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#include <stc/algo/coroutine.h>
#include <stdio.h>
#include <stdint.h>
// Demonstrate to call another coroutine from a coroutine:
// First create prime generator, then call fibonacci sequence:
bool is_prime(int64_t i) {
for (int64_t j=2; j*j <= i; ++j)
if (i % j == 0) return false;
return true;
}
struct prime {
int count, idx;
int64_t result, pos;
int cco_state;
};
bool prime(struct prime* U) {
cco_begin(U);
if (U->result < 2) U->result = 2;
if (U->result == 2) {
if (U->count-- == 0) cco_return;
++U->idx;
cco_yield(true);
}
U->result += !(U->result & 1);
for (U->pos = U->result; U->count > 0; U->pos += 2) {
if (is_prime(U->pos)) {
--U->count;
++U->idx;
U->result = U->pos;
cco_yield(true);
}
}
cco_final:
printf("final prm\n");
cco_end(false);
}
// Use coroutine to create a fibonacci sequence generator:
struct fibonacci {
int count, idx;
int64_t result, b;
int cco_state;
};
bool fibonacci(struct fibonacci* F) {
assert(F->count < 94);
cco_begin(F);
F->idx = 0;
F->result = 0;
F->b = 1;
for (;;) {
if (F->count-- == 0)
cco_return;
if (++F->idx > 1) {
int64_t sum = F->result + F->b; // NB! locals only lasts until next cco_yield!
F->result = F->b;
F->b = sum;
}
cco_yield(true);
}
cco_final:
printf("final fib\n");
cco_end(false);
}
// Combine
struct combined {
struct prime prm;
struct fibonacci fib;
int cco_state;
};
bool combined(struct combined* C) {
cco_begin(C);
cco_yield(prime(&C->prm), &C->prm, true);
cco_yield(fibonacci(&C->fib), &C->fib, true);
// Reuse the C->prm context and extend the count:
C->prm.count = 8; C->prm.result += 2;
cco_yield(prime(&C->prm), &C->prm, true);
cco_final: puts("final comb");
cco_end(false);
}
int main(void) {
struct combined comb = {.prm={.count=8}, .fib={14}};
if (true)
while (combined(&comb))
printf("Prime(%d)=%lld, Fib(%d)=%lld\n",
comb.prm.idx, (long long)comb.prm.result,
comb.fib.idx, (long long)comb.fib.result);
else
while (prime(&comb.prm))
printf("Prime(%d)=%lld\n",
comb.prm.idx, (long long)comb.prm.result);
}
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