Plugin Reference

There are some general macros essential to interfacing with Gwion in general.

The return codes of functions are of type m_bool and consist of the following values:

Name	Value	Description
`GW_OK`	1	Success
`GW_PASS`	0	Ignore the result and continue
`GW_ERROR`	-1	An error occured

The following macros are sugar for handling error codes. They can exit the scope of the function. It is recommended to use these rather than writing:

if (!a) return NULL;

and co.

Name	Value	Description
`CHECK_BB`	`if (f < 0) return GW_ERROR;`	Takes an expression that evaluates to `m_bool`. Potentially exits function returning `GW_ERROR`.
`CHECK_BO`	`if (f < 0) return NULL;`	Takes an expression that evaluates to `m_bool`. Potentially exits function returning `NULL`.
`CHECK_OB`	`if (!f) return GW_ERROR;`	Takes an expression that evaluates to a pointer. Potentially exits function returning `GW_ERROR`.
`CHECK_OO`	`if (!f) return NULL;`	Takes an expression that evaluates to a pointer. Potentially exits function returning `NULL`.

Likewise there are the DECL_XX macros which specialize to failing if a declaration fails. Their general syntax is as follows:

DECL_XX(type, var_name, = value);

These macros are specific to creating plugins.

MFUN(name) signature for a member function SFUN(name) signature for a static function CTOR(name) signature for a constructor DTOR(name) signature for a destructor GACK(name) signature for a pretty print function TICK(name) signature for a UGen tick function GWION_IMPORT(name) main function of a plugin/library

in said main function, one should use GWI_XX instead of CHECK_XX since it takes care of position and might optimize some checks away (in gwion's internals)

OP_CHECK(name) define a type checking function. should return correct type in success error type on failure NULL to continue type checking

OP_EMIT(name) define an emitter function. returns an m_bool