typedef JSBool (*JSNative)(JSContext *cx, JSObject *obj, unsigned int argc, jsval *argv, jsval *rval)

typedef JSBool (JSNative)(JSContext cx, JSObject obj, unsigned int argc, jsval argv, jsval *rval)

Description The function signature for C-level implementations of JavaScript functions, where:

	`cx` is a pointer to an opaque `JSContext` structure, which must be passed to some of the functions in the JavaScript API. This variable holds the interpreter's execution context.
	`obj` is a pointer to the object in whose context the script executes. While the script is running, the `this` keyword is equal to this object.
	`argc` is the number of arguments being passed to the function.
	`argv` is a pointer to an array of `jsvals`. The array is `argc` elements in length.
	`rval` is a pointer to a single `jsval`. The function's return value should be written to `*rval`.

The function returns JS_TRUE upon success or JS_FALSE upon failure. If JS_FALSE is returned, the current script stops executing.