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{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE TypeApplications #-}
{- |
Module : Text.Pandoc.Lua.Marshaling.Attr
Copyright : © 2012-2021 John MacFarlane
© 2017-2021 Albert Krewinkel
License : GNU GPL, version 2 or above
Maintainer : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
Stability : alpha
Marshaling/unmarshaling instances for document AST elements.
-}
module Text.Pandoc.Lua.Marshaling.Attr
( typeAttr
, peekAttr
, pushAttr
, mkAttr
, mkAttributeList
) where
import Control.Applicative ((<|>), optional)
import Control.Monad ((<$!>))
import Data.Maybe (fromMaybe)
import Data.Text (Text)
import HsLua
import HsLua.Marshalling.Peekers (peekIndexRaw)
import Safe (atMay)
import Text.Pandoc.Definition (Attr, nullAttr)
import Text.Pandoc.Lua.Marshaling.List (pushPandocList)
import qualified Data.Text as T
typeAttr :: LuaError e => DocumentedType e Attr
typeAttr = deftype "Attr"
[ operation Eq $ lambda
### liftPure2 (==)
<#> parameter peekAttr "a1" "Attr" ""
<#> parameter peekAttr "a2" "Attr" ""
=#> functionResult pushBool "boolean" "whether the two are equal"
, operation Tostring $ lambda
### liftPure show
<#> parameter peekAttr "Attr" "attr" ""
=#> functionResult pushString "string" "native Haskell representation"
]
[ property "identifier" "element identifier"
(pushText, \(ident,_,_) -> ident)
(peekText, \(_,cls,kv) -> (,cls,kv))
, property "classes" "element classes"
(pushPandocList pushText, \(_,classes,_) -> classes)
(peekList peekText, \(ident,_,kv) -> (ident,,kv))
, property "attributes" "various element attributes"
(pushAttribs, \(_,_,attribs) -> attribs)
(peekAttribs, \(ident,cls,_) -> (ident,cls,))
, method $ defun "clone"
### return
<#> parameter peekAttr "attr" "Attr" ""
=#> functionResult pushAttr "Attr" "new Attr element"
, readonly "tag" "element type tag (always 'Attr')"
(pushText, const "Attr")
, alias "t" "alias for `tag`" ["tag"]
]
pushAttr :: LuaError e => Pusher e Attr
pushAttr = pushUD typeAttr
peekAttribs :: LuaError e => Peeker e [(Text,Text)]
peekAttribs idx = liftLua (ltype idx) >>= \case
TypeUserdata -> peekUD typeAttributeList idx
TypeTable -> liftLua (rawlen idx) >>= \case
0 -> peekKeyValuePairs peekText peekText idx
_ -> peekList (peekPair peekText peekText) idx
_ -> failPeek "unsupported type"
pushAttribs :: LuaError e => Pusher e [(Text, Text)]
pushAttribs = pushUD typeAttributeList
typeAttributeList :: LuaError e => DocumentedType e [(Text, Text)]
typeAttributeList = deftype "AttributeList"
[ operation Eq $ lambda
### liftPure2 (==)
<#> parameter peekAttribs "a1" "AttributeList" ""
<#> parameter peekAttribs "a2" "AttributeList" ""
=#> functionResult pushBool "boolean" "whether the two are equal"
, operation Index $ lambda
### liftPure2 lookupKey
<#> udparam typeAttributeList "t" "attributes list"
<#> parameter peekKey "string|integer" "key" "lookup key"
=#> functionResult (maybe pushnil pushAttribute) "string|table"
"attribute value"
, operation Newindex $ lambda
### setKey
<#> udparam typeAttributeList "t" "attributes list"
<#> parameter peekKey "string|integer" "key" "lookup key"
<#> optionalParameter peekAttribute "string|nil" "value" "new value"
=#> []
, operation Len $ lambda
### liftPure length
<#> udparam typeAttributeList "t" "attributes list"
=#> functionResult pushIntegral "integer" "number of attributes in list"
, operation Pairs $ lambda
### pushIterator (\(k, v) -> 2 <$ pushText k <* pushText v)
<#> udparam typeAttributeList "t" "attributes list"
=?> "iterator triple"
, operation Tostring $ lambda
### liftPure show
<#> udparam typeAttributeList "t" "attributes list"
=#> functionResult pushString "string" ""
]
[]
data Key = StringKey Text | IntKey Int
peekKey :: LuaError e => Peeker e (Maybe Key)
peekKey idx = liftLua (ltype idx) >>= \case
TypeNumber -> Just . IntKey <$!> peekIntegral idx
TypeString -> Just . StringKey <$!> peekText idx
_ -> return Nothing
data Attribute
= AttributePair (Text, Text)
| AttributeValue Text
pushAttribute :: LuaError e => Pusher e Attribute
pushAttribute = \case
(AttributePair kv) -> pushPair pushText pushText kv
(AttributeValue v) -> pushText v
-- | Retrieve an 'Attribute'.
peekAttribute :: LuaError e => Peeker e Attribute
peekAttribute idx = (AttributeValue <$!> peekText idx)
<|> (AttributePair <$!> peekPair peekText peekText idx)
lookupKey :: [(Text,Text)] -> Maybe Key -> Maybe Attribute
lookupKey !kvs = \case
Just (StringKey str) -> AttributeValue <$!> lookup str kvs
Just (IntKey n) -> AttributePair <$!> atMay kvs (n - 1)
Nothing -> Nothing
setKey :: forall e. LuaError e
=> [(Text, Text)] -> Maybe Key -> Maybe Attribute
-> LuaE e ()
setKey kvs mbKey mbValue = case mbKey of
Just (StringKey str) ->
case break ((== str) . fst) kvs of
(prefix, _:suffix) -> case mbValue of
Nothing -> setNew $ prefix ++ suffix
Just (AttributeValue value) -> setNew $ prefix ++ (str, value):suffix
_ -> failLua "invalid attribute value"
_ -> case mbValue of
Nothing -> return ()
Just (AttributeValue value) -> setNew (kvs ++ [(str, value)])
_ -> failLua "invalid attribute value"
Just (IntKey idx) ->
case splitAt (idx - 1) kvs of
(prefix, (k,_):suffix) -> setNew $ case mbValue of
Nothing -> prefix ++ suffix
Just (AttributePair kv) -> prefix ++ kv : suffix
Just (AttributeValue v) -> prefix ++ (k, v) : suffix
(prefix, []) -> case mbValue of
Nothing -> setNew prefix
Just (AttributePair kv) -> setNew $ prefix ++ [kv]
_ -> failLua $ "trying to set an attribute key-value pair, "
++ "but got a single string instead."
_ -> failLua "invalid attribute key"
where
setNew :: [(Text, Text)] -> LuaE e ()
setNew new =
putuserdata (nthBottom 1) (udName @e typeAttributeList) new >>= \case
True -> return ()
False -> failLua "failed to modify attributes list"
peekAttr :: LuaError e => Peeker e Attr
peekAttr idx = retrieving "Attr" $ liftLua (ltype idx) >>= \case
TypeString -> (,[],[]) <$!> peekText idx -- treat string as ID
TypeUserdata -> peekUD typeAttr idx
TypeTable -> peekAttrTable idx
x -> liftLua . failLua $ "Cannot get Attr from " ++ show x
-- | Helper function which gets an Attr from a Lua table.
peekAttrTable :: LuaError e => Peeker e Attr
peekAttrTable idx = do
len' <- liftLua $ rawlen idx
let peekClasses = peekList peekText
if len' > 0
then do
ident <- peekIndexRaw 1 peekText idx
classes <- fromMaybe [] <$!> optional (peekIndexRaw 2 peekClasses idx)
attribs <- fromMaybe [] <$!> optional (peekIndexRaw 3 peekAttribs idx)
return $ ident `seq` classes `seq` attribs `seq`
(ident, classes, attribs)
else retrieving "HTML-like attributes" $ do
kvs <- peekKeyValuePairs peekText peekText idx
let ident = fromMaybe "" $ lookup "id" kvs
let classes = maybe [] T.words $ lookup "class" kvs
let attribs = filter ((`notElem` ["id", "class"]) . fst) kvs
return $ ident `seq` classes `seq` attribs `seq`
(ident, classes, attribs)
-- | Constructor for 'Attr'.
mkAttr :: LuaError e => DocumentedFunction e
mkAttr = defun "Attr"
### (ltype (nthBottom 1) >>= \case
TypeString -> forcePeek $ do
mident <- optional (peekText (nthBottom 1))
mclass <- optional (peekList peekText (nthBottom 2))
mattribs <- optional (peekAttribs (nthBottom 3))
return ( fromMaybe "" mident
, fromMaybe [] mclass
, fromMaybe [] mattribs)
TypeTable -> forcePeek $ peekAttrTable (nthBottom 1)
TypeUserdata -> forcePeek $ peekUD typeAttr (nthBottom 1) <|> do
attrList <- peekUD typeAttributeList (nthBottom 1)
return ("", [], attrList)
TypeNil -> pure nullAttr
TypeNone -> pure nullAttr
x -> failLua $ "Cannot create Attr from " ++ show x)
=#> functionResult pushAttr "Attr" "new Attr object"
-- | Constructor for 'AttributeList'.
mkAttributeList :: LuaError e => DocumentedFunction e
mkAttributeList = defun "AttributeList"
### return
<#> parameter peekAttribs "table|AttributeList" "attribs" "an attribute list"
=#> functionResult (pushUD typeAttributeList) "AttributeList"
"new AttributeList object"
|
