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#ifndef LUA_FUNC_H

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#define LUA_FUNC_H

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/**

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 * @file

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 *

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 * Convenience functions for working with lua C functions

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 */

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#include "lua_type.h"

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#include <stdbool.h>

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/**

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 * Lua function argument types

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 */

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enum lua_arg_type {

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    LUA_ARG_INVALID,

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    /** A `const char *` pointing to lua-GC'd memory */

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    LUA_ARG_STRING,

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    /** A c99 `bool` */

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    LUA_ARG_BOOL,

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    /** A `long signed int` */

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    LUA_ARG_INT,

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};

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/**

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 * Function argument def

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 */

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struct lua_func_arg {

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    /** Argument name */

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    const char *name;

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    /** Expected type */

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    enum lua_arg_type type;

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    /** Default value */

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    union {

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        const char *string;

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        int boolean;

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        long integer;

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    } def;

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};

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/**

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 * Function def

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 */

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struct lua_func {

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    /** Object type, or NULL */

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    const struct lua_type *type;

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    /** Function name */

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    const char *name;

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    /** Help string */

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    const char *help;

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    /** Arguments */

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    const struct lua_func_arg args[];

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};

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/**

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 * Used as the "invalid" default value

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 */

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#define LUA_ARG_REQUIRED (-1)

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#define LUA_ARG_STRING_REQUIRED ((const char *) (-1))

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/**

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 * Define a function argument

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 */

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#define LUA_FUNC_ARG_STRING(name, def) { (name), LUA_ARG_STRING, { .string = (def) } }

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#define LUA_FUNC_ARG_BOOL(name, def) { (name), LUA_ARG_BOOL, { .boolean = (def) } }

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#define LUA_FUNC_ARG_INT(name, def) { (name), LUA_ARG_INT, { .integer = (def) } }

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#define LUA_FUNC_ARG_END { NULL, 0, { 0 } }

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/**

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 * Define a function

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 */

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#define LUA_FUNC(type, name, help, ...) { (type), (name), (help), { __VA_ARGS__, LUA_FUNC_ARG_END } }

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/**

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 * Parse and return a string argument

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 */

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const char *lua_arg_string (lua_State *L, int nargs, int index, const char *name, const char *def);

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/**

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 * Parse and return a boolean argument

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 */

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bool lua_arg_bool (lua_State *L, int nargs, int index, const char *name, int def);

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/**

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 * Parse and return an integer argument

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 */

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long lua_arg_int (lua_State *L, int nargs, int index, const char *name, long def);

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/**

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 * Return a userdata argument at the given fixed index

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 */

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void* lua_arg_obj (lua_State *L, int nargs, int index, const struct lua_type *type, bool optional);

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/**

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 * Parse function arguments as defined

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 */

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void lua_args_parse (lua_State *L, const struct lua_func *func, void **obj_ptr, ...);

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#endif