
--- to @require@, the a new loader function was created which then become
--- garbage. If that function is collected at an inopportune times, i.e. when the
+-- important to keep the program from hanging: If the program containes a call
+-- to @require@, then a new loader function is created which then becomes
+-- garbage. If that function is collected at an inopportune time, i.e. when the
 -- Lua API is called via a function that doesn't allow calling back into Haskell
 -- (getraw, setraw, …), then the function's finalizer, and the full program,
 -- will hang.
@@ -182,8 +154,8 @@ dostring' script = do
 -- metatable.
 getTag :: StackIndex -> Lua String
 getTag idx = do
-  top <- Lua.gettop
-  hasMT <- Lua.getmetatable idx
-  push "tag"
-  if hasMT then Lua.rawget (-2) else Lua.rawget (idx `adjustIndexBy` 1)
-  peek Lua.stackTop `finally` Lua.settop top
+  -- push metatable or just the table
+  Lua.getmetatable idx >>= \hasMT -> when (not hasMT) (Lua.pushvalue idx)
+  Lua.push "tag"
+  Lua.rawget (Lua.nthFromTop 2)
+  Lua.peek Lua.stackTop `finally` Lua.pop 2