haskell - 使用 c2hs 与结构和匿名联合进行交互

Question

如何在 .chs 文件中编码这段 C 代码，以便 c2hs 可以将其转换为相对较好的东西？

typedef enum {
    MONOME_BUTTON_UP        = 0x00,
    MONOME_BUTTON_DOWN      = 0x01,
    MONOME_ENCODER_DELTA    = 0x02,
    MONOME_ENCODER_KEY_UP   = 0x03,
    MONOME_ENCODER_KEY_DOWN = 0x04,
    MONOME_TILT             = 0x05,

    /* update this if you add event types */
    MONOME_EVENT_MAX        = 0x06
} monome_event_type_t;

typedef struct monome monome_t; /* opaque data type */
typedef struct monome_event monome_event_t;

typedef void (*monome_event_callback_t)
    (const monome_event_t *event, void *data);

struct monome_event {
    monome_t *monome;
    monome_event_type_t event_type;

    /* __extension__ for anonymous unions in gcc */
    __extension__ union {
        struct {
            unsigned int x;
            unsigned int y;
        } grid;

        struct {
            unsigned int number;
            int delta;
        } encoder;

        struct {
            unsigned int sensor;
            int x;
            int y;
            int z;
        } tilt;
    };
};

Answer 1

怎么样：更改代码以便为成员命名。内存中的布局是相同的，因此它将是二进制兼容的。你必须为每个版本的库做这个补丁。

struct monome_event {
    monome_t *monome;
    monome_event_type_t event_type;

    /* __extension__ for anonymous unions in gcc */
    __extension__ union {
        struct me_grid {
            unsigned int x;
            unsigned int y;
        } grid;

        struct me_encoder {
            unsigned int number;
            int delta;
        } encoder;

        struct me_tilt {
            unsigned int sensor;
            int x;
            int y;
            int z;
        } tilt;
    };
};