The lua package provides a Lua interpreter as well as bindings, wrappers and types to combine Haskell and Lua.
Lua is a small, well-designed, embeddable scripting language. It has become the de-facto default to make programs extensible and is widely used everywhere from servers over games and desktop applications up to security software and embedded devices. This package provides Haskell bindings to Lua, enable coders to embed the language into their programs, making them scriptable.
This package ships with the official Lua interpreter, version 5.4.8. Cabal flags allow to compile against a system-wide Lua installation instead, if desired.
The following cabal build flags are supported:
-
system-lua: Use the locally installed Lua version instead of the version shipped as part of this package. -
pkg-config: Use pkg-config to discover library and include paths. Setting this flag impliessystem-lua. -
allow-unsafe-gc: Allow optimizations which make Lua's garbage collection potentially unsafe; enabling this should be safe if there are no callbacks into Haskell during Lua garbage collection cycles. The flag should be disabled if Lua objects can have Haskell finalizers, i.e.,__gcmetamethods that call Haskell function.The flag is enabled per default, as Haskell functions are rarely used in finalizers. It can help to disable the flag if there are issues related to Lua's garbage collection.
-
apicheck: Compile Lua with its API checks enabled. -
lua_32bits: Compile Lua for a 32-bits system (e.g., i386, PowerPC G4). -
export-dynamic: Add all symbols to dynamic symbol table; disabling this will make it possible to create fully static binaries, but renders loading of dynamic C libraries impossible.
To use a system-wide installed Lua when linking lua as a
dependency, build/install your package using
--constraint="lua +system-lua". For example, you can
install Pandoc with hslua that uses system-wide Lua like this:
cabal install pandoc --constraint="lua +system-lua"or with stack:
stack install pandoc --flag=lua:system-lua