adding utility type and converter for varargs

Author: bbarker

Foreign/Matlab/Array.hsc

@@ -128,7 +128,8 @@ foreign import ccall unsafe mxDestroyArray :: MXArrayPtr -> IO ()
 freeMXArray :: MXArray a -> MIO ()
 freeMXArray a = withMXArray a mxDestroyArray
 
--- |Create and populate an MXArray in one go.
+-- | Create and populate an MXArray in one go. Named without 'mx' due to possible
+-- | conformity to a typeclass function.
 fromListIO :: (Foldable t, MXArrayComponent a) => t a -> MIO (MXArray a)
 fromListIO xs = do
   arr <- createMXArray [length xs]
@@ -138,7 +139,8 @@ fromListIO xs = do
     xsList = toList xs
 
 -- | Like fromListIO but wraps elements in a cell. Most useful for converting a list of strings
--- | to a MATLAB cell array of strings.
+-- | to a MATLAB cell array of strings. Named in conjunction with `fromListIO`, which is used
+-- | as part of the implementation.
 cellFromListsIO :: (Traversable s, Foldable t, MXArrayComponent a) => s (t a) -> MIO (MXArray MCell)
 cellFromListsIO xss = do
   listOfStructArrays <- sequence $ fromListIO <$> xss

Foreign/Matlab/Engine/Wrappers.hs

@@ -11,11 +11,15 @@ module Foreign.Matlab.Engine.Wrappers (
 , getArrayFromByteStream
 , getByteStreamFromArray
 , MEither(..), isMLeft, isMRight
+, VarArgIn, mxVarArgs
 ) where
 
-import Foreign.Matlab
-import Foreign.Matlab.Engine
-import Path
+import qualified Data.Map.Strict as DM
+import           Foreign.Matlab
+import           Foreign.Matlab.Engine
+import           Path
+
+type VarArgIn = DM.Map String MAnyArray
 
 -- | We require an absolute path in this case
 addpath :: Engine -> Path Abs Dir -> IO ()
@@ -55,3 +59,10 @@ isMRight :: MEither -> IO Bool
 isMRight me = do
   sFields <- mStructFields $ unMXEither me
   pure $ "right" `elem` sFields
+
+-- | Utility function to create an eval-able list of arguments for a vararg map.
+mxVarArgs :: VarArgIn -> [EngineEvalArg MAny]
+mxVarArgs varargin = DM.toList varargin >>= kvToArg
+  where
+  kvToArg :: (String, MAnyArray) -> [EngineEvalArg MAny]
+  kvToArg kv = [EvalStr $ fst kv, EvalArray $ snd kv]

Foreign/Matlab/Types.hs

@@ -35,7 +35,7 @@ module Foreign.Matlab.Types (
 
     -- * Opaque types
     MXArray,
-    MAnyArray,
+    MAny, MAnyArray,
     MCell(MCell), mCell,
     MStruct,
     MFun

matlab.cabal

@@ -68,6 +68,7 @@ library
 
   if flag(engine)
     Exposed-modules:  Foreign.Matlab.Engine
+    Build-depends:    containers
     extra-libraries:  eng
 
 Source-repository head