Text.Pandoc.Lua.Marshal.Filter

Marshaling/unmarshaling functions Lua filters, i.e., tables containing functions to be called on specific elements.

Filters

data Filter

Collection of filter functions (at most one function per element constructor)

Constructors

Filter

Fields

• filterWalkingOrder :: WalkingOrder
• filterMap :: Map Name FilterFunction

data WalkingOrder

Description of how an AST should be traversed.

Constructors

WalkForEachType

Process each type separately, traversing the tree bottom-up (leaves to root) for each type.

WalkTopdown

Traverse the tree top-down, from root to leaves and depth first, in a single traversal.

peekFilter :: LuaError e => Peeker e Filter

Retrieves a default Filter object from the stack, suitable for filtering a full document.

lookup :: Name -> Filter -> Maybe FilterFunction

Looks up a filter function in a Lua Filter.

member :: Name -> Filter -> Bool

Checks whether the Filter contains a function of the given name.

Individual filter functions

newtype FilterFunction

Filter function stored in the registry

Constructors

FilterFunction Reference

peekFilterFunction :: Peeker e FilterFunction

Retrieves a filter function from the stack.

The value at the given index must be a function. It is stored in the Lua registry.

pushFilterFunction :: LuaError e => FilterFunction -> LuaE e ()

Pushes a filter function to the stack.

Filter functions are stored in the registry and retrieved from there.

getFunctionFor :: forall a. Data a => Filter -> a -> Maybe FilterFunction

Finds the best filter function for a given element; returns Nothing if no such function exists.

Names in filter functions

baseFunctionName :: forall a. Data a => Proxy a -> Name

The name of a type's base function, which is called if there is no more specific function for a value.

listFunctionName :: forall a. Data a => Proxy a -> Name

The name of the functions that's called on lists of the given type.

valueFunctionNames :: forall a. Data a => Proxy a -> [Name]

Filter function names for a given type.