*To avoid a duplication of efforts, ziglua does not contain full documentation on the Lua C API. Please refer to [the Lua C API Documentation](https://www.lua.org/manual/5.4/manual.html#4) for full details.*
In general, most functions are named similarly to the original C functions. The `lua_` and `luaL_` prefixes have been removed, because all functions are in the `Lua` struct namespace. Additionally, all functions are in `camelCase` to match Zig naming style.
In the few cases when the [auxiliary library](https://www.lua.org/manual/5.4/manual.html#5) functions have the same name as a normal C API function, the suffix `Aux` is added to the function name to distinguish from the normal function.
For example, the functions `lua_newstate` and `luaL_newstate` are translated to `Lua.newState` and `Lua.newStateAux` respectively.
In the C API, there are two functions provided to initialize the main Lua state: `lua_newstate` and `luaL_newstate`. The former requires passing an allocator function to be used by Lua for all memory allocations, while the latter uses the default libc allocator.
Ziglua provides a third option with the `Lua.init(Allocator)` function, which accepts a traditional Zig allocator. All three functions are available depending on your needs, but most likely you will want to use the `init` function. If you have special requirements for allocation, then `Lua.newState` would be useful. `Lua.newStateAux` is available, but Zig cannot track allocations made by libc so this is less safe.
The ziglua API aims to be safer than the traditional C API. That said, the way that Lua operates means that Zig cannot protect you from all errors due to the use of `longjmp` in C.
Here is a list of the types of features ziglua uses to ensure greater safety:
### Errors
Many functions now return Zig errors rather than an integer code. The compiler will then ensure that the error is handled, or ignored. There are specific error types like `ziglua.Error.Runtime` for errors that have a specific meaning.
On the other hand, many functions either succeed or return an error. Rather than returning a boolean success code, these functions return the generic `ziglua.Error.Fail` to indicate failure. The type of failure can be determined in the context of the function called.
### Booleans
Functions that return or accept C boolean integers now use the Zig `bool` type to increase type safety.
### Slices
In cases where C functions use separate pointers and ints to keep track of strings, ziglua uses a Zig slice to keep the data together.
The slices are typed to indicate the contents (zero-terminated, raw bytes, etc)
### Enums
ziglua uses enums instead of enumerated integer codes to ensure all cases are handled, and to prevent passing an invalid integer type to a function.
### Optionals
Any value that can be `NULL` in the C API is marked as optional in Zig to enforce null checking.
All functions and types that deal with continuations have been renamed. For example, `KFunction` is now `LuaContFn`, and `lua_yieldk` is now `yieldCont`. One exception is the `KContext` type which has been simply renamed to `Context`. This is only ever used in continuation functions, so the `K` doesn't add much detail.
The "string" variant functions vs the "lstring" functions only differ by returning the length of the string. In ziglua, the lstring functions are all named "bytes" instead. For example, `lua_tolstring` is `Lua.toBytes`. This is because these functions are typically used in cases when the string _might_ contain zeros before the null-terminating zero.
The "string" variant functions are safe to use when the string is known to be null terminated without inner zeros.
The length of the returned string is almost always needed, so `Lua.toString() returns a zero-terminated Zig slice of the bytes with the correct length.
### `lua_tointegerx` and `lua_tonumberx`
Both of these functions accept an `isnum` return parameter to indicate if the conversion to number was successful. In the Zig version, both functions return either the number, or an error indicating the conversion was unsuccessful, and the `isnum` parameter is omitted.
### `lua_pushliteral`
This is just a macro for `lua_pushstring`, so just use `Lua.pushString()` instead.
There is currently one option that can be passed in the third argument to `ziglua.link()`:
*`.use_apicheck`: defaults to **false**. When **true** defines the macro `LUA_USE_APICHECK` in debug builds. See [The C API docs](https://www.lua.org/manual/5.4/manual.html#4) for more information on this macro.
## Examples
Here are more thorough examples that show off the ziglua bindings in context. All examples use previously documented [`build.zig`](#build-documentation) setup.
Notice that the functions `lua.loadString()` and `lua.protectedCall()` return errors that must be handled, here printing the error message that was placed on the stack.
Notice the use of `ziglua.wrap`. This is because the function `fn adder(*Lua) i32` is a `ziglua.ZigFn`, when the `lua.pushFunction` call expects a `ziglua.CFn` type.
The `ziglua.wrap` function generates a new function at compile time that wraps the Zig function in a function compatible with the Lua C API. This could be done automatically by `lua.pushFunction`, but that would require the parameter to be comptime-known. The call to `ziglua.wrap` is slightly more verbose, but has the benefit of being more flexible.