Lua

A Swift wraper for Lua 5.2.4

Not every feature is implemented, and the API is not yet stable Feel free to open a new issue or pull request

Types

Lua values are wrapped within the Value protocol when brought into Swift

String

Swift's String is used to represent Lua strings

Number

The Number class represents a numeric value within Lua. It supports conversion to Int, UInt32, and Double as well as comparisons with those types.

• .intValue -> Int
• .uintValue -> UInt32
• .doubleValue -> Double
• .isInt -> Bool true if .doubleValue contains no decimal places

UnsafeMutablePointer

Swift's UnsafeMutablePointer is used to represent Lua lightuserdatas

Table

The Table class represents a table within Lua. It supports getting and setting values.

• subscript(Value) -> Value get and set values
• forEach(body: (TableKey, Value) -> Void) iterate over all key/value pairs in
• toDictionary() -> [TableKey : Value] fetches all of the key/value pairs from the Lua VM and returns a Dictionary

Function

The Function class represents a Lua closure. It supports calling with a list of Values

• call([Value]) -> [Value] call the function with the arguments

CustomType

It is possible to bring Swift types into Lua by creating a CustomType<T> which gives access to the new type's metatable and statictable

Nil

Represents a nil value on the stack

Typealiases

• Index = Int32
• Count = Int32
• LuaFunction = (Lua) -> [Value]
• WrappedFunction = ([Value]) -> [Value]
• LuaMethod<T> = (T, Lua) -> [Value]
• WrappedMethod<T> = (T, [Value]) -> [Value]
• LuaInitializer<T> = (Lua) -> T
• WrappedInitializer<T> = ([Value]) -> T

Usage

Lua

• Lua() create a new virtual machine
• .loadLib([LuaLib]) loads the given standard libraries
• .globals -> Table get the global value Table
• run(String) throws -> [Value] runs a String as Lua code
• push(Value) pushes a Value onto the stack
• pop() -> Value pops a Value from the stack
• createTable(Count=0, Count=0) -> Table creates and returns a new Table with optional preallocated space
• createFunction(LuaFunction) -> Function creates and returns a new Function
• createFunction([Type],WrappedFunction) -> Function creates and returns a new Function that is typechecked internally
• createType<T: LuaConvertible>(T.Type) throws -> CustomType<T> creates a new Lua type from a LuaConvertible type and returns its CustomType
• wrap<T: LuaConvertible>([Type], @escaping WrappedInitializer<T>) -> LuaInitializer<T> wraps a WrappedInitializer<T> to do typechecking internally
• wrap<T: LuaConvertible>([Type], @escaping WrappedMethod<T>) -> LuaMethod<T> wraps a WrappedMethod<T> to do typechecking internally
• wrap([Type], @escaping WrappedFunction) -> LuaFunction wraps a WrappedFunction to do typechecking internally

Lua.raw

• stackSize() -> Count returns the number of items on the Lua stack

Future Additions

• Explicit Garbage Collection
• Rename CustomType to CustomClassType and implement CustomStructType which is a Table rather than a UserData for simpler types
• Change how Function is implemented to allow them to be released without needing to release the entire Lua machine
• Complete LightUserData implementation
• Expand the capabilities of CustomType<T>
• Test UserData equality
• Add Bool support
• Support for more metamethods