meta C

meta.c

#include <stdio.h>

typedef struct true_t {
    char _;
} true_t;

true_t TRUE;

typedef struct false_t {
    char _;
} false_t;

false_t FALSE;

int f_true() {
    return 1;
}

int f_false() {
    return 0;
}

#define bool_v(B) _Generic((B *) (0), true_t *: TRUE, false_t *: FALSE)
#define bool_v_to_int(B) _Generic(B, true_t: 1, false_t: 0)

#define v_to_bool(V) typeof(V)

#define is_string_v(X) _Generic((X), \
        char *: 1,                   \
        default: 0)

#define is_string_t(X) typeof(_Generic((X), \
        char *: TRUE,                       \
        default: FALSE))


#define has_signature_v(X, R, ...)         \
    _Generic((X),                          \
            SignatureM(R, __VA_ARGS__): 1, \
            default: 0)

#define has_signature_t(X, R, ...)            \
    typeof(_Generic((X),                      \
            SignatureM(R, __VA_ARGS__): TRUE, \
            default: FALSE))

#define to_string(X) _Generic((X), \
        true_t: "true",            \
        false_t: "false")

#define has_same_type_v(X, Y)       \
    _Generic(has_same_type_t(X, Y), \
            true_t: 1,              \
            false_t: 0)

#define has_same_type_t(X, Y) typeof(_Generic((X), \
        typeof(Y): TRUE,                           \
        default: FALSE))

#define SignatureM(R, ...) R (*)(__VA_ARGS__)

#define is_same_t(X, Y)          \
    typeof(_Generic(((X *) (0)), \
            Y *: TRUE,           \
            default: FALSE))

#define and_t(X, Y)                                                    \
    typeof(_Generic(bool_v(X),                                         \
            true_t: _Generic(bool_v(Y), true_t: TRUE, false_t: FALSE), \
            false_t: _Generic(bool_v(Y), true_t: FALSE, false_t: FALSE)))

#define or_t(X, Y)                                                    \
    typeof(_Generic(bool_v(X),                                        \
            true_t: _Generic(bool_v(Y), true_t: TRUE, false_t: TRUE), \
            false_t: _Generic(bool_v(Y), true_t: TRUE, false_t: FALSE)))

#define not_t(X)               \
    typeof(_Generic(bool_v(X), \
            true_t: FALSE,     \
            false_t: TRUE))

#define result_t(X, ...) typeof((X) (__VA_ARGS__))

#define id_sig(T) SignatureM(T, void)
#define true_sig id_sig(true_t)
#define false_sig id_sig(false_t)
#define _0 false_sig
#define _1 true_sig

#define bool_sig_v(S) _Generic((S) (0), true_sig: TRUE, false_sig: FALSE)
#define bool_sig_int(S) _Generic((S) (0), true_sig: 1, false_sig: 0)
#define bool_sig_t(S) typeof(bool_sig_v(S))

#define sig_apply_res_t(X) typeof(((X) (0))())

#define is_same_sig_t(SA, SB) typeof(_Generic((SA) (0), SB: TRUE, default: FALSE))
#define eq_sig(SA, SB) id_sig(is_same_sig_t(SA, SB))

#define not_sig(SA) id_sig(typeof(_Generic((SA) (0), true_sig: FALSE, false_sig: TRUE)))
#define and_sig(SA, SB) id_sig(typeof(_Generic((SA) (0), true_sig: _Generic((SB) (0), true_sig: TRUE, false_sig: FALSE), false_sig: FALSE)))
#define or_sig(SA, SB) id_sig(typeof(_Generic((SA) (0), true_sig: TRUE, false_sig: _Generic((SB) (0), true_sig: TRUE, false_sig: FALSE))))
#define xor_sig(SA, SB) not_sig(eq_sig(SA, SB))

#define select_sig(SD0, SD1, SI) typeof(_Generic((SI) (0), _0: (SD0) (0), _1: (SD1) (0)))
#define select2_sig(SD0, SD1, SD2, SD3, SI0, SI1) select_sig(select_sig(SD0, SD2, SI1), select_sig(SD1, SD3, SI1), SI0)

#define add_sig(SDA0, SDB0, SI)  \
    select_sig(                  \
            xor_sig(SDA0, SDB0), \
            and_sig(SDA0, SDB0), \
            SI)

/**
 * ```
 *                      Result selection by index: (SI0, SI1)
 *
 * SDA0 ---------[   ]------------------------ S0  ( 0 ,  0 )
 *               [ + ]
 * SDA1 -.     .-[   ]-.                  .--- S1  ( 0 ,  1 )
 *        \   /         \                /
 *         \ /           "-[   ]--------"
 *          /.             [ + ]
 *         /  \         .--[   ]-.
 * SDB0 --"    "-[   ]."          "-[   ]   .-- C  ( 1 ,  0 )
 *               [ + ]              [ V ]--"
 * SDB1 ---------[   ]--------------[   ]     - 0  ( 1 ,  1 )
 * ```
 */

#define add2_sig(SDA0, SDA1, SDB0, SDB1, SI0, SI1)                                \
    select2_sig(                                                                  \
            add_sig(SDA0, SDB0, _0),                                              \
            add_sig(add_sig(SDA0, SDB0, _1), add_sig(SDA1, SDB1, _0), _0),        \
            or_sig(add_sig(add_sig(SDA0, SDB0, _1), add_sig(SDA1, SDB1, _0), _1), \
                   add_sig(SDA1, SDB1, _1)),                                      \
            false_sig,                                                            \
            SI0, SI1)

void foo(int x) {}
void bar(void) {}
double bar2(int x, int y) { return 0.0; }

int main() {
    printf("%d\n", is_string_v("123"));
    printf("%d\n", is_string_v(123123));
    printf("%d\n", has_signature_v(foo, void, int));
    printf("%d\n", has_signature_v(bar, void, int));
    printf("%d\n", has_signature_v(bar2, void, int));
    printf("%d\n", has_signature_v(bar2, double, int, int));

    has_signature_t(bar2, double, int, int) x;

    printf("%s\n", to_string(x));

    has_same_type_t(&bar2, &bar2) y1;
    has_same_type_t(&bar2, &foo) y2;
    has_same_type_t(1, 1) z;

    is_same_t(typeof(&bar2), typeof(&bar2)) z1;
    is_same_t(typeof(&bar2), typeof(&foo)) z2;
    is_same_t(int, typeof(&foo)) z3;
    is_same_t(true_t, true_t) z4;

    and_t(true_t, false_t) aa;

    printf("%s\n", to_string(bool_v(and_t(true_t, false_t))));
    printf("%s\n", to_string(bool_v(and_t(true_t, true_t))));

    auto xxx = (void (*)(int))(0);
    auto xxxx = (SignatureM(void, int))(0);
    auto xxxxx = bool_v(has_same_type_t(xxx, xxxx));
    auto джигурда = bool_v(has_same_type_t((typeof(xxx(3)) *) (0), (void *) (0)));
    auto джигурда2 = bool_v(has_same_type_t((typeof(((void (*)(int))(0))(3)) *) (0), (void *) (0)));
    auto _ = bool_v(is_same_t(result_t(xxx, 42), result_t(xxxx, 4242)));

    auto _______ = (true_sig) (0);
    auto ________ = (false_sig) (0);
    auto _________ = (not_sig(false_sig))(0);
    auto __________ = bool_v(is_same_sig_t(not_sig(false_sig), true_sig));
    auto ___________ = (and_sig(true_sig, false_sig))(0);

    auto s1 = bool_sig_v(true_sig);
    auto s2 = bool_sig_v(not_sig(false_sig));
    auto s3 = bool_sig_v(and_sig(true_sig, false_sig));

    auto select1 = bool_sig_v(select_sig(true_sig, false_sig, _1));
    auto select2 = bool_v(is_same_sig_t(select_sig(true_sig, false_sig, _0), true_sig));

    auto add1 = bool_sig_v(add_sig(true_sig, true_sig, false_sig));
    auto add2 = bool_sig_v(add_sig(true_sig, true_sig, true_sig));

    auto add30 = bool_sig_v(add2_sig(_1, _1, _1, _1, _0, _0));
    auto add31 = bool_sig_v(add2_sig(_1, _1, _1, _1, _0, _1));
    auto add32 = bool_sig_v(add2_sig(_1, _1, _1, _1, _1, _0));
    auto add33 = bool_sig_v(add2_sig(_1, _1, _1, _1, _1, _1));

    printf("%d %d %d %d\n", bool_v_to_int(add33), bool_v_to_int(add32), bool_v_to_int(add31), bool_v_to_int(add30));

    return 0;
}