{-# LANGUAGE CPP                 #-}
{-# LANGUAGE ForeignFunctionInterface #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeApplications    #-}
{-|
Module      : HsLua.ObjectOrientation
Copyright   : © 2021-2022 Albert Krewinkel
License     : MIT
Maintainer  : Albert Krewinkel <tarleb+hslua@zeitkraut.de>

This module provides types and functions to use Haskell values as
userdata objects in Lua. These objects wrap a Haskell value and provide
methods and properties to interact with the Haskell value.

The terminology in this module refers to the userdata values as /UD
objects/, and to their type as /UD type/.
-}
module HsLua.ObjectOrientation
  ( UDType
  , UDTypeWithList (..)
  , deftypeGeneric
  , deftypeGeneric'
  , methodGeneric
  , property
  , possibleProperty
  , readonly
  , alias
  , peekUD
  , pushUD
    -- * Helper types for building
  , Member
  , Property
  , Operation (..)
  , ListSpec
  , Possible (..)
  , Alias
  , AliasIndex (..)
  ) where

import Control.Monad ((<$!>), forM_, void, when)
import Data.Maybe (mapMaybe)
import Data.Map (Map)
#if !MIN_VERSION_base(4,12,0)
import Data.Semigroup (Semigroup ((<>)))
#endif
import Data.String (IsString (..))
import Data.Text (Text)
import Data.Void (Void)
import Foreign.Ptr (FunPtr)
import HsLua.Core as Lua
import HsLua.Marshalling
import HsLua.ObjectOrientation.Operation
import qualified Data.Map.Strict as Map
import qualified HsLua.Core.Unsafe as Unsafe
import qualified HsLua.Core.Utf8 as Utf8

-- | A userdata type, capturing the behavior of Lua objects that wrap
-- Haskell values. The type name must be unique; once the type has been
-- used to push or retrieve a value, the behavior can no longer be
-- modified through this type.
--
-- This type includes methods to define how the object should behave as
-- a read-only list of type @itemtype@.
data UDTypeWithList e fn a itemtype = UDTypeWithList
  { forall e fn a itemtype. UDTypeWithList e fn a itemtype -> Name
udName          :: Name
  , forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> [(Operation, fn)]
udOperations    :: [(Operation, fn)]
  , forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name (Property e a)
udProperties    :: Map Name (Property e a)
  , forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name fn
udMethods       :: Map Name fn
  , forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map AliasIndex Alias
udAliases       :: Map AliasIndex Alias
  , forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Maybe (ListSpec e a itemtype)
udListSpec      :: Maybe (ListSpec e a itemtype)
  , forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> fn -> LuaE e ()
udFnPusher      :: fn -> LuaE e ()
  }

-- | Pair of pairs, describing how a type can be used as a Lua list. The
-- first pair describes how to push the list items, and how the list is
-- extracted from the type; the second pair contains a method to
-- retrieve list items, and defines how the list is used to create an
-- updated value.
type ListSpec e a itemtype =
  ( (Pusher e itemtype, a -> [itemtype])
  , (Peeker e itemtype, a -> [itemtype] -> a)
  )

-- | A userdata type, capturing the behavior of Lua objects that wrap
-- Haskell values. The type name must be unique; once the type has been
-- used to push or retrieve a value, the behavior can no longer be
-- modified through this type.
type UDType e fn a = UDTypeWithList e fn a Void

-- | Defines a new type, defining the behavior of objects in Lua.
-- Note that the type name must be unique.
deftypeGeneric :: Pusher e fn           -- ^ function pusher
               -> Name                  -- ^ type name
               -> [(Operation, fn)]     -- ^ operations
               -> [Member e fn a]       -- ^ methods
               -> UDType e fn a
deftypeGeneric :: forall e fn a.
Pusher e fn
-> Name -> [(Operation, fn)] -> [Member e fn a] -> UDType e fn a
deftypeGeneric Pusher e fn
pushFunction Name
name [(Operation, fn)]
ops [Member e fn a]
members =
  forall e fn a itemtype.
Pusher e fn
-> Name
-> [(Operation, fn)]
-> [Member e fn a]
-> Maybe (ListSpec e a itemtype)
-> UDTypeWithList e fn a itemtype
deftypeGeneric' Pusher e fn
pushFunction Name
name [(Operation, fn)]
ops [Member e fn a]
members forall a. Maybe a
Nothing

-- | Defines a new type that could also be treated as a list; defines
-- the behavior of objects in Lua. Note that the type name must be
-- unique.
deftypeGeneric' :: Pusher e fn          -- ^ function pusher
                -> Name                 -- ^ type name
                -> [(Operation, fn)]    -- ^ operations
                -> [Member e fn a]      -- ^ methods
                -> Maybe (ListSpec e a itemtype)  -- ^ list access
                -> UDTypeWithList e fn a itemtype
deftypeGeneric' :: forall e fn a itemtype.
Pusher e fn
-> Name
-> [(Operation, fn)]
-> [Member e fn a]
-> Maybe (ListSpec e a itemtype)
-> UDTypeWithList e fn a itemtype
deftypeGeneric' Pusher e fn
pushFunction Name
name [(Operation, fn)]
ops [Member e fn a]
members Maybe (ListSpec e a itemtype)
mbListSpec = UDTypeWithList
  { udName :: Name
udName          = Name
name
  , udOperations :: [(Operation, fn)]
udOperations    = [(Operation, fn)]
ops
  , udProperties :: Map Name (Property e a)
udProperties    = forall k a. Ord k => [(k, a)] -> Map k a
Map.fromList forall a b. (a -> b) -> a -> b
$ forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe forall {e} {fn} {a}. Member e fn a -> Maybe (Name, Property e a)
mbproperties [Member e fn a]
members
  , udMethods :: Map Name fn
udMethods       = forall k a. Ord k => [(k, a)] -> Map k a
Map.fromList forall a b. (a -> b) -> a -> b
$ forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe forall {e} {b} {a}. Member e b a -> Maybe (Name, b)
mbmethods [Member e fn a]
members
  , udAliases :: Map AliasIndex Alias
udAliases       = forall k a. Ord k => [(k, a)] -> Map k a
Map.fromList forall a b. (a -> b) -> a -> b
$ forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe forall {e} {fn} {a}. Member e fn a -> Maybe (AliasIndex, Alias)
mbaliases [Member e fn a]
members
  , udListSpec :: Maybe (ListSpec e a itemtype)
udListSpec      = Maybe (ListSpec e a itemtype)
mbListSpec
  , udFnPusher :: Pusher e fn
udFnPusher      = Pusher e fn
pushFunction
  }
  where
    mbproperties :: Member e fn a -> Maybe (Name, Property e a)
mbproperties = \case
      MemberProperty Name
n Property e a
p -> forall a. a -> Maybe a
Just (Name
n, Property e a
p)
      Member e fn a
_ -> forall a. Maybe a
Nothing
    mbmethods :: Member e b a -> Maybe (Name, b)
mbmethods = \case
      MemberMethod Name
n b
m -> forall a. a -> Maybe a
Just (Name
n, b
m)
      Member e b a
_ -> forall a. Maybe a
Nothing
    mbaliases :: Member e fn a -> Maybe (AliasIndex, Alias)
mbaliases = \case
      MemberAlias AliasIndex
n Alias
a -> forall a. a -> Maybe a
Just (AliasIndex
n, Alias
a)
      Member e fn a
_ -> forall a. Maybe a
Nothing

-- | A read- and writable property on a UD object.
data Property e a = Property
  { forall e a. Property e a -> a -> LuaE e NumResults
propertyGet :: a -> LuaE e NumResults
  , forall e a. Property e a -> Maybe (StackIndex -> a -> LuaE e a)
propertySet :: Maybe (StackIndex -> a -> LuaE e a)
  , forall e a. Property e a -> Text
propertyDescription :: Text
  }

-- | Alias for a different property of this or of a nested object.
type Alias = [AliasIndex]

-- | Index types allowed in aliases (strings and integers)
data AliasIndex
  = StringIndex Name
  | IntegerIndex Lua.Integer
  deriving (AliasIndex -> AliasIndex -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: AliasIndex -> AliasIndex -> Bool
$c/= :: AliasIndex -> AliasIndex -> Bool
== :: AliasIndex -> AliasIndex -> Bool
$c== :: AliasIndex -> AliasIndex -> Bool
Eq, Eq AliasIndex
AliasIndex -> AliasIndex -> Bool
AliasIndex -> AliasIndex -> Ordering
AliasIndex -> AliasIndex -> AliasIndex
forall a.
Eq a
-> (a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
min :: AliasIndex -> AliasIndex -> AliasIndex
$cmin :: AliasIndex -> AliasIndex -> AliasIndex
max :: AliasIndex -> AliasIndex -> AliasIndex
$cmax :: AliasIndex -> AliasIndex -> AliasIndex
>= :: AliasIndex -> AliasIndex -> Bool
$c>= :: AliasIndex -> AliasIndex -> Bool
> :: AliasIndex -> AliasIndex -> Bool
$c> :: AliasIndex -> AliasIndex -> Bool
<= :: AliasIndex -> AliasIndex -> Bool
$c<= :: AliasIndex -> AliasIndex -> Bool
< :: AliasIndex -> AliasIndex -> Bool
$c< :: AliasIndex -> AliasIndex -> Bool
compare :: AliasIndex -> AliasIndex -> Ordering
$ccompare :: AliasIndex -> AliasIndex -> Ordering
Ord)

instance IsString AliasIndex where
  fromString :: String -> AliasIndex
fromString = Name -> AliasIndex
StringIndex forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. IsString a => String -> a
fromString

-- | A type member, either a method or a variable.
data Member e fn a
  = MemberProperty Name (Property e a)
  | MemberMethod Name fn
  | MemberAlias AliasIndex Alias

-- | Use a documented function as an object method.
methodGeneric :: Name -> fn -> Member e fn a
methodGeneric :: forall fn e a. Name -> fn -> Member e fn a
methodGeneric = forall e fn a. Name -> fn -> Member e fn a
MemberMethod

-- | A property or method which may be available in some instances but
-- not in others.
data Possible a
  = Actual a
  | Absent

-- | Declares a new read- and writable property.
property :: LuaError e
         => Name                       -- ^ property name
         -> Text                       -- ^ property description
         -> (Pusher e b, a -> b)       -- ^ how to get the property value
         -> (Peeker e b, a -> b -> a)  -- ^ how to set a new property value
         -> Member e fn a
property :: forall e b a fn.
LuaError e =>
Name
-> Text
-> (Pusher e b, a -> b)
-> (Peeker e b, a -> b -> a)
-> Member e fn a
property Name
name Text
desc (Pusher e b
push, a -> b
get) (Peeker e b
peek, a -> b -> a
set) =
  forall e b a fn.
LuaError e =>
Name
-> Text
-> (Pusher e b, a -> Possible b)
-> (Peeker e b, a -> b -> Possible a)
-> Member e fn a
possibleProperty Name
name Text
desc
    (Pusher e b
push, forall a. a -> Possible a
Actual forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> b
get)
    (Peeker e b
peek, \a
a b
b -> forall a. a -> Possible a
Actual (a -> b -> a
set a
a b
b))

-- | Declares a new read- and writable property which is not always
-- available.
possibleProperty :: LuaError e
  => Name                               -- ^ property name
  -> Text                               -- ^ property description
  -> (Pusher e b, a -> Possible b)      -- ^ how to get the property value
  -> (Peeker e b, a -> b -> Possible a) -- ^ how to set a new property value
  -> Member e fn a
possibleProperty :: forall e b a fn.
LuaError e =>
Name
-> Text
-> (Pusher e b, a -> Possible b)
-> (Peeker e b, a -> b -> Possible a)
-> Member e fn a
possibleProperty Name
name Text
desc (Pusher e b
push, a -> Possible b
get) (Peeker e b
peek, a -> b -> Possible a
set) = forall e fn a. Name -> Property e a -> Member e fn a
MemberProperty Name
name forall a b. (a -> b) -> a -> b
$
  Property
  { propertyGet :: a -> LuaE e NumResults
propertyGet = \a
x -> do
      case a -> Possible b
get a
x of
        Actual b
y -> CInt -> NumResults
NumResults CInt
1 forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ Pusher e b
push b
y
        Possible b
Absent   -> forall (m :: * -> *) a. Monad m => a -> m a
return (CInt -> NumResults
NumResults CInt
0)
  , propertySet :: Maybe (StackIndex -> a -> LuaE e a)
propertySet = forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$ \StackIndex
idx a
x -> do
      b
value  <- forall e a. LuaError e => Peek e a -> LuaE e a
forcePeek forall a b. (a -> b) -> a -> b
$ Peeker e b
peek StackIndex
idx
      case a -> b -> Possible a
set a
x b
value of
        Actual a
y -> forall (m :: * -> *) a. Monad m => a -> m a
return a
y
        Possible a
Absent   -> forall e a. LuaError e => String -> LuaE e a
failLua forall a b. (a -> b) -> a -> b
$ String
"Trying to set unavailable property "
                            forall a. Semigroup a => a -> a -> a
<> ByteString -> String
Utf8.toString (Name -> ByteString
fromName Name
name)
                            forall a. Semigroup a => a -> a -> a
<> String
"."
  , propertyDescription :: Text
propertyDescription = Text
desc
  }

-- | Creates a read-only object property. Attempts to set the value will
-- cause an error.
readonly :: Name                 -- ^ property name
         -> Text                 -- ^ property description
         -> (Pusher e b, a -> b) -- ^ how to get the property value
         -> Member e fn a
readonly :: forall e b a fn.
Name -> Text -> (Pusher e b, a -> b) -> Member e fn a
readonly Name
name Text
desc (Pusher e b
push, a -> b
get) = forall e fn a. Name -> Property e a -> Member e fn a
MemberProperty Name
name forall a b. (a -> b) -> a -> b
$
  Property
  { propertyGet :: a -> LuaE e NumResults
propertyGet = \a
x -> do
      Pusher e b
push forall a b. (a -> b) -> a -> b
$ a -> b
get a
x
      forall (m :: * -> *) a. Monad m => a -> m a
return (CInt -> NumResults
NumResults CInt
1)
  , propertySet :: Maybe (StackIndex -> a -> LuaE e a)
propertySet = forall a. Maybe a
Nothing
  , propertyDescription :: Text
propertyDescription = Text
desc
  }

-- | Define an alias for another, possibly nested, property.
alias :: AliasIndex    -- ^ property alias
      -> Text          -- ^ description
      -> [AliasIndex]  -- ^ sequence of nested properties
      -> Member e fn a
alias :: forall e fn a. AliasIndex -> Text -> Alias -> Member e fn a
alias AliasIndex
name Text
_desc = forall e fn a. AliasIndex -> Alias -> Member e fn a
MemberAlias AliasIndex
name

-- | Pushes the metatable for the given type to the Lua stack. Creates
-- the new table afresh on the first time it is needed, and retrieves it
-- from the registry after that.
pushUDMetatable :: LuaError e => UDTypeWithList e fn a itemtype -> LuaE e ()
pushUDMetatable :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushUDMetatable UDTypeWithList e fn a itemtype
ty = do
  Bool
created <- forall e. Name -> LuaE e Bool
newudmetatable (forall e fn a itemtype. UDTypeWithList e fn a itemtype -> Name
udName UDTypeWithList e fn a itemtype
ty)
  forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when Bool
created forall a b. (a -> b) -> a -> b
$ do
    forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add (Operation -> Name
metamethodName Operation
Index)    forall a b. (a -> b) -> a -> b
$ forall e. CFunction -> LuaE e ()
pushcfunction CFunction
hslua_udindex_ptr
    forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add (Operation -> Name
metamethodName Operation
Newindex) forall a b. (a -> b) -> a -> b
$ forall e. CFunction -> LuaE e ()
pushcfunction CFunction
hslua_udnewindex_ptr
    forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add (Operation -> Name
metamethodName Operation
Pairs)    forall a b. (a -> b) -> a -> b
$ forall e. LuaError e => HaskellFunction e -> LuaE e ()
pushHaskellFunction (forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e NumResults
pairsFunction UDTypeWithList e fn a itemtype
ty)
    forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
t a -> (a -> m b) -> m ()
forM_ (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> [(Operation, fn)]
udOperations UDTypeWithList e fn a itemtype
ty) forall a b. (a -> b) -> a -> b
$ \(Operation
op, fn
f) -> do
      forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add (Operation -> Name
metamethodName Operation
op) forall a b. (a -> b) -> a -> b
$ forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> fn -> LuaE e ()
udFnPusher UDTypeWithList e fn a itemtype
ty fn
f
    forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add Name
"getters" forall a b. (a -> b) -> a -> b
$ forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushGetters UDTypeWithList e fn a itemtype
ty
    forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add Name
"setters" forall a b. (a -> b) -> a -> b
$ forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushSetters UDTypeWithList e fn a itemtype
ty
    forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add Name
"methods" forall a b. (a -> b) -> a -> b
$ forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushMethods UDTypeWithList e fn a itemtype
ty
    forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add Name
"aliases" forall a b. (a -> b) -> a -> b
$ forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushAliases UDTypeWithList e fn a itemtype
ty
    case forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Maybe (ListSpec e a itemtype)
udListSpec UDTypeWithList e fn a itemtype
ty of
      Maybe (ListSpec e a itemtype)
Nothing -> forall (f :: * -> *) a. Applicative f => a -> f a
pure ()
      Just ((Pusher e itemtype
pushItem, a -> [itemtype]
_), (Peeker e itemtype, a -> [itemtype] -> a)
_) -> do
        forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add Name
"lazylisteval" forall a b. (a -> b) -> a -> b
$ forall e. LuaError e => HaskellFunction e -> LuaE e ()
pushHaskellFunction (forall itemtype e.
LuaError e =>
Pusher e itemtype -> LuaE e NumResults
lazylisteval Pusher e itemtype
pushItem)
  where
    add :: LuaError e => Name -> LuaE e () -> LuaE e ()
    add :: forall e. LuaError e => Name -> LuaE e () -> LuaE e ()
add Name
name LuaE e ()
op = do
      forall e. Name -> LuaE e ()
pushName Name
name
      LuaE e ()
op
      forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nth CInt
3)

-- | Retrieves a key from a Haskell-data holding userdata value.
--
-- Does the following, in order, and returns the first non-nil result:
--
--   - Checks the userdata's uservalue table for the given key;
--
--   - Looks up a @getter@ for the key and calls it with the userdata
--     and key as arguments;
--
--   - Looks up the key in the table in the @methods@ metafield.
foreign import ccall "hslobj.c &hslua_udindex"
  hslua_udindex_ptr :: FunPtr (State -> IO NumResults)

-- | Sets a new value in the userdata caching table via a setter
-- functions.
--
-- The actual assignment is performed by a setter function stored in the
-- @setter@ metafield. Throws an error if no setter function can be
-- found.
foreign import ccall "hslobj.c &hslua_udnewindex"
  hslua_udnewindex_ptr :: FunPtr (State -> IO NumResults)

-- | Sets a value in the userdata's caching table (uservalue). Takes the
-- same arguments as a @__newindex@ function.
foreign import ccall "hslobj.c &hslua_udsetter"
  hslua_udsetter_ptr :: FunPtr (State -> IO NumResults)

-- | Throws an error nothing that the given key is read-only.
foreign import ccall "hslobj.c &hslua_udreadonly"
  hslua_udreadonly_ptr :: FunPtr (State -> IO NumResults)

-- | Pushes the metatable's @getters@ field table.
pushGetters :: LuaError e => UDTypeWithList e fn a itemtype -> LuaE e ()
pushGetters :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushGetters UDTypeWithList e fn a itemtype
ty = do
  forall e. LuaE e ()
newtable
  forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ forall a b c. (a -> b -> c) -> b -> a -> c
flip forall (t :: * -> *) k a b.
Applicative t =>
(k -> a -> t b) -> Map k a -> t (Map k b)
Map.traverseWithKey (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name (Property e a)
udProperties UDTypeWithList e fn a itemtype
ty) forall a b. (a -> b) -> a -> b
$ \Name
name Property e a
prop -> do
    forall e. Name -> LuaE e ()
pushName Name
name
    forall e. LuaError e => HaskellFunction e -> LuaE e ()
pushHaskellFunction forall a b. (a -> b) -> a -> b
$ forall e a. LuaError e => Peek e a -> LuaE e a
forcePeek (forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> Peeker e a
peekUD UDTypeWithList e fn a itemtype
ty StackIndex
1) forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= forall e a. Property e a -> a -> LuaE e NumResults
propertyGet Property e a
prop
    forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nth CInt
3)

-- | Pushes the metatable's @setters@ field table.
pushSetters :: LuaError e => UDTypeWithList e fn a itemtype -> LuaE e ()
pushSetters :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushSetters UDTypeWithList e fn a itemtype
ty = do
  forall e. LuaE e ()
newtable
  forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ forall a b c. (a -> b -> c) -> b -> a -> c
flip forall (t :: * -> *) k a b.
Applicative t =>
(k -> a -> t b) -> Map k a -> t (Map k b)
Map.traverseWithKey (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name (Property e a)
udProperties UDTypeWithList e fn a itemtype
ty) forall a b. (a -> b) -> a -> b
$ \Name
name Property e a
prop -> do
    forall e. Name -> LuaE e ()
pushName Name
name
    forall e. CFunction -> LuaE e ()
pushcfunction forall a b. (a -> b) -> a -> b
$ case forall e a. Property e a -> Maybe (StackIndex -> a -> LuaE e a)
propertySet Property e a
prop of
      Just StackIndex -> a -> LuaE e a
_  -> CFunction
hslua_udsetter_ptr
      Maybe (StackIndex -> a -> LuaE e a)
Nothing -> CFunction
hslua_udreadonly_ptr
    forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nth CInt
3)

-- | Pushes the metatable's @methods@ field table.
pushMethods :: LuaError e => UDTypeWithList e fn a itemtype -> LuaE e ()
pushMethods :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushMethods UDTypeWithList e fn a itemtype
ty = do
  forall e. LuaE e ()
newtable
  forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ forall a b c. (a -> b -> c) -> b -> a -> c
flip forall (t :: * -> *) k a b.
Applicative t =>
(k -> a -> t b) -> Map k a -> t (Map k b)
Map.traverseWithKey (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name fn
udMethods UDTypeWithList e fn a itemtype
ty) forall a b. (a -> b) -> a -> b
$ \Name
name fn
fn -> do
    forall e. Name -> LuaE e ()
pushName Name
name
    forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> fn -> LuaE e ()
udFnPusher UDTypeWithList e fn a itemtype
ty fn
fn
    forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nth CInt
3)

pushAliases :: LuaError e => UDTypeWithList e fn a itemtype -> LuaE e ()
pushAliases :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushAliases UDTypeWithList e fn a itemtype
ty = do
  forall e. LuaE e ()
newtable
  forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ forall a b c. (a -> b -> c) -> b -> a -> c
flip forall (t :: * -> *) k a b.
Applicative t =>
(k -> a -> t b) -> Map k a -> t (Map k b)
Map.traverseWithKey (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map AliasIndex Alias
udAliases UDTypeWithList e fn a itemtype
ty) forall a b. (a -> b) -> a -> b
$ \AliasIndex
name Alias
propSeq -> do
    forall e. Pusher e AliasIndex
pushAliasIndex AliasIndex
name
    forall e a. LuaError e => Pusher e a -> [a] -> LuaE e ()
pushList forall e. Pusher e AliasIndex
pushAliasIndex Alias
propSeq
    forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nth CInt
3)

pushAliasIndex :: Pusher e AliasIndex
pushAliasIndex :: forall e. Pusher e AliasIndex
pushAliasIndex = \case
  StringIndex Name
name -> forall e. Name -> LuaE e ()
pushName Name
name
  IntegerIndex Integer
n   -> forall a e. (Integral a, Show a) => a -> LuaE e ()
pushIntegral Integer
n

-- | Pushes the function used to iterate over the object's key-value
-- pairs in a generic *for* loop.
pairsFunction :: forall e fn a itemtype. LuaError e
              => UDTypeWithList e fn a itemtype -> LuaE e NumResults
pairsFunction :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e NumResults
pairsFunction UDTypeWithList e fn a itemtype
ty = do
  a
obj <- forall e a. LuaError e => Peek e a -> LuaE e a
forcePeek forall a b. (a -> b) -> a -> b
$ forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> Peeker e a
peekUD UDTypeWithList e fn a itemtype
ty (CInt -> StackIndex
nthBottom CInt
1)
  let pushMember :: Member e fn a -> LuaE e NumResults
pushMember = \case
        MemberProperty Name
name Property e a
prop -> do
          forall e. Name -> LuaE e ()
pushName Name
name
          NumResults
getresults <- forall e a. Property e a -> a -> LuaE e NumResults
propertyGet Property e a
prop a
obj
          if NumResults
getresults forall a. Eq a => a -> a -> Bool
== NumResults
0
            then NumResults
0 forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall e. Int -> LuaE e ()
pop Int
1  -- property is absent, don't push anything
            else forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ NumResults
getresults forall a. Num a => a -> a -> a
+ NumResults
1
        MemberMethod Name
name fn
f -> do
          forall e. Name -> LuaE e ()
pushName Name
name
          forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> fn -> LuaE e ()
udFnPusher UDTypeWithList e fn a itemtype
ty fn
f
          forall (m :: * -> *) a. Monad m => a -> m a
return NumResults
2
        MemberAlias{} -> forall (m :: * -> *) a. MonadFail m => String -> m a
fail String
"aliases are not full properties"
  forall a e.
LuaError e =>
(a -> LuaE e NumResults) -> [a] -> LuaE e NumResults
pushIterator Member e fn a -> LuaE e NumResults
pushMember forall a b. (a -> b) -> a -> b
$
    forall a b. (a -> b) -> [a] -> [b]
map (forall a b c. (a -> b -> c) -> (a, b) -> c
uncurry forall e fn a. Name -> Property e a -> Member e fn a
MemberProperty) (forall k a. Map k a -> [(k, a)]
Map.toAscList (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name (Property e a)
udProperties UDTypeWithList e fn a itemtype
ty)) forall a. [a] -> [a] -> [a]
++
    forall a b. (a -> b) -> [a] -> [b]
map (forall a b c. (a -> b -> c) -> (a, b) -> c
uncurry forall e fn a. Name -> fn -> Member e fn a
MemberMethod) (forall k a. Map k a -> [(k, a)]
Map.toAscList (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name fn
udMethods UDTypeWithList e fn a itemtype
ty))

-- | Evaluate part of a lazy list. Takes the following arguments, in
-- this order:
--
-- 1. userdata wrapping the unevalled part of the lazy list
-- 2. index of the last evaluated element
-- 3. index of the requested element
-- 4. the caching table
lazylisteval :: forall itemtype e. LuaError e
             => Pusher e itemtype -> LuaE e NumResults
lazylisteval :: forall itemtype e.
LuaError e =>
Pusher e itemtype -> LuaE e NumResults
lazylisteval Pusher e itemtype
pushItem = do
  Maybe [itemtype]
munevaled <- forall a e. StackIndex -> Name -> LuaE e (Maybe a)
fromuserdata @[itemtype] (CInt -> StackIndex
nthBottom CInt
1) Name
lazyListStateName
  Maybe Integer
mcurindex <- forall e. StackIndex -> LuaE e (Maybe Integer)
tointeger (CInt -> StackIndex
nthBottom CInt
2)
  Maybe Integer
mnewindex <- forall e. StackIndex -> LuaE e (Maybe Integer)
tointeger (CInt -> StackIndex
nthBottom CInt
3)
  case (Maybe [itemtype]
munevaled, Maybe Integer
mcurindex, Maybe Integer
mnewindex) of
    (Just [itemtype]
unevaled, Just Integer
curindex, Just Integer
newindex) -> do
      let numElems :: Int
numElems = forall a b. (Integral a, Num b) => a -> b
fromIntegral forall a b. (a -> b) -> a -> b
$ forall a. Ord a => a -> a -> a
max (Integer
newindex forall a. Num a => a -> a -> a
- Integer
curindex) Integer
0
          ([itemtype]
as, [itemtype]
rest) = forall a. Int -> [a] -> ([a], [a])
splitAt Int
numElems [itemtype]
unevaled
      if forall (t :: * -> *) a. Foldable t => t a -> Bool
null [itemtype]
rest
        then do
          -- no more elements in list; unset variable
          forall e. Name -> LuaE e ()
pushName Name
"__lazylistindex"
          forall e. Pusher e Bool
pushBool Bool
False
          forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nthBottom CInt
4)
        else do
          -- put back remaining unevalled list
          forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ forall a e. StackIndex -> Name -> a -> LuaE e Bool
putuserdata @[itemtype] (CInt -> StackIndex
nthBottom CInt
1) Name
lazyListStateName [itemtype]
rest
          forall e. Name -> LuaE e ()
pushName Name
"__lazylistindex"
          forall e. Integer -> LuaE e ()
pushinteger (Integer
curindex forall a. Num a => a -> a -> a
+ forall a b. (Integral a, Num b) => a -> b
fromIntegral (forall (t :: * -> *) a. Foldable t => t a -> Int
length [itemtype]
as))
          forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nthBottom CInt
4)
      -- push evaluated elements
      forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
t a -> (a -> m b) -> m ()
forM_ (forall a b. [a] -> [b] -> [(a, b)]
zip [(Integer
curindex forall a. Num a => a -> a -> a
+ Integer
1)..] [itemtype]
as) forall a b. (a -> b) -> a -> b
$ \(Integer
i, itemtype
a) -> do
        Pusher e itemtype
pushItem itemtype
a
        forall e. LuaError e => StackIndex -> Integer -> LuaE e ()
rawseti (CInt -> StackIndex
nthBottom CInt
4) Integer
i
      forall (m :: * -> *) a. Monad m => a -> m a
return (CInt -> NumResults
NumResults CInt
0)
    (Maybe [itemtype], Maybe Integer, Maybe Integer)
_ -> forall (f :: * -> *) a. Applicative f => a -> f a
pure (CInt -> NumResults
NumResults CInt
0)

-- | Name of the metatable used for unevaluated lazy list rema
lazyListStateName :: Name
lazyListStateName :: Name
lazyListStateName = Name
"HsLua unevalled lazy list"

-- | Pushes a userdata value of the given type.
pushUD :: LuaError e => UDTypeWithList e fn a itemtype -> a -> LuaE e ()
pushUD :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> a -> LuaE e ()
pushUD UDTypeWithList e fn a itemtype
ty a
x = do
  forall a e. a -> Int -> LuaE e ()
newhsuserdatauv a
x Int
1
  forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> LuaE e ()
pushUDMetatable UDTypeWithList e fn a itemtype
ty
  forall e. StackIndex -> LuaE e ()
setmetatable (CInt -> StackIndex
nth CInt
2)
  -- add list as value in caching table
  case forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Maybe (ListSpec e a itemtype)
udListSpec UDTypeWithList e fn a itemtype
ty of
    Maybe (ListSpec e a itemtype)
Nothing -> forall (f :: * -> *) a. Applicative f => a -> f a
pure ()
    Just ((Pusher e itemtype
_, a -> [itemtype]
toList), (Peeker e itemtype, a -> [itemtype] -> a)
_) -> do
      forall e. LuaE e ()
newtable
      forall e. Name -> LuaE e ()
pushName Name
"__lazylist"
      forall a e. a -> Int -> LuaE e ()
newhsuserdatauv (a -> [itemtype]
toList a
x) Int
1
      forall (f :: * -> *) a. Functor f => f a -> f ()
void (forall e. Name -> LuaE e Bool
newudmetatable Name
lazyListStateName)
      forall e. StackIndex -> LuaE e ()
setmetatable (CInt -> StackIndex
nth CInt
2)
      forall e. LuaError e => StackIndex -> LuaE e ()
rawset (CInt -> StackIndex
nth CInt
3)
      forall (f :: * -> *) a. Functor f => f a -> f ()
void (forall e. StackIndex -> Int -> LuaE e Bool
setiuservalue (CInt -> StackIndex
nth CInt
2) Int
1)

-- | Retrieves a userdata value of the given type.
peekUD :: LuaError e => UDTypeWithList e fn a itemtype -> Peeker e a
peekUD :: forall e fn a itemtype.
LuaError e =>
UDTypeWithList e fn a itemtype -> Peeker e a
peekUD UDTypeWithList e fn a itemtype
ty StackIndex
idx = do
  let name :: Name
name = forall e fn a itemtype. UDTypeWithList e fn a itemtype -> Name
udName UDTypeWithList e fn a itemtype
ty
  a
x <- forall e a. Name -> (StackIndex -> LuaE e (Maybe a)) -> Peeker e a
reportValueOnFailure Name
name (forall a e. StackIndex -> Name -> LuaE e (Maybe a)
`fromuserdata` Name
name) StackIndex
idx
  (forall e a b. Peek e a -> LuaE e b -> Peek e a
`lastly` forall e. Int -> LuaE e ()
pop Int
1) forall a b. (a -> b) -> a -> b
$ forall e a. LuaE e a -> Peek e a
liftLua (forall e. StackIndex -> Int -> LuaE e Type
getiuservalue StackIndex
idx Int
1) forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
    Type
TypeTable -> do
      -- set list
      a
xWithList <- forall b a. b -> (a -> b) -> Maybe a -> b
maybe forall (f :: * -> *) a. Applicative f => a -> f a
pure forall itemtype e a.
LuaError e =>
ListSpec e a itemtype -> a -> Peek e a
setList (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Maybe (ListSpec e a itemtype)
udListSpec UDTypeWithList e fn a itemtype
ty) a
x
      forall e a. LuaE e a -> Peek e a
liftLua forall a b. (a -> b) -> a -> b
$ do
        forall e. LuaE e ()
pushnil
        forall e a. LuaError e => Map Name (Property e a) -> a -> LuaE e a
setProperties (forall e fn a itemtype.
UDTypeWithList e fn a itemtype -> Map Name (Property e a)
udProperties UDTypeWithList e fn a itemtype
ty) a
xWithList
    Type
_ -> forall (m :: * -> *) a. Monad m => a -> m a
return a
x

-- | Retrieves object properties from a uservalue table and sets them on
-- the given value. Expects the uservalue table at the top of the stack.
setProperties :: LuaError e => Map Name (Property e a) -> a -> LuaE e a
setProperties :: forall e a. LuaError e => Map Name (Property e a) -> a -> LuaE e a
setProperties Map Name (Property e a)
props a
x = do
  Bool
hasNext <- forall e. StackIndex -> LuaE e Bool
Unsafe.next (CInt -> StackIndex
nth CInt
2)
  if Bool -> Bool
not Bool
hasNext
    then forall (m :: * -> *) a. Monad m => a -> m a
return a
x
    else forall e. StackIndex -> LuaE e Type
ltype (CInt -> StackIndex
nth CInt
2) forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
      Type
TypeString -> do
        Name
propName <- forall e a. LuaError e => Peek e a -> LuaE e a
forcePeek forall a b. (a -> b) -> a -> b
$ forall e. Peeker e Name
peekName (CInt -> StackIndex
nth CInt
2)
        case forall k a. Ord k => k -> Map k a -> Maybe a
Map.lookup Name
propName Map Name (Property e a)
props forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= forall e a. Property e a -> Maybe (StackIndex -> a -> LuaE e a)
propertySet of
          Maybe (StackIndex -> a -> LuaE e a)
Nothing -> forall e. Int -> LuaE e ()
pop Int
1 forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> forall e a. LuaError e => Map Name (Property e a) -> a -> LuaE e a
setProperties Map Name (Property e a)
props a
x
          Just StackIndex -> a -> LuaE e a
setter -> do
            a
x' <- StackIndex -> a -> LuaE e a
setter StackIndex
top a
x
            forall e. Int -> LuaE e ()
pop Int
1
            forall e a. LuaError e => Map Name (Property e a) -> a -> LuaE e a
setProperties Map Name (Property e a)
props a
x'
      Type
_ -> a
x forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall e. Int -> LuaE e ()
pop Int
1

-- | Gets a list from a uservalue table and sets it on the given value.
-- Expects the uservalue (i.e., caching) table to be at the top of the
-- stack.
setList :: forall itemtype e a. LuaError e
        => ListSpec e a itemtype -> a
        -> Peek e a
setList :: forall itemtype e a.
LuaError e =>
ListSpec e a itemtype -> a -> Peek e a
setList ((Pusher e itemtype, a -> [itemtype])
_pushspec, (Peeker e itemtype
peekItem, a -> [itemtype] -> a
updateList)) a
x = (a
x a -> [itemtype] -> a
`updateList`) forall (m :: * -> *) a b. Monad m => (a -> b) -> m a -> m b
<$!> do
  forall e a. LuaE e a -> Peek e a
liftLua (forall e. LuaError e => StackIndex -> Name -> LuaE e Type
getfield StackIndex
top Name
"__lazylistindex") forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
    Type
TypeBoolean -> do
      -- list had been fully evaluated
      forall e a. LuaE e a -> Peek e a
liftLua forall a b. (a -> b) -> a -> b
$ forall e. Int -> LuaE e ()
pop Int
1
      forall a e. LuaError e => Peeker e a -> Peeker e [a]
peekList Peeker e itemtype
peekItem StackIndex
top
    Type
_ -> do
      let getLazyList :: Peek e [itemtype]
getLazyList = do
            forall e a. LuaE e a -> Peek e a
liftLua (forall e. LuaError e => StackIndex -> Name -> LuaE e Type
getfield StackIndex
top Name
"__lazylist") forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
              Type
TypeUserdata -> forall (f :: * -> *) a. Applicative f => a -> f a
pure ()
              Type
_ -> forall a e. ByteString -> Peek e a
failPeek ByteString
"unevaled items of lazy list cannot be peeked"
            (forall e a b. Peek e a -> LuaE e b -> Peek e a
`lastly` forall e. Int -> LuaE e ()
pop Int
1) forall a b. (a -> b) -> a -> b
$ forall e a. Name -> (StackIndex -> LuaE e (Maybe a)) -> Peeker e a
reportValueOnFailure
              Name
lazyListStateName
              (\StackIndex
idx -> forall a e. StackIndex -> Name -> LuaE e (Maybe a)
fromuserdata @[itemtype] StackIndex
idx Name
lazyListStateName)
              StackIndex
top
      Maybe Integer
mlastIndex <- forall e a. LuaE e a -> Peek e a
liftLua (forall e. StackIndex -> LuaE e (Maybe Integer)
tointeger StackIndex
top forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* forall e. Int -> LuaE e ()
pop Int
1)
      let itemsAfter :: Integer -> Peek e [itemtype]
itemsAfter = case Maybe Integer
mlastIndex of
            Maybe Integer
Nothing -> forall a b. a -> b -> a
const Peek e [itemtype]
getLazyList
            Just Integer
lastIndex -> \Integer
i ->
              if Integer
i forall a. Ord a => a -> a -> Bool
<= Integer
lastIndex
              then forall e a. LuaE e a -> Peek e a
liftLua (forall e. LuaError e => StackIndex -> Integer -> LuaE e Type
rawgeti StackIndex
top Integer
i) forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
                Type
TypeNil -> [] forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall e a. LuaE e a -> Peek e a
liftLua (forall e. Int -> LuaE e ()
pop Int
1)
                Type
_ -> do
                  itemtype
y <- Peeker e itemtype
peekItem StackIndex
top forall e a b. Peek e a -> LuaE e b -> Peek e a
`lastly` forall e. Int -> LuaE e ()
pop Int
1
                  (itemtype
yforall a. a -> [a] -> [a]
:) forall (m :: * -> *) a b. Monad m => (a -> b) -> m a -> m b
<$!> Integer -> Peek e [itemtype]
itemsAfter (Integer
i forall a. Num a => a -> a -> a
+ Integer
1)
              else Peek e [itemtype]
getLazyList
      Integer -> Peek e [itemtype]
itemsAfter Integer
1